BR98S0288
Instituto de Fisica Teorica IFT Universidade Estadual Paulista
ANNUAL REPORT
1997
29-40 Instituto de Fisica Teorica Universidade Estadual Paulista
ANNUAL REPORT
1997
INSTITUTO DE FISICA TEORICA DIRECTOR UNIVERSIDADE ESTADUAL PAULISTA JOSE GERALDO PEREIRA RUA PAMPLONA, 145 01405-900 — SAO PAULO VICE-DIRECTOR BRASIL SERGIO FERRAZ NOVAES TEL: 55 (11) 251-5155 FAX: 55 (11) 288-8224 RESEARCH COORDINATOR E-MAIL: [email protected] ROBERTO ANDRE KRAENKEL WEB SITE: HTTP://WWW.IFT.UNESP.BR
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1 General Overview 1 1.1 Brief History 1 1.2 Research Facilities 1 1.2.1 Library 1 1.2.2 Computing Facilities 1 1.3 Main Lines of Research 2 1.3.1 Field Theory 2 1.3.2 Elementary Particle Physics 2 1.3.3 Nuclear Physics 2 1.3.4 Gravitation and Cosmology 2 1.3.5 Mathematical Methods in Physics 2 1.3.6 Non-linear Phenomena 2 1.3.7 Statistical Mechanics 2 1.3.8 Atomic Physics 3
2 Personnel 4 2.1 Faculty 4 2.2 Associate and Postdoctoral Researchers 5 2.3 Visiting Scientists 5 2.4 Staff 6
3 Teaching Activities 7 3.1 Students 7 3.2 Courses 7 3.2.1 First Semester 7 3.2.2 Second Semester 7 3.3 Thesis 8
4 Research Activities 9 4.1 Colloquia and Seminars 9 4.1.1 International 9 4.1.2 National 10 4.2 Research Publications 11 4.2.1 Published Papers 11 4.3 Preprints , 17 1 General Overview 1.1 Brief History The Institute* de Fi'sica Teorica (IFT) was created in 1951 as a Foundation, under the leadership of Jose Hugo Leal Ferreira. It was a pioneer initiative in Theoretical Physics, whose aim was to promote research activities and to train young researchers in the area. In the 50's, the institute received several foreign long term visitors, such as Prof. Carl Friedrich von Weizsacker (first director), Wilhelm Macke and Reinhard Oehme, from the Max Planck Institut fur Physik, Gottingen, Prof. Gert Moliere (also director), Prof. Hans Joos from the Tubingen University and Prof. Werner Giittinger from Aachen, among others. At the end of that decade, Prof. Mituo Taketani from the Rikkyo University, Tokyo, assumed the direction of the institute and brought several Japanese physicists ( e.g. Prof. Yasuhisa Katayama, Tatouki Miyasima, Jun'ichi Osada). In 1958, the Instituto de Ffsica Teorica started to edit the bulletin "Informacao entre Ffsicos" which would give rise to the "Brazilian Journal of Physics". In 1962, Prof. Paulo Leal Ferreira became the first Brazilian director of the institute. After being declared a "Center of Excellence" by the National Research Council (CNPq), the Instituto de Ffsica Teorica began offering Graduate courses in Physics in 1971, and to this moment more than 50 Ph.D. and 100 Master degrees have been bestowed. In the nation wide rankings of the Brazilian Ministry of Education, the graduate studies program of IFT is considered as one of the best in the nation. In the 80's, after a severe economical crisis, the Instituto de Ffsica Tedrica was incorporated to the State University of Sao Paulo (UNESP). The Foundation still remains as an autonomous entity and maintains the buildings and the library. Nowadays, the Instituto de Ffsica Teorica is one of the most productive Brazilian research insti- tutions and has scientific collaborations with several international centers. The research subjects include Mathematical Physics, Field Theory, Elementary Particle Phenomenology, Cosmology and Gravitation, Nuclear Physics, Statistical Mechanics, and Nonlinear Dynamics. The scientific staff has 30 researchers and the Graduate course more than 46 students pursuing Master and Ph.D. degrees.
1.2 Research Facilities 1.2.1 Library The Institute has one of the best Brazilian libraries in theoretical physics. It has around 14.469 books covering the areas of mathematics, the physics of elementary particle and fields, nu- clear physics, mathematical physics, cosmology and gravitation, statistical mechanics, condensed matter and atomic physics. It subscribes more than 79 journal titles.
1.2.2 Computing Facilities The Instituto de Ffsica Teorica has a computer center with a processing capacity of around 500 Mflops. The computing facility includes 1 digital AXP server, 1 high end server RS6000 IBM, 1 high performance paralell server SUN HPC, 5 high performance workstation RS 6000 IBM, SUN SPARC, 40 microcomputers e x-terminals e 14 printers, 20 medium performance workstations RS6000 IBM, 26 microcomputers, 14 printers. The local network is linked via TCP/IP and is connected with the international network via InterNet trough a 256Kbps line. Algebraic software (MathCad, Mathematica, Mapple) and mathematical libraries (IMSL, CERN) besides printing facilities (HP LaserJet IHSi , HP LaserJet II , Laser Print IBM) are available for the whole network.
1.3 Main Lines of Research 1.3.1 Field Theory Higher spin algebras in conformal field theory, W algebras, conformal field theory and inte- grable models in two dimensions, string field theory, Jacobi equations in field theory, symmetries of Toda models and soliton solutions, field theory in curved space, integration in negative dimensions, causal approach and field theory, constrained dynamics and applications.
1.3.2 Elementary Particle Physics Standard model phenomenology, search for new particles and interactions, alternative models for electroweak interactions, neutrino physics.radiative corrections and precision eletroweak mea- surements, vector boson anomalous couplings, astroparticles, relativistic hadronic models, phe- nomenology of quark-gluon plasma signatures, instantons and hadronic spectroscopy, two-body relativistic equations.
1.3.3 Nuclear Physics Nuclear fission, microscopic nuclear models, semiclassical many-body methods, few-body problems, nuclear structure, fusion of heavy ions, electron scattering, giant resonances, restrict dynamic models, nuclear matter at high temperature and densities, hadronic structure, extensions of RPA method, many neutrons nuclei, relativistic many-body methods, q-deformed algebras and many-body physics.
1.3.4 Gravitation and Cosmology Relativistic cosmology, quantum gravity, gauge models as alternative theories for gravitation, classical and quantum fields in curved space-time.
1.3.5 Mathematical Methods in Physics Quantum phase spaces, non-commutative geometry in quantum mechanics and many-body systems, quantum groups and invariant forms, quantization structures, singular potentials in quantum mechanics, renormalization in quantum mechanics.
1.3.6 Non—linear Phenomena Integrable models, soliton equations, chaotic dynamical models and perturbation theory.
1.3.7 Statistical Mechanics Polymer conformation models, superconductivity at high temperatures, combinatorial meth- ods, quantum groups and critical phenomena. 1.3.8 Atomic Physics Positron-atom scattering at low and medium energies. 2 Personnel 2.1 Faculty
Abraham H. Zimerman Full Professor (retired) Adriano A. Natale Full Professor Alfredo P. N. R. Galeão Assistant Professor Alfredo T. Suzuki Assistant Research Professor Antonio J. Accioly Associate Research Professor Bruto M. Pimentel Escobar Associate Research Professor Diogenes Galetti Associate Research Professor Gastão I. Krein Associate Research Professor George E. A. Matsas Assistant Research Professor Gerhard W. Bund Associate Research Professor Gerson Francisco Associate Professor Helio V. Fagundes Full Research Professor José A. C. Alcarás Associate Research Professor José F. Gomes Associate Research Professor José G. Pereira Associate Professor Juan C. Montero Assistant Research Professor Lauro Tomio Associate Research Professor Luiz A. Ferreira Associate Professor Maria C. B. Abdalla Associate Professor Nathan Jacob Berkovits Assistant Professor Oscar J.P. Éboli Full Professor
Paulo L. Ferreira Full Research Professor (retired) Roberto A. Kraenkel Assistant Research Professor Rogério Rosenfeld Assistant Research Professor Ruben Aldrovandi Full Research Professor Sadhan K. Adhikari Full Research Professor Sandra S. Padula Assistant Research Professor Sérgio F. Novaes Associate Research Professor Valdir C. Aguilera-Navarro Full Professor (retired) Vicente Pleitez Associate Professor 2.2 Associate and Postdoctoral Researchers Alexander Belyaev Postdoctoral Fellow Carlos A. da Rocha Postdoctoral Fellow Cláudio M. Maekawa Postdoctoral Fellow Dominique M. Spehler CNPq Associate Researcher Edisom S. Moreira Jr. Postdoctoral Fellow Felice Pisano Postdoctoral Fellow Fernando L. de Campos Carvalho Postdoctoral Fellow Fernando Mori Postdoctoral Fellow Francisco E. M. da Silveira Postdoctoral Fellow Jeferson de Lima Tomazelli Postdoctoral Fellow Marcelo de Moura Leite Postdoctoral Fellow Mirian Batista Postdoctoral Fellow Pradip K. Biswas Postdoctoral Fellow Ricardo I. Medina Bascur Postdoctoral Fellow Ricardo Vazquez Postdoctoral Fellow Samya B. de Paiva Macedo Postdoctoral Fellow Silvana P. Flego Postdoctoral Fellow Thays Lungov Postdoctoral Fellow
2.3 Visiting Scientists B. Talukdar Visva-Bharati, India June-August F. Krmpotic Univ. Nacional de La Plata, Argentina March G. Sotkov Univ. Estadual do Rio de Janeiro, Brazil January-February H. Nunokawa Univ. Valencia, Spain August J. Haidenbauer Julich Univ., Germany November J. Sanchez Guillen Univ. Santiago de Compostela, Spain April J. Tjon Univ. of Utrecht, Netherlands August J. Zanelli Centro de Estudos Científicos de Santiago, Chile November J. Luis Miramontes Antas Univ. Santiago de Compostela, Spain February J. Wagner Furtado Valle Univ. de Valencia, Spain December M. C. Gonzalez-Garcia Univ. de Valencia, Spain January-December M. A. Manna Univ. Montpellier, France September 2.4 Staff
Alexandre A. dos Reis Library Ana Luiza Pereira da Silva Library Antonio Peres Rubbi f Reception Edna Maria de Oliveira Lacerda PBX Operator Jose Francisco Simoes Matias Administration Laercio Carlos Pastore Administration Lucimara Desidera Systems Analyst Luis Carlos Aparecido Diotto Driver Luzinete Aparecida Martins Secretary Marcelo Martins lasniswski Secretary Maria Jose Trombini de Souza Systems Analyst Marina Veiga Library Meire Cristina F. Passos Library Orides Jorge Pereira General Services Renata Aparecida F. Arruda Silva PBX Operator Rosane Simoes Secretary Vilma Nunes de Oliveira Secretary Walter Matheos Junior System Manager 3 Teaching Activities
3.1 Students The Instituto de Fisica Teorica had a total of 31 Ph.D. and 15 Master students during 1997. Most of them had fellowships of different Brazilian financial agencies, like Fundacao de Amparo a Pesquisa do Estado de Sao Paulo — FAPESP (20), Conselho Nacional de Desenvolvimento Cienti'fico e Tecnologico — CNPq (12) and Coordenacao de Aperfeicoamento de Pessoal de Ni'vel Superior — CAPES (9).
