Sapienza Universit`adi Roma Dipartimento di Fisica Scientific Report 2007 - 2009 Sapienza Universit`adi Roma Dipartimento di Fisica Scientific Report 2007-2009 The Scientific Report has been edited by Daniele del Re, Marco De Petris, Leonardo Gualtieri, Fabio Sciarrino. Cover graphics by Fulvio Medici: Picture of Marconi Building Department of Physics Main Campus of Sapienza Universit`adi Roma Piazzale Aldo Moro 2, 00185 Roma In the 1930s, a group of young architects, directed by Marcello Piacentini, created the new University Campus of Rome. The building which currently hosts the Department of Physics was designed by Giuseppe Pagano (1896-1945) between 1932 and 1935. After the death of Guglielmo Marconi, in 1937, it was given the name Istituto Guglielmo Marconi. Originally Paganos building extended over 3400 square metres, and was divided into two main parts corresponding to Advanced Physics and Experimental Physics. It included workshops, a library and the guards houses. The two hundred and thirty-seven rooms that composed the building were organized following a functional scheme, related to the plant design and to the construction features of the building. The formal solutions, such as the mechanism of the windows, were defined with an aim to the maximal functionality; interior niches, colours, doors and windows were the same for all premises. The innovative conception and use of leading-edge techniques make this building a masterpiece of aesthetics and functionality, mentioned in various Architecture textbooks. Indeed, it had a profound influence on the other architects who worked at the University Campus. The building plan is the result of a free articulation of the various parts, according to the different functions that should be carried out, harmoniously incorporated as well-defined volumes to which the vacuum corresponds as an essential complement of rhythm. Guido Martinelli Sapienza Universit`adi Roma 2 Dipartimento di Fisica Scientific Report 2007-2009 Introduction Contents Introduction 5 In memory of Nicola Cabibbo 7 Personnel 9 Research areas and affiliations 14 List of research activities 15 Theoretical physics 19 Introduction . 19 Research activity . 24 Condensed matter physics and biophysics 47 Introduction . 47 Research activity . 54 Particle physics 101 Introduction . 101 Research activity . 108 Astronomy & Astrophysics 143 Introduction . 143 Research activity . 148 Geophysics 165 Introduction . 165 Research activity . 166 History of Physics and Physics Education 171 Introduction . 171 Research activity . 172 Laboratories and Facilities of the Department of Physics 175 Introduction . 175 Laboratories and Facilities . 176 Grants 201 Awards 207 Dissemination 209 Scientific Productivity . 209 Publications . 210 Theoretical Physics . 210 Condensed matter physics and biophysics . 216 Particle Physics . 231 Astronomy & Astrophysics . 247 Geophysics . 251 History of Physics and Physics Education . 253 Books ........................................................254 Organization of Schools, Workshops and Conferences . 255 Sapienza Universit`adi Roma 3 Dipartimento di Fisica Scientific Report 2007-2009 Introduction Sapienza Universit`adi Roma 4 Dipartimento di Fisica Scientific Report 2007-2009 Introduction Introduction The Department of Physics of `Sapienza', Universit`adi Roma, is the natural heir of the tradition of Enrico Fermi, Franco Rasetti, Ettore Majorana, Edoardo Amaldi, Bruno Pontecorvo, Emilio Segr`e(School of Rome), and is renown worldwide for its high quality research, international prestige and variety of teaching. In this report all the activities of the Department from 2007 to 2009 are presented. During these three years the scientists of the Department of Physics have published approximatively 1500 articles on international refereed journals. Many of these publications appeared on journals with the highest Impact Factor (IF): 60% of them on journals with impact factor greater than 3 and 15 appeared on journals with IF>10. The high quality of the research carried out in our Department has led to a large number of funding grants from Italian and European funding agencies. The scientific activity is organized in more than 100 research lines, grouped in six subject areas: Theoretical Physics, Condensed Matter Physics and Biophysics, Particle Physics, Astronomy & Astrophysics, Geophysics, History of Physics and Physics Education. For each area there is an introductive summary, followed by a one page report describing the main activities and lists of the involved scientists and the most relevant papers published in the considered time span. The detailed description of the Experimental and Computational Facilities of the Department is also included. To provide a complete insight on the Department activity, this book reports all the funded grants involving our institutions as well as Schools, Workshops and Conferences held in this period. The list of published papers in international referred journals divided by subject area and year completes the description. In the considered triennium several highly recognized awards have been granted to members