3.2 Courses The following courses were offered during 1997 :
3.2.1 First Semester 1. Quantum Mechanics I
2. Introduction to Supersymmetry
3. Classical Mechanics
4. Statistical Mechanics
5. Elementary Particle Physics I
6. Field Theory at Finite Temperature
7. Classical Field Theory
8. Group Theory with Applications to Nuclear Structure
3.2.2 Second Semester 1. Kac-Moody Algebras in Quantum Field Theory
2. Algebras and Lie Groups
3. Nuclear Physics I
4. Elementary Particle Physics II
5. General Relativity
6. Chaos Theory and Applications
7. Quantum Field Theory I
8. Quantum Mechanics II
9. Topics in Elementary Particle Physics 3.3 Thesis 1. Luís Carlos Bassalo Crispino — Master "Grupos de Newton-Hooke e outros grupos cinemáticos" Advisor: Prof. Ruben Aldrovandi
2. Marcos Cardoso Rodriguez — Master "Assimetria + - no espalhamento Moller no modelo padrão" Advisor: Prof. Vicente Pleitez
3. Carlos Alberto Tello Echevarria — Master "Distribuições nucleares com correlação do método de coordenadas geradoras" Advisor: Prof. Diogenes Galetti
4. Antonio Cândido de Camargo Guimarães Jr. — Master "Contribuições térmicas para a radiação de Spin—Flip e depoiarização de elétrons" Advisor: Prof. George Emanuel Avraam Matsas
5. Cristiane Grala Roldão— Master "Interferometria de K+K+ a energias do AGS" Advisor: Profa. Sandra dos Santos Padula
6. Cláudia lanes Barbosa — Ph.D. "Estudo de flutuações estatísticas na transição caos—ordem" Advisor: Prof. Celso Luiz Lima
7. Eliezer Batista — Ph.D. "Deformações quânticas de algebras conformes" Advisor: Prof. José Francisco Gomes
8. Eduardo de Moraes Gregores — Ph.D. "Busca de subestrutura em colisões elétron-fóton" Advisor: Prof. Sérgio Ferraz Novaes
9. Francisco Eugênio Mendonça da Silveira — Ph.D. "Modeles reduzidos de buracos negros em (1+1) Dimensões" Advisor: Prof. Abraham Hirsz Zimerman
10. Antonio Eduardo Assis Amorin — Ph.D. "Aspectos universais em sistemas de três corpos" Advisor: Prof. Lauro Tomio 4 Reseach Activities 4.1 Colloquia and Seminars We had a total of 43 colloquia and seminars during 1997, including:
4.1.1 International
1. "Metodos Assintoticos e Pertubativos em Sistemas Dispersivos Lineares e Ndo-Lineares" Prof. Miguel Manna - Universidade de Montpellier 2. "0 Relaxamento Metaestdvel de Modelos de Ising Cineticos e Gotas de Wulff' Prof. Roberto H. Schonmann - UCLA 3. "Energy and Tempus as Canonical Variables and some Applications" Prof. Donald H. Kobe - Univ. of North Texas, USA 4. "Solitonic Integrable Pertubations of Conformal Field Theories" Prof. Jose L. Miramontes - Univ. de Santiado de Compostela, Spain 5. "Superconductivity as a Bose-Einstein Condensation" Prof. Manuel de Llano - Univ. Nacional Autonoma de Mexico 6. "Renormalization Group and Flavor Production From Quark-Gluon Plasma' Prof. Johann Rafelski - Univ. of Arizona, Tucson, USA 7. "Bringing up a Quantum Baby" Prof. A. P. Balachandran - Syracuse University , USA 8. "Noncommutative Geometry, the Standard Model and Unification" Prof. Fedele Lizzi - Napoli/Oxford 9. "Determinants of Laplacians on Hyperbolic 3-manifolds Associated with Quantum Fields" Prof. A. A. Bytsenko - State Technical Univ. St. Petesburg 10. "The Little Bang: Recreating the Early Universe in High Energy Heavy-Ion Collisions" Prof. Ulrich Heinz - University of Regensburg, Germany 11. "Limits on Anomalous Gauge Boson Coupling from Higgs Boson Production at the Tevatron Collider" Profa. Concha Gonzales-Garcia - IFT/University of the Valencia 12. "Highlights in Quantum Gravity: Achievements and Perspectives" Prof, llya L. Shapiro - Tomsk State University 13. "Meson-Meson and Meson-Nucleon Scattering and the Structure of the Hadron " Prof. J. Haindenbauer - KFA, Juelich, Germany 14. "Single Top, Higgs Boson and Physics Beyond the Standard Model at the Tevatron " Prof. Alexander Belyaev - IFT, Brasil 15. "On Integrable Structure in Conformal Field Theory" Prof. Alexander A. Belavin - Instituto Landau, Moscou, Russia 4.1.2 National
1. "0 que é um Foton " Prof. Herch Moyses Nussenzveig - UFRJ 2. "High Energy Neutrinos from Topological Defects" Prof. Ricardo Vazquez - IF-USP, Brasil 3. "Neutrinos Massivos" Prof. Francisco Krmpotic - Univ. de La Plata, Argentina 4. "Expansão Urbana e Especulação Imobiliária em São Paulo" Profa. Raquel Gleser - FFLCH/USP 5. "Métodos Algébricos em Ciências Moleculares" Prof. Esmerindo de Souza Bernardes- IFSC/USP 6. "Medindo o Spin Anômalo em Espalhamento elástico ep ou v ou profundamente inelástico lp" Prof. Fernando Steffens - IF/USP 7. "Complementando o Principio da Complementaridade" Prof. Osvaldo Pessoa Jr. - IEA/USP e CLE/UNICAMP 8. "Bioética" Prof. Marco Segre - USP 9. "Simulação em Computadores de Teorias Variacionais do Hélio Liquido e Sólido" Prof. Silvio Vitiello - UNICAMP 10. "Uma Versão Regularizada de Modelo Sigma Linear" Profa. Silvana P. Flego - IFT 11. "A Economia como uma Ciência Formal" Prof. Samuel Pessoa - FEA/USP 12. "Tomografia Magnética do Sol Através do Fluxo de Neutrinos" Prof. Marcelo Guzzo - UNICAMP 13. "Evolução do Programa Antártico Brasileiro (PROANTAR) e Perspectivas Futuras" Prof. Antonio Carlos Rocha Campos - Instituto de Geociências - USP 14- "Fundamentos Axiomáticos de La Mecânica Cuântica: Um Enfoque Realista" Prof. Hector Vucetich - Universidade de La Plata - Argentina 15. "Limiar de Produção de Pions em Espalhamento Proton-Proton e a Contagem Quiral de Potências" Prof. Carlos A. da Rocha - IFT 16. "Integrabilidade em Dimensões Maiores que Dois" Prof. Luiz Agostinho Ferreira - IFT
10 11. "Representação de Weyl na Mecânica Clássica e na Mecânica Quântica" Prof. Alfredo M. Ozorio de Almeida - CBPF 18. "Algumas Considerações Sobre as Ações do CNPq e do Comitê Assessor de Física e Astronomia" Prof. José D'Albuquerque e Castro - UFF 19. "Sobre a Origem da Estrutura Mosaica do DNA: Um Modelo de Mecânica Estatística" Profa. Carla Goldman - IF/USP 20. "A Comunicação Animal, do Sinal ao Símbolo" Prof. Cesar Ades - Faculdade de Psicologia - USP 21. "Sobre a Experiência Numérica de FERMI-PASTA-ULAM" Prof. Abraham H. Zimerman - IFT 22. "Teoria de Campos Aplicada a Fenômenos Críticos" Prof. Carlos Eugênio Carneiro - IF/USP 23. "Considerações Epistemológicas Sobre a Natureza do Tempo" Prof. Hector Saint-Pierre - Núcleo de Estudos Estratégicos - UNICAMP/UNESP- Franca 24- "Ondas Gravitacionais em um Meio Térmico" Prof. Fernando T. C. Brandt - IF/USP 25. "Invariantes Topológicos Torsionais e Anomalias" Prof. Jorge Zanelli - Centro de Estudos Científicos de Santiago, Chile 26. "Os projetos Gemini e Soar" Prof. João Steiner - IAG/USP e LNA 27. "Caos e Bifurcações em Bilhares Quânticos em Campos Magnéticos" Prof. Marcus Aguiar - UNICAMP 28. "The Supersymmetric Itzykson-Zuber Integral" Prof. Ricardo Medina - IFT
4.2 Research Publications 4.2.1 Published Papers 1. A. A. Natale and P. S. Rodrigues da Silva "Compatibility of a model for the QCD-Pomeron and chiral-symmetry breaking phenomel- ogies" Phys. Lett. 390B, 378-384 (1997) 2. A. A. Natale and P. S. Rodrigues da Silva "Critical coupling for dynamical chiral-symmetry breaking with an infrared finite gluon propagator" Phys. Lett. 392B, 444-451 (1997)
11 3. A. A. Natale "Short distance QCD contribution to the electroweak mass differences of pions" Phys. Rev. D55, 7309-7311 (1997)
4. A. A. Natale and P. S. Rodrigues da Silva "Fixed points and vacuum energy of dynamically broken gauge theories" Modern Phys. Lett. A12, 2511-2521 (1997)
5. A. Bartl, W. Porod, F. de Campos, M. A. Garcia-Jareno, M. B. Magro, J. W. F. Valle and W. Majerotto "Signatures of spontaneous breaking of R parity in giuino cascade decays at LHC" Nucl. Phys. B502, 19-36 (1997)
6. A. E. A. Amorim, L. Tomio and T. Frederico "Universal aspects of Efimov states and light three body halo nuclei" Phys. Rev. C56, R2378-R2381 (1997)
7. A. Higuchi, D. Sudarsky and G. E. A. Matsas "Do static sources outside a Schwarzcshild black hole radiate?" Phys. Rev. D56, R6071-R6075 (1997)
8. A. J. Accioly, R. Aldrovandi, S. F. Novaes, D. Spehler and H. Mukai "On the long standing issue of an R^2 coupling between gravity and massless free scalar field" Progr. Theor. Phys. 97, 121-128 (1997)
9. A. J. Accioly, A. D. Azeredo, C. M. L. de Aragao and H. Mukai "Simple prescription for computing the stress-energy tensor" Clas. Quantum Grav. 14, 1163-1166 (1997)
10. A. J. Accioly and H. Mukai "Fermion helicity flip in higher-derivative electromagnetism" Z. Phys. C 75, 187-191 (1997)
11. A. J. Accioly and H. Mukai "Podolsky's higher-order electromagnestim from first principles" Nuovo Cim. B112, 1061-1086 (1997)
12. A. J. Accioly and H. Mukai "On the dissimilarity between the algorithms for computing the symmetric energy-momentum tensor in ordinary field theory and general relativity" Nuovo Cim. B112, 639-643 (1997)
13. A. J. Accioly "Energy and momentum for electromagnetic field described by three outstanding eletrody- namics" Amer. J. Phys. 65, 882-887 (1997)
12 14. A. P. Galeao, P. L. Ferreira and J. A. C. Alcaras "Two-Body Dirac equation approach to the Deuteron" Intern. J. Mod. Phys. E6, (1997)
15. A. T. Suzuki and A. G. M. Schmidt "Negative dimensional integration: 'Lab-testing at two-loops" J. of High Energy Phys. 09, 001-011 (1997)
16. B. E. Palladino e P. L. Ferreira "Fundamental fermion masses from deformed SUq(2) triplets" Nuovo Cim. A110, 303-314 (1997)
17. C. A. da Rocha, G. Krein and L. Wilets "Ghost poles in the nucleon propagator in the linear a model approach" Nucl. Phys. A616, 625-647 (1997)
18. C. E. Cordeiro, A. Delfino and J. Dey "Thermodynamics of pion gas using states predicted from K deformed Poincare algebra" Modem Phys. Lett. A12, 1901-1908 (1997)
19. C. F. de Araujo, L. Tomio, S. K. Adhikari and T. Frederico "Application of renormalization to potential scattering" J. Phys. A30, 4687-4700 (1997)
20. C. Montes, A. Mikhailov, A. Picozzi and F. Ginovart "Dissipative three-wave structures in stimulated backscattering I" Phys. Rev. E55, 1086-1091 (1997)
21. D. Galetti, C. L. Lima, J. T. Lunardi and B. M. Pimentel "Q-deformed fermionic Lipkin Model at Finite Temperature" Physica A242, 501-508 (1997)
22. D. Hadjimichef and F. Kokubun "Colletive scattering of massive stars and higher order gravity" Phys. Rev. D55, 733-738 (1997)
23. F. Arash and L. Tomio "Probing SU(920) symmetry breaking in nucleon sea" Phys. Lett. 401B, 207-212 (1997)
24. F. A. B. Coutinho, Y. Nogami and J. F. Perez "Generalized point interactions in one-dimensional quantum mechanics" J. Phys. A30, 3937-3945 (1997)
25. F. de Campos, S. M. Lietti, S. F. Novaes and R. Rosenfeld "Anomalous couplings in e+e~ —> W+W~j at LEP2 and NLC" Phys. Rev. D56, 4384-4391 (1997)
26. F. de Campos, M. C. Gonzales-Garcia and S. F. Novaes "Limits on the anomalous coupling from Higgs boson production at the Tevatron collider" Phys. Rev. Lett. 79, 5210-5213 (1997)
13 27. G. W. Bund, S. S. Mizrahi, M. C. Tijero "Colllisional semiclassical approximations in phase-space representation" Phys. Rev. A56, 2825-2832 (1997) 28. H. Aratyn, L. A. Ferreira, J. F. Gomes and A. H. Zimerman "Constrained KP models as integrable matrix hierarchies" J. Math. Phys. 38, 1559-1576 (1997)
29. J. Alfaro, R. Medina and L. F. Urrutia "Orthogonality relations and supercharacter formulas of U(m/n) representations" J. Math. Phys. 38, 5319-5349 (1997)
30. J. A. C. Alcaras, J. Tambergs, J. Ruza and T. Krasta "The evaluation of effective nucleon-nucleon potencial and the description of a-cluster type nuclei in the restricted dynamics approach" Intern. J. Mod. Phys. E6, (1997)
31. J. A. C. Alcaras, J. Tambergs, T. Krasta, J. Ruza and 0. Katkevicius "The restricted dynamics approach for A < 60 nuclei and the estimation of microscopic values of phenomenological collective model parameters" Braz. J. Phys. 27, 425-447 (1997) 32. J. C. Montero, A. A. Natale and P. S. Rodrigues da Silva "Infrared finite solutions for the gluon propagator and the QCD vacuum energy" Phys. Lett. 406B, 130-136 (1997)
33. J. Dey, M. Dey, T. Frederico and L. Tomio "Scaling law for baryon coupling to its current and its possible applications" Modern Phys. Lett. A12, 2193-2201 (1997)
34. J. -L. Ballot, M. R. Robilotta and C. A. da Rocha "Two pion exchange nuclear potential: chiral cancellations" Intern. J. Mod. Phys. E6, 83-88 (1997)
35. J. L. Boldo, B. M. Pimentel and J. L. Tomazelli "Infrared dynamics in (2+1) dimensions" Canadian J. Phys. 75, 1-8 (1997)
36. J. L. Boldo, B. M. Pimentel and J. L. Tomazelli "Causal Phase in QED3" Intern. J. Theor. Phys. 36, 1591-1600 (1997) 37. J. P. de Melo, T. Frederico, L. Tomio and A. Dorokhov "Quark antiquark correlation in the pion" Nucl. Phys. A623, 456-470 (1997) 38. L. A. Ferreira, J. L. Miramontes and J. S. Guillen "Tau functions and dressing transformations for zero curvature affine integrable equations" J. Math. Phys. 38, 882-901 (1997)
39. L. C. Chamon, D. Pereira, M. S. Hussein, M. A. C. Ribeiro e D. Galetti "Nonlocal description of the nucleus-nucleus interaction" Phys. Rev. Lett. 79, 5218-5221 (1997)
14 40. M. A. C. Ribeiro, L. C. Chamon, D. Pereira, M. S. Hussein and D. Galetti "Pauli nonlocality in heavy-ion rainbow scattering: a further test of the folding model" Phys. Rev. Lett. 78, 3270-3273 (1997)
41. M. A. F. Gomes and S. K. Adhikari "Quantization rules for bound states in quantum wells" J. Phys. B30, 5987-5997 (1997)
42. M. C. Gonzalez-Garcia and S. F. Novaes "Excited fermion contribution to Z° physics at one loop" Nucl. Phys. B486, 3-22 (1997)
43. M. C. Gonzalez-Garcia and S. F. Novaes "Bounds on contact interations from LEP1 data and the high-Q2 HERA events" Phys. Lett. 407B, 255-258 (1997)
44. M. C. Gonzalez-Garcia, E. M. Gregores and S. F. Novaes "Discriminating new physics scenarios at NLC: The Role of Polarization" Phys. Rev. D56, 2920-2927 (1997)
45. M. M. Leite and V. 0. Rivelles "Black holes in the gauge theoretic formulation of dilatonic gravity" Phys. Lett. 392B, 305-310 (1997)
46. M. Malheiro, M. Dey, A. Delfino and J. Dey "The connection between the nuclear matter mean field equation of state and the quark and gluon condensates at high density" Phys. Rev. C55, 521-524 (1997)
47. N. Berkovits and M. M. Leite "First massive state of the superstring in superspace" Phys. Lett. 415B, 144-148 (1997)
48. N. Berkovits and R. Medina "Pasti-Sorokin-Tonin actions in the presence of sources" Phys. Rev. D56, 6388-6390 (1997)
49. N. Berkovits "Ramond-Ramond central charges in the supersymmetry algebra of the superstring" Phys. Rev. Lett. 79, 1813-1816 (1997)
50. N. Berkovits and W. Siegel "Covariant field theory for self-dual strings" Nucl. Phys. B505, 139-152 (1997)
51. N. Berkovits "Super-Maxwell actions with manifest duality" Phys. Lett. 398B, 79-82 (1997)
52. N. Berkovits "Local actions with electric and magnetic sources" Phys. Lett. 395B, 28-35 (1997)
15 53. N. Berkovits and W. Siegel "Extra dimensions in superstring theory" Nucl. Phys. B507, 731-745 (1997)
54. O. J. P. Eboli, M. C. Gonzalez-Garcia and S. F. Novaes "Limits on anomalous top couplings from Z pole physics" Phys. Lett. 415B, 75-82 (1997) 55. P. Chaudhuri and S. K. Adhikari "Resonance in positron-helium scattering at medium energy" J. Phys. B30, L81-L85 (1997)
56. R. A. Kraenkel, M. A. Manna, J. C. Montero and J. G. Pereira "The role of the KdV hierarchy in the N-soliton dynamics of the shallow water wave equa- tion" J. Phys. Soc. of Japan 66, 1277-1281 (1997)
57. R. Aldrovandi and L. A. Saeger "Fourier duality as a quantization principle" Intern. J. Theor. Phys. 36, 345-383 (1997)
58. R. Aldrovandi and L. A. Saeger "Projective Fourier duality and Weyl quantization" Intern. J. Theor. Phys. 36, 573-612 (1997) 59. S. K. Adhikari and A. Ghosh "Scaling in BCS to Bose crossover problem in different partial waves" Phys. Rev. B55, 1110-1113 (1997)
60. S. K. Adhikari and A. Ghosh "Renormalization in nonrelativistic quantum mechanics" J. Phys. A30, 6553-6564 (1997)
61. S. Paiva, Y. Hama and T. Kodama "Fluctuation effects in initial conditions for hydrodynamics" Phys. Rev. C55, 1455-1462 (1997)
62. V. C. Aguilera-Navarro and E. Ley Koo "Variational-rotational analysis of supersingular plus quadratic A/(r4 + r2) potentials" Intern. J. Theor. Phys. 36, 157-176 (1997)
63. V. C. de Andrade, J. G. Pereira "Gravitational Lorentz force and the description of the gravitational interaction" Phys. Rev. D56, 4689-4695 (1997)
64. Y. Hama, T. Kodama and S. Padula "Hanbury-Brown-Twiss interferometry for sonoluminescence bubble" Phys. Rev. A56, 2233-2236 (1997)
65. Y. Hama and S. Paiva "Inelasticity distributions in high-energy p-nucleus collisions" Phys. Rev. Lett. 78, 3070-3073 (1997)
16 4.3 Preprints
IFT - P.001/97
On the Long Standing Issue of an R AJ.Accioly, R.Aldrovandi, S.F.Novaes, D.Spehler1, H.Mukai2 1 Universite Louis Pasteur, I.U.T., 3 rue St Paul, 67300 Strasbourg, France 2 Departamento de Fisica, Fundagdo Universidade Estadual de Maringd, Av. Colombo 5790, 87020-900, Maringd, Pr, Brazil PUBLISHED IN PROGRESS OF THEORETICAL PHYSICS Using 2 body trees on a flat space background, it is shown that the actions A \g, 4>] = J d^x^g- [£ + i (g^d^d^ + \Rcj>2) ] and A [g, 4>] = [ describe the same theory at the tree-level in this case. We also demonstrate the quantum equiv- alence (at one-loop) of the barred and unbarred systems for A = —1/6 (conformal coupling). [1] LAmendola,/%s.Z;eft. B301, 175 (1993),and references therein . [2] I.LBuchbinder, S.D.Odintsov and I.L.Shapiro, Effective Action in Quantum Gravity (IOP publishing Ltd., 1992). [3] AJ.Accioly, U.F.Wichoski, S.F.Kwok and N.L.P.Pereira da Silva, Class. Quantum Grav. 19, L215 (1993); A.J.Accioly, D.Spehler, S.F.Novaes, S.F.Kwok and H.Mukai, Phys.Rev. D 51, 931 (1995). IFT - P.002/97 Polarization in Fermion Scattering A.J.Accioly, E.C. de Rey Neto, H.S.BIas Achic, H.Mukai1 1 Departamento de Fisica, Fundacdo Universidade Estadual de Maringd, Av. Colombo 5790, 87020-900, Maringd, Pr, Brazil To APPEAR IN BRAZILIAN JOURNAL OF PHYSICS The behaviour of the helicity of an initially left-handed beam of massive fermions first interacting with a Coulomb field and then with a charged scalar particle via a photon exchange is analysed. It is found that in both cases the massive fermions have their helicity flipped, while massless fermions seem to be unaffected by the electromagnetic field as far as their helicity is concerned. 17 [1] W. Greiner and J. Reinhardt, Quantum Electrodynamics (Springer-Verlag, 1994). [2] J. D. Bjorken and S. D. Drell, Relativistic Quantum Mechanics (McGraw-Hill, Inc., 1964). [3] F. Mandl and G. Shaw, Quantum Field Theory (John Wiley & Sons, Ltd., 1986). IFT - P.003/97 "Vacuum Instability" and Tachyon Poles in Non-Asymptotically Free Field Theories: a Quantitative Connection S. P. Flego and M. C. IMemes l 1 Departamento de Fisica, ICEX, Universidade Federal de Minas Gerais, C.P. 702, CEP 30.161-970, Belo Horizonte, MG, Brasil. SUBMITTED TO PHYS. LETT. B One-fermion-loop corrections are known to destabilize the translationally invariant vacuum in all renormalizable theories. The inclusion of one-boson-loop corrections can only eliminate the problem in asymptotically free field theories. One of the manifestations of this instability is the presence of tachyon poles in the boson propagators. In the present work we derive a quantitative relation between the tachyonic pole positions and the vacuum fluctuations corrections at the one loop order for such theories. An application to the Linear Sigma Model is performed. [1] T.D.Cohen, M.K.Banerjee and C.-Y.Ren Phys.Rev. C 36 (1987) 1953. [2] R.J.Perry, Phys.Lett. B 199 (1987) 489. [3] S.P.FIego, A.H.Blin, B.Hiller and M.C.Nemes, Z. Phys.A 352 (1995)197. IFT - P.004/97 Discretizing the Deformation Parameter in the su(2)q Quantum Algebra B.E.Palladino and P.LealFerreira PUBLISHED IN J.PHYS.A We show in this work that the condition [2j+l]q = Nq(j) = integer implies the discretization 18 of the deformation parameter alpha, where q=exp(alpha) for the case of the q-algebra su(2)q. The discretization replaces the continuum associated to alpha by an infinite sequence of values which are obtained and listed for the values of j which label the irreps of su(2)q. The properties of Nq(j) are discussed in some detail, including its role as a trace, which conducts to the Clebsch- Gordan series for the direct product of irreps. The consequences of this process of discretization are discussed and its possible applications are pointed out. The method of discretization could be developed in the context of other unitary quantum groups as well. [1] L. C. Biedenharn, J. Phys A 22, 873 (1989). [2] A. J. Macfarlane, J. Phys A 22, 4581 (1989). [3] B. E. Palladino and P. Leal Ferreira, IFT-P038/96. I FT - P.005/97 Aspects of Solitons in Affine Integrable Hierarchies Luiz A. Ferreira and J. Sanchez Guillen1 1 Facultad de Fisica, Universidad de Santiago de Compostela, 15706 Santiago de Compostela, Spain TWO TALKS PRESENTED BY THE AUTHORS AT THE "INTERNATIONAL WORKSHOP ON SELECTED TOPICS OF THEORETICAL AND MODERN MATHEMATICAL PHYSICS - SIMI/96", TBILISI, GEORGIA, SEPTEMBER/96 We consider a very large class of hierarchies of zero-curvature equations constructed from affine Kac- Moody algebras Q. We argue that one of the basic ingredients for the appearance of solitons solutions in such theories is the existence of "vacuum solutions" corresponding to Lax operators lying in some abelian (up to central term) subalgebra of Q. Using the dressing transformation procedure we construct the solutions in the orbit of those vacuum solutions, and conjecture that the soliton solutions correspond to some special points in those orbits. The generalized tau-function for those hierarchies are defined for the integrable highest weight representations of Q, and it applies for any level of the representation and it is independent of its realization. We illustrate our methods with the recently proposed non abelian Toda models coupled to matter fields. A very special class of such theories possess a U(l) Noether charge that, under a suitable gauge fixing of the conformal symmetry, is proportional to a topological charge. That leads to a mechanism that confines the matter fields inside the solitons. [1] L.A. Ferreira, J.L. Miramontes and J. Sanchez Guillen, J. Math. Phys. 38, (1997), 2, hep- th/9606066. [2] L.A. Ferreira, J-L. Gervais, J. Sanchez Guillen and M.V. Saveliev, Nucl. Phys. B470 (1996) 236, hep-th/9512105. [3] G. Wilson, Phil. Trans. R. Soc. Lond. A 315 (1985) 19 IFT - P.006/97 Some Comments on the bi(tri)-Hamiltonian Structure of Generalized AKNS and DNLS Hierarchies* H.S. Bias Achic^ , LA. Ferreira, J.F. Gomes and A.H. Zimerman l We give the correct prescriptions for the terms involving dx (x — y), in the Hamiltonian structures of the AKNS and DNLS systems, in order for the Jacobi identities to hold. We also establish that the sl(2) AKNS and DNLS systems are tri-Hamiltonians and construct two compatible Hamiltonian structures for the sl(3) AKNS system. We also give a derivation of the recursion operator for the sl(n + 1) DNLS system. [1] A.P. Fordy and P.P. Kulish, Comm. Math. Physics 89 (1983), 427. [2] F. Magri; Journal of Math. Physics 19 (1978), 1156. [3] H. Aratyn, J.F. Gomes and A.H. Zimerman, Journal of Math. Physics 36 (1995), 3419-3442, hep-th/9408104. IFT - P.007/97 Majoron Emitting Neutrinoless Double Beta Decay in the Electroweak Chiral Gauge Extensions F. Pisano and S. Shelly Sharma1 1 Departamento de Fisica, Universidade Estadual de Londrina, 86051-970, Londrina, PR Brazil Fundamental mechanisms for Majoron emitting neutrinoless double beta decay in SU(3)c <8> G\y® U(l) models, for electroweak flavor chiral extensions, Gw = SU(3)L and SU(4)x, are pointed out. Both kinds of known Majoron emitting processes, charged Majoron emitting where the massless Nambu-Goldstone boson itself carries lepton charge, L = —2, and the ordinary Majoron emitting coming from a direct electron-majoron Yukawa like coupling are found possible. [1] F. Pisano and V. Plitez, Phys. Rev. D 46, 410 (1992). [2] F. Krmpotic and S. Shelly Sharma, Nucl. Phys. A 572, 329 (1994). [3] V. Pleitez and M. D. Tonasse, Phys. Rev. D 48, 5274 (1993). 