of our community, let me just mention the most relevant: the Dirac Medal to Luciano Maiani, the Lagrange-CRT Foundation Prize and the Microsoft European Science Award to Giorgio Parisi, the Dan David Prize Astrophysics-History of the Universe to Paolo de Bernardis, the Boltzmann Medal to Giovanni Gallavotti, the Enrico Fermi Prize to Miguel Angel Virasoro and to Luciano Pietronero. Such a high rate of prizes received by scientists of the Department testifies that the "School of Rome" is still lively. The high quality of the research and educational activities of the Department draws the lifeblood of the commitment and passion of all members of the department itself. It is therefore both a pleasure and a duty to warmly thank all the administrative and technical staff, together with the whole body of scientists, for their personal effort to make things work. An effort that is more and more important in this very moment that sees a constant, dramatic reduction of resources, and the disownment of the value of research and culture. I would like to conclude this brief Introduction by dedicating this report to the memory of Nicola Cabibbo. We had the privilege of having Nicola as a member of our Department. His works on the weak interactions are worldwide recognized. He has also been the president of the Italian National Institute of Nuclear Physics from 1983 to 1992, president of ENEA from 1993 to 1998 and since 1993 he has been the president of the Pontifical Academy of Sciences. At the time of publication of this report he has been awarded the Dirac Medal, a prize that he cannot receive personally due to his untimely death. Giancarlo Ruocco Director of the Department of Physics Sapienza Universit`adi Roma 5 Dipartimento di Fisica Scientific Report 2007-2009 Introduction Sapienza Universit`adi Roma 6 Dipartimento di Fisica Scientific Report 2007-2009 Introduction In memory of Nicola Cabibbo On the 16th of August, Nicola Cabibbo, Professor of Theoretical Physics in our Department and one of the world leading particle physicists, passed away. At the beginning of his career, Cabibbo wrote with Raoul Gatto an exploratory paper on the physics that could be studied with e+e− interactions1, which soon became a standard reference in the field. In 1963, while at CERN, Cabibbo discov- ered a new fundamental constant of nature, named after him the Cabibbo angle2. In his theory, nuclear beta decay and strange par- ticle decays are included in a unified picture. Building on previous ideas by Fermi, Feyn- man and Gell-Mann and others, the Univer- sality concept thus formulated by Cabibbo opened the way to the Electroweak Unifica- tion, one of the highest achievements of mod- ern Physics. The success of his theory3 and his exceptional talent as teacher and confer- ence speaker made soon Cabibbo an interna- tionally known and influential figure. Professor in Roma since 1966, he has pro- moted a school of theoretical physicists which had a world recognized impact on the field of fundamental particles and interactions. Among the most important results: the par- ton description of e+e− annihilations into hadrons4, the computation of electroweak cor- rections to the muon magnetic moment5, the study of the beta decay of heavy quarks6, the prediction of the existence of a phase transi- tion from hadronic to deconfined quark-gluon matter7, the first lattice computation of weak parameters8, the study of upper and lower bounds to the Higgs boson mass in Grand Unified Theories9. Together with Giorgio Parisi, Cabibbo proposed and devised a parallel supercomputer dedicated to lattice QCD studies10. Nicola Cabibbo has been President of INFN (1983-1992), of ENEA (1993-1998) and of Ac- cademia Pontificia delle Scienze (since 1993). He was member of Accademia Nazionale dei Lincei and of the American Academy of Sciences. He received the High Energy and Particle Physics Prize of the European Physical Society (1991), the Sakurai Prize of the American Physical Soci- ety (1989) and the ICTP Dirac Medal (2010). Luciano Maiani President of CNR - Consiglio Nazionale delle Ricerche Sapienza Universit`adi Roma 7 Dipartimento di Fisica Scientific Report 2007-2009 Introduction 1. N. Cabibbo and R. Gatto, Electron-Positron Colliding Beam Experiments, Phys. Rev. 124, 1577 (1961). 2. N. Cabibbo, Unitary Symmetry and Leptonic Decays, Phys. Rev. Lett. 10, 531 (1963). 3. K. Nakamura et al. (Particle Data Group), J. Phys. G 37, 075021 (2010); N. Cabibbo, E. 4. C.Swallow and R. Winston, Semileptonic Hyperon Decays, Ann. Rev. Nucl. Part. Sci. 53, 39 (2003). 4. N. Cabibbo, G. Parisi and M. Testa, Hadron Production In e+ e- Collisions, Lett. Nuovo Cim. 4S1, 35 (1970). 5. G. Altarelli, N. Cabibbo and L. Maiani, The Drell-Hearn sum rule and the lepton magnetic moment in the Weinberg model of weak and electromagnetic interactions, Phys. Lett. B 40, 415 (1972). 6. G. Altarelli, N. Cabibbo and L. Maiani, Weak Nonleptonic Decays Of Charmed Hadrons, Phys. Lett. B 57, 277 (1975); G. Altarelli, N. Cabibbo, G. Corbo, L. Maiani and G. Martinelli, Leptonic Decay Of Heavy Flavors: A Theoretical Update, Nucl. Phys. B 208, 365 (1982). 7.