'Work supported in part by CNPq •Supported by FAPESP 20 IFT - P.008/97 Vanishing Cosmological Constant in Elementary Particles Theory F. Pisano and M. D. Tonasse1 1 Instituto de Fisica, Universidade do Estado do Rio de Janeiro, Rua Sao Francisco Xavier 524 - 20550-000, Rio de Janeiro, RJ, Brazil The quest of a vanishing cosmological constant is considered in the simplest anomaly-free chiral gauge extension of the electroweak standard model where the new physics is limited to a well defined additional flavordynamics above the Fermi scale, namely up to a few TeVs by matching the gauge coupling constants at the electroweak scale, and with an extended scalarland. In contrast to the electroweak standard model, it is shown how the extended scalar sector of the theory allows a vanishing or a very small cosmological constant. The details of the cancellation mechanism are presented. At accessible energies the theory is indistinguishable from the standard model of elementary particles and it is in agreement with all existing data. [1] F. Pisano and V. Pleitez, Phys. Rev. D 46, 410 (1992). [2] S. Weinberg, Theories of the Cosmological Constant, Talk given at the conference Critical Dialogues in Cosmology, Princeton University, June 24-27, 1996. Available in astro-ph/9610044. [3] V. Pleitez and M. D. Tonasse, Phys. Rev. D 48, 5274 (1993). IFT - P.009/97 The Structures Underlying Soliton Solutions in Integrable Hierarchies* Luiz A. Ferreira§ We point out that a common feature of integrable hierarchies presenting soliton solutions is the existence of some special "vacuum solutions" such that the Lax operators evaluated on them, lie in some abelian subalgebra of the associated Kac-Moody algebra. The soliton solutions are constructed out of those "vacuum solitons" by the dressing transformation procedure. *Talk presented at the I Latin American Symposium on High Energy Physics, I SILAFAE, November/96, Merida, Mexico § Partially supported by CNPq 21 [1] L.A. Ferreira, J.L. Miramontes and J. Sanchez Guillen, Journal of Mathematical Physics 38 # 2, (1997) , hep-th/9606066. [2] G. Wilson, Phil. Trans. R. Soc. Lond. A 315 (1985) 383; Habillage et functions r C. R. Acad. Sc. Paris 299 (I) (1984) 587; The r-Functions of the gAKNS Equations, in "Verdier memorial conference on integrable systems" (O.Babelon, P.Cartier, and Y.Kosmann-Schwarzbach, eds.), Birkhauser (1993) 131-145.. [3] E. Date, M. Jimbo, M. Kashiwara, T. Miwa, Proc. Japan. Acad. 57 (1981) 3806; Physical (1982) 343; Publ. RIMS Kyoto University 18, (1982) 1077; M. Semenov-Tian-Shansky, Func- tional Analysis and its Application 17 (1983) 259; Publ. RIMS Kyoto Univ. 21 (1985) 1237. IFT - P.010/97 Signatures of Spontaneous Breaking of R-Parity in Gluino Cascade Decays at LHC 1 etc. l A. Bartl. W. Porod, F. de Campos, 2 M. A. Garcia-Jareno, M. B. Magro, J. W. F. Valle and 3 W. Majerotto 1 Institui für Theoretische Physik, University of Vienna - Austria 2 Instituto de Física Corpuscular - C.S.I.C., Departament de Física Teórica - Universitat de Valencia - Spain 3 Institui für Hochenergiephysik, Akademie der Wissenschaften - Austria PUBLISHED IN NUCLEAR PHYSICS B We study the pattern of gluino cascade decays in a class of supersymmetric models where R-parity is spontaneously broken. We give a detailed discussion of the R-parity violating decays of the lightest neutralino, the second lightest neutralino and the lightest chargino. The multi-lepton and same-sign dilepton signal rates expected in these models are compared with those predicted in the Minimal Supersymmetric Standard Model. We show that these rates can be substantially enhanced in broken R-parity models. [1] H. Haber and G. Kane, Phys. Rep. 117, 75 (1985). [2] A. Masiero and J. W. F. Valle, Phys. Lett. B251, 273 (1990). [3] J. C. Romão, F. de Campos, M. A. García-Jarenõ, M. B. Magro, J. W. F. Valle, Nucl. Phys. B482), 3 (1996). /ÍT-P.011/97 HBT Interferometry for Sonoluminescence Bubble Yogiro Hama1, Takeshi Kodama2 and Sandra S. Padula 1 Instituto de Física, Universidade de São Paulo 22 2 Instituto de Fisica, Universidade Federal do Rio de Janeiro PUBLISHED IN PHYS. REV. A The two-photon correlation of the light pulse emitted from a sonoluminescence bubble is discussed. It is shown that several important information about the mechanism of light emission, such as the time-scale and the shape of the emission region could be obtained from the HBT interferometry. We also argue that such a measurement may serve to reject one of the two currently suggested emission mechanisms, i.e., thermal process versus dynamical Casimir effect. [1] D.F. Gaitan and L.A. Crum, J. Acoust. Soc. Am., Supple. 1 87, S141 (1990), D.F. Gaitan, L.A. Crum, C.C. Curch and R.A.Roy, J. Acoust. Soc. Am. 91, 3166 (1992); L.A. Crum, Physics Today, Sep. (1994). [2] R. Hanbury Brown and R.Q. Twiss, Phil. Mag. Ser. 7, Vol. 45, 663 (1954). [3] D. Neuhauser, Phys. Lett. B182, 289 (1986); S. Trentalange and S.U. Pandey, J. Acoust. Soc. Am. 99, 2439 (1996); C. Slotta and U. Heinz, preprint TPR-96-22, nucl-th/9610016. IFT - P.012/97 Collisional Semiclassical Approximations in Phase-Space Representation G. W. Bund. S. S. Mizrahi1, M. C. Tijero2 1 Universidade Federal de Sao Carlos 2 PUC de Sao Paulo PUBLISHED IN PHYS. REV. A The Gaussian Wave-Packet phase-space representation is used to show that the expansion in powers of h of the quantum Liouville propagator leads, in the zeroth order term, to results close to those obtained in the statistical quasiclassical method of Lee and Scully in the Weyl-Wigner picture. It is also verified that propagating the Wigner distribution along the classical trajectories the amount of error is less than that coming from propagating the Gaussian distribution along classical trajectories. [1] H. W. Lee and M. 0. Scully, J. Chem. Phys. 73, 2238 (1980). [2] G. W. Bund, S. S. Mizrahi and M. C. Tijero, Phys. Rev. A 53, 1191 (1996). [3] S. S. Mizrahi, Physica A 135, 237 (1986). IFT - P.013/97 The Restricted Dynamics Approach for A < 60 Nuclei and the Estimation of Microscopic Values of Phenomenological Collective Model Parameters J. A. Castilho Alcaras. J. Tambergs1 , T. Krasta1 , J.Ruza1, 0. Katkevicius2 23 1 Nuclear Research Center, LV-2169, Salaspils, Latvia 2 Institute of Theoretical Physics and Astronomy, 2600 Vilnius, Lithuania PUBLISHED IN BRAZ. J. PHYS. The results of the evaluation of the Generalized Interacting Boson Model (GIBM) Hamiltonian in the framework of Restricted Dynamics Approach have been used in order to estimate the microscopical values for the parameters of two phenomenological collective models - the Bohr- Mottelson Model (BMM) and the standard Interacting Boson Model (IBM). The microscopically derived parameter values are calculated, using the effective MV-interaction potential parameter values obtained from the Strictly Restricted Dynamics Model (SRDM) energy calculations for light a-cluster type nuclei with 8 < A < 60, and compared with the phenomenological model parameter values obtained from the direct fit to the experimental level energies of the same nuclei. IFT - P.014/97 Orthogonalty Relations and Supercharacter Formulas of U(m\n) representations J. Alfaro1, R. Medina and L.F. Urrutia2 1 Facultad de Fisica, Universidad Catdlica de Chile, Casilla 306, Santiago 22, Chile 2 Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, C.U., Apartado Postal 70-543, 04510 Mexico, D.F. PUBLISHED IN J. MATH. PHYS. In this paper we obtain the orthogonality relations for the supergroup U{m\n), which are re- markably different from the ones of the U{N) case. We extend our results for ordinary representa- tions, obtained some time ago [1], to the case of complex conjugated and mixed representations. Our results are expressed in terms of the Young tableaux notation for irreducible representations. We use the supersymmetric Harish-Chandra-ltzykson-Zuber [2,3] integral and the character ex- pansion technique as mathematical tools for deriving these relations. As a byproduct we also obtain closed expressions for the supercharacters and dimensions of some particular irreducible U(m\n) representations. A new way of labeling the U{m\n) irreducible representations in terms of m + n numbers is proposed. Finally, as a corollary of our results, new identities among the dimensions of the irreducible representations of the unitary group U(N) are presented. [1] J. Alfaro, R. Medina, L.F. Urrutia, J. Phys. A: Math. Gen. 28 (1995) 4581. [2] J. Alfaro, R. Medina, L.F. Urrutia, J. Math. Phys. 36 (1995) 3085. 24 [3] T. Guhr, J. Math. Phys. 32 (1991) 336. I FT - P.015/97 Infrared Dynamics in (2+1) Dimensions J. L. Boldo, B. M. Pimentel and J. L. Tomazelli PUBLISHED IN CANADIAN JOURNAL OF PHYSICS In this work we study the asymptotic behavior of (2+l)-dimensional quantum elec- trody- namics in the infrared region. We show that an appropriate redefinition of the fermion current operator leads to an asymptotic evolution operator which contains a divergent Coulomb phase and a contribution of the electromagnetic field at large distances, factored from the evolution operator for free fields, and conclude that the modified scattering operator maps two spaces of coherent states of the electromagnetic field, as in the Kulish-Faddeev model for QED in four space-time dimensions. [1] P. Kulish and L. Faddeev, Teor. Mat. Fiz. 4 (1970) 153 [Theor. Math. Phys. 4 (1970) 745]. [2] T. Murota, Prog. Theor. Phys. 24 (1960) 1109. [3] B. M. Pimentel and J. L. Tomazelli, J. Phys. G 20 (1994) 845. IFT - P.016/97 Free Field Representation of Non-Abelian Toda Models J.F. Gomes, F.E. Mendonca da Silveira, A.H. Zimerman and G.M. Sotkov1 1 Universidade Estadual do Rio de Janeiro - UERJ, Departamento de Fisica Tedrica, Rua S. Francisco Xavier 524, SO.550-013, Rio de Janeiro, RJ We present two alternative bosonizations for a class of NA-Toda theories. The first one is based on the explicit form of the classical solutions and generalize the free field realization for Bi NA-Toda theory. The existence of a transformation mapping the NA-Toda models into certain abelian Toda allows us to construct the currents of the former in terms of the standard Wn currents and a new free field. This observation together with the known free field representation of the Wn currents provide us a new bosonization of the NA-Toda algebra. Examples concerning An, (n = 1,2,3) and two different Bo NA-Toda models are considered in detail. A preliminary discussion on the quantization of these models is also given [1]A. Bilal, Nucl. Phys. B422, (1994),258 [2]J.L. Gervais and M.V. Saveliev, Phys. Lett. B 286, (1992), 271 [3]E. Witten, Phys. Rev. D44,(1991),314 25 IFT - P.017/97 SU(2)q Symmetries of Non-Abelian Toda Theories J.F. Gomes, A.H. Zimerman and G.M. Sotkov1 1 Universidade Estadual do Rio de Janeiro - UERJ, Departamento de Física Teórica, Rua S. Francisco Xavier 524, 20.550-013, Rio de Janeiro, RJ We study the symmetries of a large class of conformai NA-Toda theories. The algebra of the chiral conserved currents are shown to correspond to the semiclassical limit of a new type of conformai algebras unifying the generalized parafermions and Wn currents.These are associative algebras with quadratic relations. The charges of the chiral and anti-chiral nonlocal currents do not commute and together with a 17(1) charge of topological nature span the SU(2)q affine algebra of level k = 0. Possible physical implications of these results are discussed. [1]G.M. Sotkov and M. Stanishkov, Nucl.phys. B356,(1991),245 [2JJ.L. Gervais and M.V. Saveliev, Phys. Lett. B 286, (1992), 271 [3]A.N. Leznov and M.V. Saveliev, Commun. math. Phys. 89,(1983),59 IFT - F.019/97 Application of Renormalization to Potential Scattering Carlos F. de Araújo, Jr., Lauro Tomio. Sadhan K. Adhikari and T. Frederico2 1 Departamento de Física, ITA, CTA, 12228-900 São José dos Campos, São Paulo, Brasil PUBLISHED IN J. OF PHYS. A A recently proposed renormalization scheme can be used to deal with nonrelativistic potential scattering exhibiting ultraviolet divergence in momentum space. A numerical application of this scheme is made in the case of potential scattering with r~2 divergence for small r, common in molecular and nuclear physics, by the use of cut-offs in momentum and configuration spaces. The cut-off is finally removed in terms of a physical observable and model-independent result is obtained at low energies. The expected variation of the off-shell behavior of the t matrix arising from the renormalization scheme is also discussed. IFT - P.020/97 Linearizability of the Perturbed Burgers Equation R. A. Kraenkel. J. G. Pereira and E. C. de Rey Neto 26 We show in this report that the perturbed Burgers equation is equivalent, through a near- identity transformation and up to O(e), to a linearizable equation, if a certain condition is met. In the case the condition is not fullfilled, a normal form for the equation is given. IFT - P.021/97 Can BCS and BEC be synthesized? V.C.Aguilera-Navarro, M. Casas1, N. J. Davidson2, S. Fujita3, M. G. Lopes4, M. de Llano4, R. M. Quick2, A. Rigo1, 0. Rojo5, M. A. Soli's6, and A. A. Valadares4 1 Departament de Fisica - Universitat de les Illes Balears 2 Department of Physics - University of Pretoria 3Department of Physics - SUNNY - Buffalo 4Instituto de Investigaciones en Materiales - UN AM 5PESTIC, Secretaria Academica - IPN, Mexico eInstituto de Fisica - UN AM To appear in Condensed-Matter Theories, vol. 12 (Nova Science, NY-1997) The superconducting phase is widely believed to be a kind of Bose condensate. Transition temperatures that are substantially higher than BCS Tc values for a many-fermion system interact- ing pairwise via the familiar BCS interaction model indeed follow from Bose-Einstein condensation (BEC) in either a pure gas of "bosonic" Cooper pairs or in a mixture of the latter plus background fermions when pair-breaking effects are explicitly allowed. Such effects can arise when the pairs either move too fast or are thermally excited. Cooper pairs of definite center-of-mass momentum (CMM) but not definite relative momentum are "bosonic" even though they do not obey the usual Bose commutation relations, since they exhibit indefinite maximum occupation in a given state and thus obey the Bose-Einstein distribution. [1] S. Fujita and S. Godoy, Quantum Statistical Theory of Superconductivity (Plenum, IM. Y.) (in press). [2] Y. J. Uemura et al., Nature 352, 605 (1991); Phys. Rev. Lett. 66, 2665 (1991); Y. J. Uemura and G. M. Luke, Physica B 186-188, 223 (1993). [3] V. C. Aguilera-Navarro et al., Superconductivity as Bose-Einstein condensation in any positive dimension: A survey, in Topics in Theoretical Physics, (IFT, Sao Paulo, 1995) IFT - F.022/97 Short Distance QCD Contribution to the Electroweak Mass Difference of Pions A. A. Natale PUBLISHED IN PHYSICAL REVIEW D 27 It is known that the short distance QCD contribution to the mass difference of pions is quadratic on the quark masses, and irrelevant with respect to the long distance part [1]. It is also considered in the literature that its calculation contains infinities, which should be absorbed by the quark mass renormalization [2]. Following a prescription by Craigie, Narison and Riazuddin [3], of a renormalization group improved perturbation theory do deal with the electromagnetic mass shift problem in QCD, we show that the short distance QCD contribution to the electroweak pion mass difference (with mu = m,d ^ 0) is finite and, of course, its value is negligible compared to other contributions. [1] J. F. Donoghue and A. F. Perez, hep-ph/9611331. [2] B. Machet and A. A. Natale, Ann. Phys. (NY) 160, 114 (1985). [3] N. S. Craigie, S. Narison and Riazuddin, Nucl. Phys. B174, 207 (1980). IFT - P.023/97 Preliminaries to quantum field theory in curved spacetimes A.C.C. Guimaraes, G.E.A. Matsas and D.A.T. Vanzella We discuss the influence of the background thermal bath on the depolarization of electrons in high-energy storage rings, and on the photon emission associated with the spin flip. We focus, in particular, on electrons at LEP. Although the typical photon energy present in the background thermal bath is considerably smaller than the typical energy necessary to depolarize an electron at LEP, we show that in a certain interval of solid angles the photon emission is enhanced by several orders of magnitude because of the presence of the thermal bath. Notwithstanding, the overall depolarization induced by the background thermal bath at LEP conditions is much smaller than the one induced by plain acceleration at zero-temperature and can be neglected in practical situations. Eventually we discuss in what conditions the background thermal bath can enhance the overall depolarization by several orders of magnitude. IFT - P.024/97 Bounds on Contact Interactions from LEP1 Data and the High-Q2 HERA Events M. C. Gonzalez-Garcia1 and S. F. Novaes 1 Instituto de Fisica Corpuscular - IFIC/CSIC Dept. de Fisica Teorica, Universidad de Valencia 46100 Burjassot, Valencia, Spain PUBLISHED IN PHYSICS LETTERS B 28 A contact four-fermion interaction between light quarks and electrons has been evoked as a possible explanation for the excess of events observed by HERA at high—Q2- We explore the 1-loop effects of such interaction in T(Z° -» e+e~) measured at LEP and impose strong bounds on the lower limit of the effective scale. Our results are able to discard some of the contact interactions as possible explanation for the HERA events. [1] C. Adloff et al., HI Collaboration, report DESY 97-24 (1997), and hep-ex/9702012. [2] J. Breitweg et al, ZEUS Collaboration, report DESY 97-25 (1997), and hep-ex/9702015. [3] G. Altarelli et al, report CERN-TH/97-40, and hep-ph/9703276. IFT - P.025/97 Anomalous Couplings in e+e~ —»• W+W~'y at LEP2 and NLC F. de Campos, S. M. Lietti, S. F. Novaes and R. Rosenfeld PUBLISHED IN PHYSICAL REVIEW D We present sensitivity limits on the coefficients of a dimension-6 effective Lagrangian that parametrizes the possible effects of new physics beyond the Standard Model. Our results are based on the study of the process e+e~ —> W+W~j at LEP2 and NLC energies. In our calcu- lations, we include all the new anomalous interactions, involving vector and Higgs bosons, and take into account the Standard Model irreducible background. We analyse the impact of these new interactions on the total cross section, including the effects of electron beam and final W polarization. We then focus on operators that will not be constrained by the e+e~ —>• W+W~ process, obtaining limits based on the photon energy distribution. [1] K. Hagiwara, S. Ishihara, R. Szalapski and D. Zeppenfeld, Phys. Rev. D48, 2182 (1993). [2] S. M. Lietti, S. F. Novaes and R. Rosenfeld, Phys. Rev. D54, 3266 (1996). [3] F. de Campos, S. M. Lietti, S. F. Novaes and R. Rosenfeld, Phys. Lett. B389, 93 (1996). IFT - P.026/97 Covariant Field Theory for Self-Dual Strings Nathan Berkovits and Warren Siegel1 Inst. for Theoretical Physics, State Univ. of New York, Stony Brook, NY 11794-3840, EUA PUBLISHED IN NUCLEAR PHYSICS B We give a gauge and manifestly SO(2,2) covariant formulation of the field theory of the self- dual string. The string fields are gauge connections that turn the super-Virasoro generators into 29 covariant derivatives. [1] H. Ooguri and C. Vafa, Nucl. Phys. B367 (1991) 83. [2] N. Berkovits, Nucl. Phys. B450 (1995) 90. [3] G. Chalmers and W. Siegel, Phys. Rev. D54 (1996) 7628. I FT - P.027/97 A Simple Prescription for Computing the Stress-energy Tensor A. J. Accioly, A D Azeredo, C M L de Aragao1, H.Mukai2 1 Institute de Fisica, Universidade de Sao Paulo, C.P. 20516, 01452-900 Sao Paulo, SP, Brazil 2 Departamento de Fisica, Fundagdo Universidade Estadual de Maringd, Av. Colombo 5790, 87020-900, Maringd, Pr, Brazil PUBLISHED IN CLASSICAL AND QUANTUM GRAVITY A non-variational technique for computing the stress-energy tensor is presented. The prescription is used, among other things, to obtain the correct field equations for Prasanna's highly nonlinear electrodynamics. (Prasanna A R 1973 Lett. Nuovo Cimento 6 420 ) [1] Accioly A J and Wichoski U F 1900 Class. Quantum Grav. 7 L139 [2] Accioly A J, Wichoski U F, Kwok S F and Pereira da Silva N L P 1993 Class. Quantum Grav. 10 L215; Accioly A J, Spehler D, Novaes S F, Kwok S F and Mukai H 1995 Phys. Rev. D 51 931; Accioly A J, Aldrovandi R, Novaes S F, Spehler D and Mukai H 1997 Prog. Theor. Phys 97, N 1, 121. [3] Accioly A J, Wichoski U F and Bertarello N 1993 Braz. J. Phys. 23 392. I FT - P.028/97 Discriminating New Physics Scenarios at NLC: The Role of Polarization E. M. Gregores, M. C. Gonzalez-Garcia1 and S. F. Novaes 1 Institute de. Fisica Corpuscular - IFIC/CSIC Dept. de Fisica Teorica, Universidad de Valencia 30 46100 Burjassot, Valencia, Spain PUBLISHED IN PHYSICAL REVIEW D We analyze the capability of the next generation of linear electron-positron colliders (I\ILC), operating in the [1] K. Hagiwara, S. Komamiya and D. Zeppenfeld, Z. Phys. C29, 115 (1985). [2] O. J. P. Eboli, E. M. Gregores, J. C. Montero, S. F. Novaes and D. Spehler, Phys. Rev. D53, 1253 (1996). IFT - P.029/97 Q-DEFORMED FERMIONIC LIPKIN MODEL AT FINITE TEMPERATURE P. Galetti, B. M. Pimentel. C. L. Lima1 and J. T. Lunardi2 Mnstituto de Ffsica, Universidade de Sao Paulo 2Departamento de Matematica e Estati'stica, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR PUBLISHED IN PHYSICA A The interplay between temperature and q-deformation in the phase transition properties of many-body systems is studied in the particular framework of the collective g-deformed fermionic Lipkin model. It is shown that in phase transitions occuring in many-fermion systems described' by /n(2)g- like models are strongly influenced by the ^-deformation. [1] D. Galetti and B. M. Pimentel, An. Acad. Bras. Ci. 67 (1995) 7. [2] H. J. Lipkin, N. Meshkov and A. J. Glick, Nucl. Phys. 62 (1965) 188. [3] S. S. Avancini et al., J. Phys. A : Math. Gen. 28 (1995) 4915. TFT - P.030/97 Pasti-Sorokin-Tonin Actions in the Presence of Sources R. Medina, N. Berkovits. PUBLISHED IN PHYSICAL REVIEW D 31 Pasti, Sorokin and Tonin have recently constructed manifestly Lorentz-invariant actions for self-dual fied strengths and for Maxwell fields with manifest electromagnetic duality. Using the method of Deser, Gomberoff, Henneaux and Teitelboim, we generalize these actions in the pres- ence of sources. [1] P. Pasti, D. Sorokin and M. Tonin, "On Lorentz invariant actions for chiral P-forms", hep-th 9611100. [2] S. Deser, A. Gomberoff, M. Henneaux and C. Teitelboim, "Duality, self-duality, sources and charge quantization in abelian l\l-form theories", hep-th 9702184. [3] P. Pasti, D. Sorokin and M. Tonin, Phys. Rev. D52 (1995), 4277. IFT - P.031/97 First-Order Perturbed KdV Solitons R.A. Kraenkel To APPEAR IN PHYSICAL REVIEW E We consider the Korteweg-de Vries equation with a perturbation arising naturally in many physical situations. Although being asymptotically integrable, we show that the corresponding perturbed solitons do not have the usual scattering properties. Specifically, we show that there is a solution, correct up to O(e), where e is the perturbative parameter, consisting, at t —> — oo, of two superposed deformed solitons characterized by wave-numbers ki and k [1] A. S. Fokas and Q. M. Liu, Phys. Rev. Lett. 77, 2347 (1996). IFT - P.032/97 Energy and Momentum for the Electromagnetic Field Described by Three Outstanding Electrodynamics Antonio Accioly PUBLISHED IN AMERICAN JOURNAL PHYSICS A prescription for computing the symmetric energy-momentum tensor from.the field equations is presented. The method is then used to obtain the total energy and momentum for the electro- 32 magnetic field described by Maxwell electrodynamics, Born-lnfeld nonlinear electrodynamics and Podolsky generalized electrodynamics, respectively. [1] A. 0. Barut, Electrodynamics and Classical Theory of Fields and Particles (Dover Publica- tions, New York, 1980). See, also, references therein. J. D. Jackson, Classical Electrodynamics (John Wiley & Sons, 1975), second edition. [2] M. Born and L Infeld, "Foundations of the New Field Theory", Proc. Roy. Soc. A144, 68-71, (1942). [3] Boris Podolsky, "A Generalized Electrodynamics Part I - Non-Quantum", Phys. Rev. 62, 68-71, (1942). IFT - P.033/97 Extra Dimensions in Superstring Theory Nathan Berkovits PUBLISHED IN NUCLEAR PHYSICS B It was earlier shown that an SO(9,1) 9a spinor variable can be constructed from RNS matter and ghost fields. 8a has a bosonic worldsheet super-partner AQ which plays the role of a twistor variable, satisfying AI^A = pzX^ + i9Y^pz9 For Type 11A superstrings, the left-moving 0g, Ag A A and right-moving #/jQ, A#Q can be combined into 32-component SO(10,1) spinors 6 , \ . A l B This suggests that \ T ^BX = 2A"A#a can be interpreted as momentum in the eleventh direction. Evidence for this interpretation comes from the zero-momentum vertex operators of the Type IIA superstring, and from consideration of D-branes. As in the work of Bars, one finds an SO(10,2) structure for the Type IIA superstring and an SO(9,1) x SO(2,1) structure for the Type IIB superstring. [1] C. Hull and P.K. Townsend, Nucl. Phys. B438 (1995) 109. [2] N. Berkovits, Nucl. Phys. B379 (1992) 96. [3] N. Berkovits, Nucl. Phys. B420 (1994) 332. IFT - P.034/97^ Limits on Anomalous Top Couplings from Z Pole Physics 0. J. P. Eboli1, M. C. Gonzalez-Garcia2. and S. F. Novaes 1 Instituto de Ffsica, Universidade de Sao Paulo, Sao Paulo, SP, Brazil. 33 2 Instituto de Ffsica Corpuscular - IFIC/CSIC, Departament de Ffsica Teorica, Universitat de Valencia, Spain PUBLISHED IN PHYSICS LETTERS B We obtain constraints on possible anomalous interactions of the top quark with the elec- troweak vector bosons arising from the precision measurements at the Z pole. In the framework of SU(2)L <8> U(l)y chiral Lagrangians, we examine all effective CP-conserving operators of di- mension five which induce scalar and tensor currents involving the top quark. We constrained the magnitudes of these anomalous operators by evaluating their one-loop corrections to the Z pole physics. Our analysis shows that operators which break the SU{2)c custodial symmetry or modify the Zbb vertex are more strongly bounded. [1] R. D. Peccei and X. Zhang, Nud. Phys. B337, 269 (1990). [2] E. Malkawi and C. P. Yuan, Phys. Rev. D 50, 4442 (1994). [3] G. Altarelli, preprint CERN-TH/96-265 (hep-ph/9611239). I FT - P.035/97 On Closed Einstein-de Sitter Universes Helio V. Fagundes and Evelise Gausmann SUBMITTED TO PHYSICAL REVIEW LETTERS We briefly summarize the idea of cosmological model with compact, flat spatial sections. It has been suggested that, because of the COBE satellite's maps of the microwave background, such models cannot be small in the sense of Ellis, and hence are no longer interesting. Here we use Lehoucq et al.'s method of cosmic crystallography to show that these models are physically meaningful even if the size of the spatial sections is of the same order of magnitude as the radius of the observable horizon. I FT - F.036/97 Infrared finite solutions for the gluon propagator and the QCD vacuum energy J. C. Montero, A. A. Natale and P. S. Rodrigues da Silva Instituto de Fi'sica Teorica, Universidade Estadual Paulista Rua Pamplona, 145, 01405-900, Sao Paulo, SP - Brazil PUBLISHED IN PHYS. LETT. B 34 IMonperturbative infrared finite solutions for the gluon polarization tensor have been found, and the possibility that gluons may have a dynamically generated mass is supported by recent Monte Carlo simulation on the lattice. These solutions differ among themselves, due to different approximations performed when solving the Schwinger-Dyson equations for the gluon polarization tensor. Only approximations that minimize energy are meaningful, and, according to this, we compute an effective potential for composite operators as a function of these solutions in order to distinguish which one is selected by the vacuum. IFT- P.037/97 Causal Approach to Quantum Electrodynamics in Three-dimensional Space-time B. M. Pimentel. J. L. Tomazelli and W. F. Wreszinski1 1 Instituto de Fisica, Universidade de Sao Paulo We study the dinamically generated photon mass, the electron self-energy and the vertex in the causal theory of quantum electrodynamics in three-dimensional space-time QED3. We also provide a general discussion of the regulariza- tion and the gauge (in)dependence of the photon mass. The last section is devo- ted to challenging open problems. [1] G. Scharf, W. F. Wreszinski, B. M. Pimentel and J. L. Tomazelli, Ann. Phys. 231 185 (1994). [2] B. M. Pimentel and J. L. Tomazelli, Prog. Theor. Phys. 95 1217 (1996). [3] J. L. Boldo, B. M. Pimentel and J. L. Tomazelli, to appear inlntj. Theor. Phys. (1997). IFT - P.038/97 Ramond-Ramond Central Charges in the Supersymmetry Algebra of the Superstring Nathan Berkovits PUBLISHED IN PHYSICAL REVIEW LETTERS The free action for the massless sector of the Type II superstring was recently constructed using closed RIMS superstring field theory. The supersymmetry transformations of this action are shown to satisfy an N—2 D=10 SUSY algebra with Ramond-Ramond central charges. [1] J. Polchinski, Phys. Rev. Lett. 75 (1995) 4724. [2] N. Berkovits, Phys. Lett. B395 (1997) 28. [3] N. Berkovits, Phys. Lett. B388 (1996) 743. 35 IFT - P.039/97 Are Two Gluons the QCD Pomeron? 0. J. P. Eboli1, E. M, Gregores and F. Halzen2 1 Institute) de Fisica, Universidade de Sao Paulo 2 Department of Physics, University of Wisconsin Collider experiments have recently measured the production cross section of hard jets sepa- rated by a rapidity gap as a function of energy and transverse momentum. We show that these measurements reveal the relative frequencies for the production of rapidity gaps in quark-quark, quark-gluon and gluon-gluon interactions. The results are at variance with the idea that the exchange of 2 gluons is a first order approximation for the mechanism producing colorless states, i.e the hard QCD Pomeron. They do qualitatively support the "soft color" or "color evaporation" scheme developed in the context of bound-state heavy quark production. [1] DO Collaboration, S. Abachi, et al, preprint FERMILAB-PUB-95/302-E; J. Perkins, talk given at the Madison Phenomenology Symposium, Madison, 1997. [2] J. Amundson, 0. Eboli, E. Gregores, and F. Halzen, Phys.Lett. B372, 127 (1996). [3] 0. Eboli, E. Gregores, and F. Halzen, Proceedings of the 26th International Symposium on Multiparticle Dynamics (ISMD96), Faro, Portugal, 1996. IFT - P.040/97 An Introduction to Superstring Theory and its Duality Symmetries Nathan Berkovits In these proceedings for the First School on Field Theory and Gravitation (Vitoria, Brasil), a brief introduction is given to superstring theory and its duality symmetries. This introduction is intended for beginning graduate students with no prior knowledge of string theory. [1] P. Townsend, hep-th 9612121. [2] J. Polchinski, hep-th 9611050. [3] H. Ooguri, hep-th 9612254. IFT - P.041/97 Renormalization in Nonrelativistic Quantum Scattering 36 Sadhan K. Adhikari and Angsula Ghosh PUBLISHED IN JOURNAL OF PHYSICS A The importance and usefulness of renormalization are emphasized in nonrelativistic quantum mechanics. The momentum space treatment of both two-body bound state and scattering prob- lems involving some potentials singular at the origin exhibits ultraviolet divergence. The use of renormalization techniques in these problems leads to finite converged results for both the ex- act and perturbative solutions. The renormalization procedure is carried out for the quantum two-body problem in different partial waves for a minimal potential possessing only the threshold behavior and no form factors. The renormalized perturbative and exact solutions for this problem are found to be consistent with each other. The useful role of the renormalization group equations for this problem is also pointed out. IFT - P.042/97 The electromagnetic gauge invariance in SU(3)L <8> U(1)N models of electroweak unification reexamined V. Pleitez. M. D. Tonasse x 1 Institute de Fisica da Universidade do Estado do Rio de Janeiro, Rua Sao Francisco Xavier 524, 20550-013, Rio de Janeiro, RJ Submitted to PHYSICS LETTERS B Two models with SU(3)C®SU(3)L®U(1)N gauge symmetry are considered. We show that the masslessness of the photon does not prevent the neutrinos from acquiring Majorana masses. That is, there is no relation between the VEVs of Higgs fields and the electromagnetic gauge invariance contrary to what has been claimed recently. [1] J. C. Montero, F. Pisano and V. Pleitez, Phys. Rev. D 47 2918 (1993). [2] M. Ozer, Phys. Lett. B 337, 324 (1994). [3] F. Pisano, J.A. Silva-Sobrinho and M. D. Tonasse, Phys. Lett. B 388, 338 (1996) 338. IFT - P.043/97 Flavor chiral extensions for the standard model F. Pisano. V. Pleitez e M. D. Tonasse l 1 Instituto de Fisica sa Universidade do Estado do Rio de Janeiro, Rua Sao Francisco Xavier 524, 20550-013-Rio de Janeiro, RJ, Brasil 37 We review several extensions of the standard SU(2)i ® U(l)y model based on SU(3)c ® SU(Z)L ® U(1)N gauge symmetry (3-3-1 models). This kind of models are anomaly free only if there are equal number of triplets and antitriplets, counting the color of SU(S)c- It implies that the family number must be divisible by three. Some interesting features arise in the context of these models which do not come up in the standard model. They predict new kind of particles like scalar and vector bilepton with 0, ±1, ±2 electric charge and new sources of CP violation in the leptonic and quark sector. We also briefly consider the extension SU(3)c ® SU(4)L ® U(l) and n-m-1 extensions. Left-right symmetric models, horizontal symmetries and one SU(6) grand unified theory are briefly considered. [1] F. Pisano e V. Pleitez, Phys. Rev. D 46, 410 (1992); R. Foot, 0. F. Hernandez, F. Pisano e V. Pleitez, Phys. Rev. D 47, 4158(1993). [2] F. Pisano, J. C. Montero e V. Pleitez, Phys. Rev. D 47, 2918 (1993). [3] V. Pleitez e M. D. Tonasse, Phys. Rev. D 48, 5274 (1993). IFT - P.044/97 Tunneling Through a Barrier V. C. Aguilera-Navarro1, V. M. Aquino1 M. Goto1 and H. Iwamoto l 1 Departamento de Ffsica - CCE - UEL, Londrina, PR SUBMITTED TO PHYSICAL REVIEW A The problem of a quantum particle incident on a rectangular barrier potential is discussed using the stationary phase method. The time evolution of a wave packet highly concentrated in the vicinity of a given kbara less than ko, the height of the barrier measured in wavenumbers, is discussed. In this context, the centers of the different wave pakets are discussed in the three potential regions. Particular emphasis is given to the potential region where a detailed analysis is carried out. [1] R. Landauer and Th. Martin, Rev. Mod. Phys. 66, 217 (1994) [2] T. E. Hartman, J. Appl. Phys. 33, 3427 (1962) [3] M. Buttiker and R. Landauer, Phys. Rev. Lett. 49, 1739 (1982) IFT - P.045/97 Limits on WW7 Coupling from Higgs Boson Production at the Tevatron Collider F. de Campos, M. C. Gonzalez-Garcia1, and S. F. Novaes 38 1 Institute) de Fisica Corpuscular - IFIC/CSIC, Departament de Fisica Tedrica Universitat de Valencia, 46100 Burjassot, Valencia, Spain PUBLISHED IN PHYSICAL REVIEW LETTERS We obtain tight limits on possible WWj anomalous couplings from the analysis of Higgs boson phenomenology under a naturalness assumption on the coefficients of effective operators. Our bounds, based on the data sample already collected by the collaborations at Fermilab Tevatron, are more restrictive than the expected limits from LEP II or even from the upgraded Tevatron collider. The coefficients of pure Higgs-vector boson couplings are also determined with unprecedented accuracy. [1] K. Hagiwara, S. Ishihara, R. Szalapski and D. Zeppenfeld, Phys. Lett. B283, 353 (1992); idem, Phys. Rev. D48, 2182 (1993); K. Hagiwara, T. Hatsukano, S. Ishihara and R. Szalapski, Nucl. Phys. B496, 66 (1997). [2] S. Abachi et al., D0Collaboration, Phys. Rev. Lett. 78, 3634 (1997). [3] Amidei et al., Future Electroweak Physics at the Fermilab Tevatron: Report of the TeV- 2000 Study Group, preprint FERMILAB-PUB-96-082 (1996). I FT - P.046/97 Gravitational Lorentz Force and the Description of the Gravitational Interaction V. C. de Andrade and J. G. Pereira PUBLISHED IN PHYS. REV. D In the context of a gauge theory for the translation group, we have obtained, for a spinless particle, a gravitational analog of the Lorentz force. Then, we have shown that this force equation can be rewritten in terms of magnitudes related to either the teleparallel or the riemannian structures induced in spacetime by the presence of the gravitational field. In the first case, it gives a force equation, with torsion playing the role of force. In the second, it gives the usual geodesic equation of General Relativity. The main conclusion is that scalar matter is able to feel anyone of the above spacetime geometries, the teleparallel and the metric ones. Furthermore, both descriptions are found to be completely equivalent in the sense that they give the same physical trajectory for a spinless particle in a gravitational field. 39 [1] K. Hayashi and T. Shirafuji, Phys. Rev. D 19, 3524 (1979). [2] F. W. Hehl, J. D. McCrea, E. W. Mielke and Y. Ne'eman, Phys. Rep. 258, 1 (1995). [3] R. Weitzenbock, Invariantentheorie (Noordhoff, Gronningen, 1923). IFT - P.047/97 Triple Gauge Boson Production and Dynamical Symmetry Breaking at the Next Linear Colllider Rogerio Rosenfeld and Alfonso R. Zerwekh SUBMITTED TO PHYSICS LETTERS B We study in a model independent way the role of a techniomega resonance in the process e+e~ -» W+W~Z at the Next Linear Collider. [1] R. Rosenfeld and J. L. Rosner, Phys. Rev. D38, 1530 (1988) [2] E. Eichten and K. Lane, Phys. Lett. B388,803 (1996). IFT - P.048/97 New Higgs Interactions in ZZ'y and Z77 Production S. M. Lietti and S. F. IMovaes Institute de Fisica Teorica, Universidade Estadual Paulista, Rua Pamplona 145, CEP 01405-900 Sao Paulo, Brazil. SUBMITTED TO PHYS. LETT. B The effect of new operators that only modify the bosonic couplings of the Higgs boson, without altering the WW7 or WWZ three-point functions, are examined in the e+e~~ —> ZZ-y and Z77 processes. We analyse the constraints on these interactions that can be imposed by the LEP II collider at CERN and at the Next Linear Collider. [1] K. Hagiwara, T. Hatsukano, S. Ishihara and R. Szalapski, Nucl. Phys. B496, 66 (1997). [2] S. M. Lietti, S. F. Novaes and R. Rosenfeld, Phys. Rev. D54, 3266 (1996); F. de Campos, S. M. Lietti, S. F. Novaes and R. Rosenfeld, Phys. Lett. B389, 93 (1996). 40 IFT - P.049/97 Riemannian and Teleparallel Descriptions of the Scalar Field Gravitational Interaction V. C. de Andrade and J. G. Pereira To APPEAR IN GEN. REL. GRAV. A comparative study between the metric and the teleparallel descriptions of gravitation is made for the case of a scalar field. In contrast to the current belief that only spin matter could detect the teleparallel geometry, scalar matter being able to feel the metric geometry only, we show that a scalar field is able not only to feel anyone of these geometries, but also to produce torsion. Furthermore, both descriptions are found to be completely equivalent, which means that in fact, besides coupling to curvature, a scalar field couples also to torsion. [1] K. Hayashi and T. Shirafuji, Phys. Rev. D 19, 3524 (1979). [2] F. W. Hehl, J. D. McCrea, E. W. Mielke and Y. Ne'eman, Phys. Rep. 258, 1 (1995). [3] V. C. de Andrade and J. G. Pereira, Phys. Rev. D (1997), in press (gr-qc/9703059). IFT - P.050/97 Are High Energy Cosmic Rays Magnetic Monopoles ? CO. Escobar1'2, R.A. Vazquez2'3 1 Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, Brazil 2 Instituto de Fisica "Gleb Gataghim", Unicamp, Brazil 3 Instituto de Fisica Teorica, Unesp, Brazil SUBMITTED TO ASTROPARTICLE PHYSICS We argue that magnetic monopoles can not be associated to the highest energy cosmic rays as recently suggested. Both the observed spectrum and the arrival direction disagree with observation. [1] T.J. Weiler and T.K. Kephart, Nucl.Phys.Proc.SuppI 51 B (1996) 218. preprint astro- ph/9605156. [2] IM. Hayashida et al. Phys. Rev. Lett. 77 (1996) 1000. [3] T. Stanev, P.L. Biermann, J. Lloyd-Evans, J. Rachen and A.A. Watson, Phys. Rev. Lett. 75 41 (1995) 3056. IFT - P.051/97 Universal Aspects of Efimov States and Light Halo Nuclei A, E. A. Amorim 1>2, T. Frederico 3 Lauro Tomio x 1 Instituto de Física Teórica - UNESP, 01405-900, São Paulo, Brasil 2 Faculdade de Tecnologia de Jahu, CEETEPS, Jahu, Brasil 3 Dep. de Física, ITA, Centro Técnico Aeroespacial, 12228-900 São José dos Campos, Brasil PUBLISHED IN PHYS. REV. C, RAPID COMMUNICATIONS (1997) The parametric region in the plane defined by the ratios of the energies of the subsystems and the three body ground state, in which Efimov states can exist, is determined. We use a renormalizable model that guarantees the general validity of our results in the context of short range interactions. The experimental data for one and two-neutron separation energies, implies that among the halo-nuclei candidates, only 20C has a possible Efimov state, with an estimated energy less than 14 KeV below the scattering threshold. IFT - P.052/97 Fixed Points and Vacuum Energy of Dynamically Broken Gauge Theories A. A. Natale and P. S. Rodrigues da Silva Instituto de Física Teórica, Universidade Estadual Paulista Rua Pamplona, 145, 01405-900, São Paulo, SP - Brazil PUBLISHED IN MOD. PHYS. LETT. A We show that if a gauge theory with dynamical symmetry breaking has non-trivial fixed points, they will correspond to extrema of the vacuum energy. This relationship provides a different method to determine fixed points. 42 I FT - P.053/97 Solitons from Dressing in an Algebraic Approach to the Constrained KP Hierarchy LA. Ferreira, J.F. Gomes, A.H. Zimerman , A.H. Aratyn1 1 Department of Physics, University of Illinois at Chicago, 845 Taylor St. Chicago, II 60607-7059 The algebraic matrix hierarchy approach based on affine Lie algebras leads to a variety of 1+1 soliton equations. By varying the rank of the underlying algebra as well as its gradation in the affine setting, one encompasses the set of soliton equations of the constrained KP hierarchy. [1J H. Aratyn, L.A. Ferreira, JF. Gomes and A.H. Zimerman, J. Math. Phys. 38, 1997, 1559. [2] H. Aratyn, J.F. Gomes and A.H. Zimerman, J. Math. Phys. 36, 1995, 3419. [3] E. Witten, Phys. Rev. D44,(1991),314. I FT - P.054/97 Gravitational Waves from the Henon-Heiles System Fernando Kokubun To Appear in PHYS.REV.D In this work we analyze the emission of gravitational waves from the Henon-Heiles system. We show the qualitative differences among emission of the gravitational waves from regular and chaotic motions. IFT - P.055/97 Construction of R4 Terms in N=2 D—8 Superspace Nathan Berkovits Using linearized superfields, RA terms in the Type II superstring effective action compactified on T2 are constructed as integrals in N=2 D=8 superspace. The structure of these superspace integrals allows a simple proof of the R4 non-renormalization theorems which were first conjectured by Green and Gutperie. [1] M. Green and M. Gutperie, Nucl. Phys. B498 (1997) 195, hep-th 9701093. [2] N. Berkovits and W. Siegel, Nucl. Phys. B462 (1996) 213, hep-th 9510106. 43 [3] H. Ooguri and C. Vafa, Nucl. Phys. B451 (1995) 121, hep-th 9505183. I FT - P.056/97 On the dissimilarity between the algorithms for computing the symmetric energy-momentum tensor in ordinary field theory and general relativity A. Accioly and H.Mukai1 1 Departamento de Fisica, Fundagdo Universidade Estadual de Maringd, Av. Colombo 5790, 87020-900, Maringd, Pr, Brazil PUBLISHED IN THE NOTE BREVI SECTION OF IL NUOVO CIMENTO B The recipe used to compute the symmetric energy-momentum tensor in the framework of ordinary field theory bears little resemblance to that used in the context of general relativity, if any. We show that if one starts from the field equations instead of the Lagrangian density, one obtains a unified algorithm for computing the symmeric energy-momentum tensor in the sense that it can be used for both usual field theory and general relativity. [1] PODOLSKY B., Phys. Rev. 62 (1942) 68. [2] MANDL F. and Shaw G., Quantum Field Theory, (Wiley, 1984). [3] PRASANIMA A. R., Phys. Lett. A, 37 (1971) 331; Lett. Nuovo Cimento, 6 (1973) 420. I FT - P.057/97 First Massive State of the Superstring in Superspace Nathan Berkovits Marcelo M. Leite PUBLISHED IN PHYSICS LETTERS B Using the manifestly spacetime supersymmetric description of the four-dimensional open su- perstring, we construct the vertex operator in superspace for the first massive state. This con- struction provides an N=l D=4 superspace representation of the massive spin-2 multiplet. 44 [1] N. Berkovits, Nucl. PhysB450(1995) 90, hep-th/9503099. [2] N. Berkovits, Phys.Lett.B385(1996) 109, hep-th/9604120. [3] IM. Berkovits, "A New Description of the Superstring", proceedings of the VIII J. A. Swieca Summer School on Particles and Fields, World Scientific Publishing (1996), hep-th/9604123. IFT - P.058/97 Positron-Helium Scattering: Resonance and Differential Cross Sections Puspitapallab Choudhuri and Sadhan K. Adhikari To APPEAR IN NUCLEAR PHYSICS A We study positron-helium scattering using close coupling approximation (CCA) employing dif- ferent combinations of the following basis functions: He(lsls), He(ls2s), He(ls2p), Ps(ls), and Ps(2s), where Ps stands for the positronium atom. We observe a prominent S wave resonance of width 2 eV at about 30 eV, in excitation and rearrangement cross sections to He(ls2s), He(ls2p), Ps(ls) and Ps(2s) states. We also report results of differential cross sections for the excitation of helium and positronium formation. IFT - P.059/97 Aspects of classical and quantum motion on a flux cone Edisom S. Moreira Jnr. SUBMITTED TO COMMUN. MATH. PHYS. Motion of a non-relativistic particle on a cone with a magnetic flux running through the cone axis (a "flux cone") is studied. It is expressed as the motion of a particle moving on the Euclidean plane under the action of a velocity-dependent force. Probability fluid ("quantum flow") associated with a particular stationary state is studied close to the singularity, demonstrating non trivial Aharonov-Bohm effects. For example, it is shown that near the singularity quantum flow departs from classical flow. In the context of the hydrodynamical approach to quantum mechanics, quantum potential due to the conical singularity is determined and the way it affects quantum flow is analysed. It is shown that the winding number of classical orbits plays a role in the description of the quantum flow. Connectivity of the configuration space is also discussed. [1] S. Olariu and I. I. Popescu, Rev. Mod. Phys. 57, 339 (1985) [2] G. "t Hooft, Commun. Math. Phys. 117, 685 (1988) [3] S. Deser and R. Jackiw, Commun. Math. Phys. 118, 495 (1988) 45 IFT - P.060/97 Quantization Rules for Bound States in Quantum Wells M. A. F. Gomes1 and Sadhan K. Adhikari ^epartamento de Fi'sica, Universidade Federal de Pernambuco 50.670-901 Recife, Pernambuco, Brazil PUBLISHED IN JOURNAL OF PHYSICS B An algebraic reformulation of the Bohr-Sommerfeld (BS) quantization rule is suggested and applied to the study of bound states in one dimensional quantum wells. The energies obtained with the present quantization rule are compared to those obtained with the usual BS and WKB quantization rules and with the exact solution of the Schrodinger equation. We find that, in diverse cases of physical interest in molecular physics, the present quantization rule not only yields a good approximation to the exact solution of the Schrodinger equation, but yields more precise energies than those obtained with the usual BS and/or WKB quantization rules. Among the examples considered numerically are the Poeschl-Teller potential and several anharmonic oscillator potentials, which simulate molecular vibrational spectra and the problem of an isolated quantum well structure subject to an external electric field. IFT - P.061/97 Universal scaling in BCS superconductivity in three dimensions in non-s waves Angsula Ghosh and Sadhan K. Adhikari To APPEAR IN EUROPEAN PHYSICAL JOURNAL B The solutions of a renormalized BCS equation are studied in three space dimensions in s, p and d waves for finite-range separable potentials in the weak to medium coupling region. In the weak-coupling limit, the present BCS model yields a small coherence length £ and a large critical temperature, Tc, appropriate for some high-Tc materials. The BCS gap, Tc, £ and specific heat CS(TC) as a function of zero-temperature condensation energy are found to exhibit potential- independent universal scalings. The entropy, specific heat, spin susceptibility and penetration depth as a function of temperature exhibit universal scaling below Tc in p and d waves. 46 IFT - P.062/97 Differential Cross Sections for Target Excitation and Positronium Formation in Positron-Helium Scattering Puspitapallab Chaudhuri and Sadhan K. Adhikari To APPEAR IN PHYSICAL REVIEW A Positronium formation and target excitation in positron-helium scattering have been investi- gated using the close-coupling approximation with realistic wave functions for the positronium and helium atoms. The following eight states have been used in the close-coupling scheme: He(lsls), He(ls21s), He{ls2lp), He(ls31s), He(lsZlp), Ps(ls), Ps(2s), Ps(2p), where Ps stands for the positronium atom. Calculations are reported of differential cross sections for elastic scatering, inelastic target excitation to He(ls21s) and He(ls21p) states, and rearrangement transition to Ps(ls), Ps(2s), and Ps(2p) states for incident positron energies between 40 and 200 eV. The coincidence parameters for the transition to the He^^p) state of helium are also reported and briefly discussed. PACS Number(s): 34.90.+q, 34.40.+n IFT - P.063/97 Negative Dimensional Integration: "Lab Testing" at Two Loops Alfredo T. Suzuki and Alexandre G. M. Schmidt PUBLISHED IN JHEP Negative dimensional integration method (NDIM) is a technique to deal with D-dimensional Feynman loop integrals. Since most of the physical quantities in perturbative Quantum Field Theory (pQFT) require the ability of solving them, the quicker and easier the method to evaluate them the better. The NDIM is a novel and promising technique, ipso facto requiring that we put it to test in different contexts and situations and compare the results it yields with those that we already know by other well-established methods. It is in this perspective that we consider here the calculation of an on-shell two-loop three point function in a massless theory. Surprisingly this approach provides twelve non-trivial results in terms of double power series. More astonishing than this is the fact that we can show these twelve solutions to be different representations for the same well-known single result obtained via other methods. It really comes to us as a surprise that the solution for the particular integral we are dealing with is twelvefold degenerate. IFT - P.064/97 Ps-H Scattering using three state positronium close coupling approximation 47 Prabal K Sinha1, Puspitapallab Chaudhuri and A. S. Ghosh1 department of Theoretical Physics, Indian Association for the Cultivation of Science, Calcutta 700032,India To APPEAR IN JOURNAL OF PHYSICS B Positronium scattering off hydrogen target has been studied employing a three state positron- ium model close coupling approximation (CCA) with and without electron exchange. The elastic, excitation and quenching cross sections are reported at low and medium energies. The exchange effect is found to be significant at low energies. The ratio of quenching to the total cross sec- tion,the conversion ratio, approaches the value 0.25 with the increase of energy, as expected. I FT - P.065/97 Anomalous Higgs Couplings in Triple Gauge Boson Production at the NLC F. de Campos, S. M. Lietti, S. F. Novaes and R. Rosenfeld TO APPEAR IN THE PROCEEDINGS OF THE "ECFA/DESY STUDY ON PHYSICS AND DETECTORS FOR THE LINEAR COLLIDER" We present the sensitivity limits on the coefficients of a dimension-6 effective operators that parametrizes the possible effects of new physics beyond the Standard Model. Our results are based on the study of the processes e+e~ —> W+W~j, ZZj, and Z77 at NLC energies. In our calculations, we include all the anomalous interactions involving vector and Higgs bosons, and take into account the Standard Model irreducible background. We analyse the impact of these new interactions on the total cross section and on some kinematical distributions of the final state particles. [1] K. Hagiwara, S. Ishihara, R. Szalapski and D. Zeppenfeld, Phys. Rev. D48, 2182 (1993); K. Hagiwara, T. Hatsukano, S. Ishihara and R. Szalapski, Nucl. Phys. B496, 66 (1997). [2] F. de Campos, S. M. Lietti, S. F. Novaes and R. Rosenfeld, Phys. Rev. D56, 4384 (1997); S. M. Lietti and S. F. Novaes, preprint IFT-P.048/97, hep-ph/9708433, submitted for publication. IFT - P.066/97 A New Approach to Integrable Theories in any Dimension 48 Orlando Alvarez, Luiz A. Ferreira and J.Sanchez Guillen Dept. Of Physics, Univ. Miami, Coral Gables, USA Depto. Fisica Particulas, Univ. Santiago de Compostela, Spain The zero curvature representation for two dimensional integrable models is generalized to spacetimes of dimension d + 1 by the introduction of a cf-form connection. The new generalized zero curvature conditions can be used to represent the equations of motion of some relativistic invariant field theories of physical interest in 2 + 1 dimensions (BF theories, Chern-Simons, 2 + 1 gravity and the CP1 model) and 3 + 1 dimensions (self- dual Yang-Mills theory and the Bogomolny equations). Our approach leads to new methods of constructing conserved currents and solutions. In a submodel of the 2 + 1 dimensional CP1 model, we explicitly construct an infinite number of previously unknown nontrivial conserved currents. For each integer spin representation of sl(2) we construct 2j + 1 conserved currents. IFT - P.067/97 Universal scaling in BCS superconductivity in two dimensions in non-s waves Sadhan K. Adhikari and Angsula Ghosh To APPEAR IN JOURNAL OF PHYSICS: COND. MATTER The solutions of a renormalized BCS model are studied in two space dimensions in s, p and d waves for finite-range separable potentials. The gap parameter, the critical temperature Tc, the coherence length £ and the jump in specific heat at Tc as a function of zero-temperature condensation energy exhibit universal scalings. In the weak-coupling limit, the present model yields a small ( and large Tc appropriate to those for high-Tc cuprates. The specific heat, penetration depth and thermal conductivity as a function of temperature show universal scaling in p and d waves. IFT - P.068/97 Vibrational-rotational analysis of the Hulthen potential using hydrogenic eigenfunction bases V.C.Aguilera-Navarro1 , E. Ley Koo2 and S. Mateos-Cortes2 1 Departamento de Fisica - CCE / UEL 2 Universidad Nacional Autonoma de Mexico Submitted to European Journal of Physics Hulthen's potential admits of analytical solutions for its energy eigenvalues and eigenfunctions correponding to zero angular momentum states, but its non-zero angular momentum states are 49 not equally known. This work presents a vibrational-rotational analysis of Hulthen's potential using hydrogenic eigenfunction bases. [1] L. Hulthen, Uber die Eigenlosungen der Schrodinger-Gleishung des Deuterons, Ark. Mat. Astron. Fys. 28A, 1 (1942). [2] C. S. Lai and W. C. Lin, Energies of the Hulthen Potential for £ ^ 0, Phys. Lett. 78A, 335 (1980). [3] R. Dutt and U. Mukherji, A New Analytic Approximation Method for the non-zero Angular Momentum States of the Hulthen Potential, Phys. Lett. 9OA, 395 (1982). I FT - P.069/97 On the Picture Dependence of Ramond-Ramond Cohomology Nathan Berkovits and Barton Zwiebach l 1 Center for Theoretical Physics and Departament of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA Closed string physical states are BRST cohomology classes computed on the space of states annihilated by b$. Since b$ does not commute with the operations of picture changing, BRST cohomologies at different pictures need not agree. We show explicitly that Ramond-Ramond (RR) zero-momentum physical states are inequivalent at different pictures, and prove that non- zero momentum physical states are equivalent at different pictures. We find that D-brane states represent BRST classes that are nonpolynomial in the superghost zero modes, while RR gauge fields appear as polynomial BRST classes. We also prove that in cc-cohomology, the cohomology where the zero mode of the spatial coordinates is included, there is a unique ghost-number one BRST class responsible for the Green-Schwarz anomaly, and a unique ghost number minus one BRST class associated with RR charge. [1] B. Zwiebach, Nuci. Phys. B390 (1993) 33, hep-th/9206084. [2] N. Berkovits, Phys. Rev. Lett. 79 (1997) 1813, hep-th/9706024. IFT - P.070/97 Duality-Symmetric Eleven-Dimensional Supergravity and its Coupling to M-Branes Igor Bandos x Nathan Berkovits Dmitri Sorokin 1 1 NSC, Kharkov Institute of Physics and Technology, Kharkov, 310108, Ukraine The standard eleven-dimensional supergravity action depends on a three-form gauge field and 50 does not allow direct coupling to five-branes. Using previously developed methods, we construct a covariant eleven-dimensional supergravity action depending on a three-form and six-form gauge field in a duality-symmetric manner. This action is coupled to both the M-theory two-brane and five-brane, and corresponding equations of motion are obtained. Consistent coupling relates D = 11 duality properties with self-duality properties of the M-5-brane. [1] E. Cremmer, B. Julia and J. Scherk, Phys. Lett. B76 (1978) 409. [2] N. Berkovits, Phys. Lett. B395 (1997) 28, hep-th/9610134. IFT - P.071/97 Vertex Operators and Solitons of Constrained KP Hierarchies L.A. Ferreira, J.F. Gomes, A.H. Zimerman , H. Aratyn1 1 Physics Department, University of Illinois at Chicago - USA We construct the vertex operator representation for the Affine Kac-Moody sl(M + K + 1) algebra, which is relevant for the construction of the soliton solutions of the constrained KP hierarchies. The oscillators involved in the vertex operator construction are provided by the Heisenberg subalgebras of sl(M + K + 1) realized in the unconventional gradations. The well- known limiting cases are the homogeneous Heisenberg subalgebra of sl(M) and the principal Heisenberg subalgebra of sl(K + 1). The explicit example of M = K = 1 is discussed in detail and the corresponding soliton solutions and tau-functions are given. [1] Aratyn, H., Gomes, J.F. and Zimerman, A.H. (1995): Journ. Math. Phys. 36 3419 [2] Aratyn, H., Ferreira, L.A., Gomes, J.F. and Zimerman, A.H. (1997): Jour. Math. Phys. 38 1559 [3] V.A. Fateev and A. Zamolodchikov, Nucl. Phys. B280,(1987),644 IFT - P.072/97 Manifestly Covariant Actions for D=4 Self-Dual Yang-Mills and D=10 Super-Yang-Mills Nathan Berkovits Chris Hull l 1 Physics Department, Queen Mary and Westfiled College, Mile End Road, London El 4NS, United Kingdom . 51 Using an infinite number of fields, we construct actions for D — 4 self-dual Yang-Mills with mani- fest Lorentz-covariance and for D = 10 super-Yang-Mills with manifest super-Poincare invariance. These actions are generalizations of the covariant action for the D = 2 chiral boson which was first studied by McClain, Wu, Yu and Wotzasek. [1] B. McClain, Y.S. Wu, and F. Yu, Nucl. Phys. B343 (1990) 689. [2] C. Wotzasek, Phys. Rev. Lett. 66 (1991) 129. [3] N. Berkovits, Phys. Lett. B395 (1997) 28, hep-th/9610134. IFT-P.073/97 Confronting Particle Emission Scenarios with Strangeness Data Frederique Grassi1'2 and Otavio Socolowski Jr. 1 Institute) de Fisica, USP, Brazil 2 Instituto de Fisica, Unicamp, Brazil To APPEAR IN PHYSICAL REVIEW LETTERS We show that a hadron gas model with continuous particle emission [1,2] instead of freeze out may solve some of the problems (high values of the freeze out density and specific net charge) that one encounters in the latter case when studying strange particle ratios such as those by WA85 [3]. This underlines the necessity to understand better particle emission in hydrodynamics to be able to analyze data. It also reopens the possibility of a quark-hadron transition occuring with phase equilibrium instead of explosively. [1] F. Grassi, Y. Hama and T. Kodama, Phys. Lett. B 355, 9 (1995). [2] F. Grassi, Y. Hama and T. Kodama, Z. Phys. C 73, 153 (1996). [3] S. Abatzis et al., Nucl. Phys. A 566, 225c (1994). IFT - P.074/97 Path integrals on a flux cone Edisom S. Moreira Jnr. SUBMITTED TO PHYS. REV. D This paper considers the Schrodinger propagator on a cone with the conical singularity carrying magnetic flux ("flux cone"). Starting from the operator formalism and then combining techniques 52 of path integration in polar coordinates and in spaces with constraints, the propagator and its path integral representation are derived. "Quantum correction" in the Lagrangian appears naturally and no a priori assumption is made about connectivity of the configuration space. [1] C. C. Bernido and A. inomata, J. Math. Phys. 22, 715 (1981) [2] G. "t Hooft, Commun. Math. Phys. 117, 685 (1988) [3] P. S. Gerbert, Nucl. Phys. B 346, 440 (1990) IFT - P.075/97 Minimal Supersymmetric Standard Model within CompHEP software package A.S.Belyaev1, A.V.Gladyshev2, A.V.Semenov3 1 Skobeltsin Institute for Nuclear Physics, Moscow State University, 119 899, Moscow, Russian Federation 2 Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141 980 Dubna, Moscow Region, Russian Federation 3 Laboratory of Particle Physics, Joint Institute for Nuclear Research, 141 980 Dubna, Moscow Region, Russian Federation SUBMITTED TO COMP. PHYS. COMMUN. The Minimal Supersymmetric Standard Model is presented as a model for the CompHEP software package as a set of files containing the complete Lagrangian of the MSSM, particle con- tents and parameters. All resources of CompHEP with a user-friendly interface are now available for the phenomenological study of the MSSM. Various special features of the model are discussed. [1] J. Rosiek, Phys. Rev. D41 (1990) 3464. [2] A. V. Gladyshev et al., Nucl. Phys. B498 (1997) 3, hep-ph/9603346. [3] E. E. Boos, M. N. Dubinin, V. A. llyin, A. E. Pukhov, V. I. Savrin, SNUTP-94-116, INP-MSU- 94-36/358. IFT - P.076/97 Search for Non-standard Higgs Boson in Diphoton Events at pp Collisions M. C. Gonzalez-Garcia1. S. M. Lietti and S. F. Novaes 1 Instituto de Fisica Corpuscular - IFIC/CSIC, Departament de Fisica Tedrica 53 Universitat de Valencia, 46100 Burjassot, Valencia, Spain SUBMITTED TO PHYSICAL REVIEW D We estimate the attainable limits on the coupling of a non-standard Higgs boson to two photons taking into account the data collected by the Fermilab collaborations on diphoton events. We based our analysis on a general set of dimension-6 effective operators that give rise to anomalous couplings in the bosonic sector of the Standard Model. If the coefficients of all "blind" operators are of the same order of magnitude, bounds on the anomalous triple vector- boson couplings can also be obtained. [1] S. Abachi et al, D0 Collaboration, Phys. Rev. Lett. 78, 2070 (1997). [2] C. J. C. Burguess and H. J. Schnitzer, Nucl. Phys. B228, 464 (1983); C. N. Leung, S. T. Love and S. Rao, Z. Phys. 31, 433 (1986); W. Buchmiillerand D. Wyler, Nucl. Phys. B268, 621 (1986) [3] K. Hagiwara, S. Ishihara, R. Szalapski and D. Zeppenfeld, Phys. Lett. B283, 353 (1992); idem, Phys. Rev. D48, 2182 (1993); K. Hagiwara, T. Hatsukano, S. Ishihara and R. Szalapski, Nucl. Phys. B496, 66 (1997). IFT - P.077/97 Testing the Resolving Power of 2-D K+K+ Interferometry Sandra S. Padula and Cristiane G. Roldao Adopting a procedure previously proposed to quantitatively study two-dimensional pion inter- ferometry[l], an equivalent 2-D %2 analysis was performed to test the resolving power of that method when applied to less favorable conditions, i.e., if no significant contribution from long lived resonances is expected, as in kaon interferometry. For that purpose, use is made of the preliminary E859 K+K+ interferometry data[2] from Si + Au collisions at 14.6 AGeV/c. As expected, less sensitivity is achieved in the present case, although it is shown that it is still possi- ble to distinguish two distinct decoupling geometries. As much as the previous result from pion interferometry, the preliminary kaon data seems to favor scenarios with no resonance formation at the AGS energy range. The possible compatibility of data with zero decoupling proper time interval, conjectured by the 3-D experimental anaylisis, is also investigated and seems to be ruled out when considering dynamical models with expanding sources. These results, however, clearly evidenciate the important influence of the time emission interval on the source effective transverse dimensions. [1] Sandra S. Padula and Miklos Gyulassy, Phys. Lett. 348 (1995) 303. [2] Y. Akiba et al., Phys. Rev. Lett. 70 (1993) 1057; V. Cianciolo, Ph.D Thesis presented to MIT (May/1994). 54 IFT - P.078/97 Two-loop self-energy diagrams worked out with NDIM Alfredo T. Suzuki and Alexandre G. M. Schmidt To APPEAR IN EUROPEAN PHYSICS JOURNAL C In this work we calculate two two-loop massless Feynman integrals pertaining to self-energy di- agrams using NDIM (Negative Dimensional Integration Method). We show that for arbitrary exponents of propagators and space-time dimension, the answer we get is 36-fold degenerate and then consider special cases of exponents for propagators and the outcoming results compared with known ones obtained via traditional methods. IFT - P.079/97 Tests of Anomalous Quartic Couplings at the NLC O. J. P. Eboli. M, C. Gonzalez-Garcia1 and J. K. Mizukoshi2 1 Institute) de Fisica Corpuscular - IFIC/CSIC, Departament de Fisica Teorica Universitat de Valencia, 46100 Burjassot, Valencia, Spain 2Instituto de Fisica , Universidade de Sao Paulo C. P. 66.318, 05315-970 - Sao Paulo, SP, Brazil. We analyze the potential of the Next Linear e+e Collider to study anomalous quartic vector- boson interactions through the processes e+e~ —» W+W~Z and ZZZ. In the framework of SU(2)L [1] T. Appelquist and C. Bernard, Phys. Rev. D22 (1980) 200; A. Longhitano, Phys. Rev. D22 (1980) 1166; Nucl. Phys. B188 (1981) 118. [2] J. Bagger, S. Dawson, and G. Valencia, Nucl. Phys. B399 (1993) 364. [3] G. Belanger and F. Boudjema, Phys. Lett. B288 (1992) 201. 55 U(1)Y chiral Lagrangians, we examine all effective operators of order p4 that lead to four-gauge-boson interactions but do not induce anomalous trilinear vertices. In our analysis, we took into account the decay of the vector bosons to fermions and obtained the efficiency in their reconstruction.