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Stephen Hawking with schoolchildren during the COSMO-97 international workshop on in Ambleside in the English Lake District. His public lecture 'The ' attracted a large audience.

Particle physics and the early

he spectacular progress of Tcosmology in recent years means that scientists have to face a dilemma. The comfort of an in­ creased understanding of the forma­ tion of a complex Universe in the has to be reconciled with an uncomfortable awareness that the Universe we actually see is only a small fraction of all there is. The search for this missing 'dark ' is the major goals of . will change in the years to come with model dependent and often difficult Theoretical and experimental experimentalists now seriously to analyse. Comprehensive reviews aspects of searches and involved in mapping the sky up to the by A. Linde (Stanford) and L. Kofman particle were the main largest distances. (Hawaii) summarized the present focus of the COSMO-97 international Much progress is expected in status. workshop on particle physics and the sharpening fine details of Some theorists boldly try to imagine early Universe. Held from 15-19 irregularities in the cosmic microwave what happened in the very first September 1997 in Ambleside in the background radiation and in deep sky moments of the Universe's history at beautiful English Lake District, the galaxy surveys. The emerging picture the ' scale' where the known meeting (organized by Lancaster of distribution around the laws of physics crumble. University) gathered some 110 Universe will have direct implications (with his participants from around the world. for predictions from inflationary student R. Bousso) Deciphering the script for the Big models and will be used as a model explored the consequences of his no- Bang was the main theme. discriminator, as reviewed by boundary approach, in particular the remains the only attractive J. Frieman (Fermilab), E. Kolb production and subsequent possible scenario for explaining the puzzle of (Fermilab) and D. Lyth (Lancaster). evaporation of primordial black holes. why the gross features of the cosmic Even present can constrain (A. Liddle of Sussex analysed how microwave background radiation look some cosmological scenarios. such objects would affect the the same in all directions. Inflation A. Albrecht reported that approaches subsequent evolution of the occurred as a brief period of ex­ in which large structures in the Universe.) tremely rapid expansion a tiny Universe have grown around Others advocate using superstring fraction of a second after the Big topological defects, like cosmic ideas to glimpse the evolution of the Bang. During this the Universe strings, are already inconsistent with Universe during the Planck era. stretched by over 40 orders of observations. At the end of inflation R. Brustein (Ben Gurion) presented magnitude and became nearly the Universe was very empty, cold, work with G. Veneziano (CERN) Euclidean in the process. This and dominated by an 'inflaton' which which addresses the issue of the beautiful idea introduced 15 years subsequently decayed to give the initial singularity in a so-called pre- ago by still lacks a fully particles we know . As a result Big-Bang approach. satisfactory particle physics scenario. the jumped up again Superstrings are often claimed to Understandably, this domain of and the Universe "reheated". be the theory of everything, but they research remains almost solely a While the general idea is easy to still lack understanding of their theoretical playground. However this sketch, the detailed theory is still fundamental structure. H.-P. Nilles

24 CERN Courier, January/February 1998 Physics monitor

Graham Ross of suggests a scenario with several periods of inflation of the early Universe.

(Munich) reviewed the presently sity, just enough to make the Uni­ much debated M(atrix)-theory which verse's expansion slow to zero at is supposed to shed a new on infinite time. While "direct" the theory of superstrings. He argued observations currently give the ratio that robust cosmological parameters, to be about one-third of the critical like the , can density, large-scale flows and cluster constrain certain otherwise allowed evolution tend to give higher values, predictions from strings. R. Gregory closer to whattheorists' favour, as (Durham) considered topological reviewed by J. Primack (Santa Cruz). defects resulting from superstrings. Measurements of the R. Kallosh (Stanford) reviewed a concentrations of light nuclei such as possible connection between black deuterium and helium in the Universe holes and superstrings. from the theory of nucleosynthesis Among the other topics discussed constrain the density of conventional relating to the particle physics of the matter (protons and neutrons) to be early Universe, J. Cline (McGill) about 5% of the critical density. argued that if the observed However, visible baryons in stars and asymmetry between baryons and galaxies account for less than 1%. antibaryons is to be explained by (Louisiana State), will soon be K. Freese (Michigan) argued that the purely (supersymmetric) electroweak challenged (or confirmed) by the "missing" baryons hide in very old effects, the mass of the Higgs KARMEN experiment at the UK stars - white dwarves. S. Raby (Ohio particle responsible for electroweak Rutherford Appleton Laboratory, State) presented another exotic symmetry breaking must be below according to J. Kleinfeller (RAL), possibility of coloured dark matter 100 GeV, making it accessible at while Chorus and Nomad at CERN, following currently hotly debated CERN's LEP electron-positron represented by J. Herin (Louvain), gauge-mediated SUSY-breaking collider. are not sensitive to the LSND signal. models. The origin and subsequent K. Zuber (Dortmund) reviewed the The other 95% of the total mass in evolution of primordial magnetic prospects for neutrino oscillation the Universe is probably non- fields, still poorly understood, were searches. Evidence for such mixing baryonic and locked in some yet discussed by K. Enqvist (Helsinki) of neutrino species from atmospheric undiscovered particles which only and M. Shaposhnikov (CERN). neutrino and solar neutrinos interact weakly. Such particles, G. Senjanovic (ICTP Trieste) observations is underlined by the known as WIMPs (Weakly Interacting showed how the normally expected Japanese Super-Kamiokande Massive Particles) should be restoration of symmetries at high detector (September 1997, page 25). abundant in the Galactic halo can be evaded in the The present picture remains surrounding us. One favourite bet is presence of non-zero charge unclear, with the LSND, solar and that these will be the lightest densities. This could automatically atmospheric data implying different supersymmetric particles (LSP). solve the domain and monopole oscillations, as reviewed by Many limits on the existence of problems in cosmology. D. Caldwell (Santa Barbara). He supersymmetric particles have come Another important theme of the argued that introducing a fourth, from LEP at CERN and the Tevatron workshop was cosmological relics of sterile neutrino would help solve the at Fermilab. Better limits, or a the Big Bang, where the subject is confusion. R. Mohapatra (Maryland) discovery, should come from the more experimental. Neutrino reviewed theoretical scenarios for LHC, as reviewed by S. Katsanevas oscillations would imply that neutrinos and conjectured that (Lyon) and V. Barger (Wisconsin). neutrinos have mass and hence may physics beyond conventional Grand J. Ellis (CERN) combined experimen­ contribute to dark matter. Unified Theories may be needed to tal data from LEP with cosmology to The first possible accelerator explain the data. sharpen the limits on the LSP. observation of neutrino oscillations Inflation in Big Bang cosmology R. Arnowitt (Texas A&M) and P. Nath from the Los Alamos LSND says that the Universe's mass (Northeastern) considered the WIMP experiment, presented by R. Imlay density is equal to the critical den­ in the context of supersymmetric

CERN Courier, January/February 1998 25 Physics monitor

The chairman of COSMO-97, L Roszkowski (left) with D. Caldwell who will be organizing the next COSMO meeting (COSMO-98) at Asilomar, California.

External correspondents

Argonne National Laboratory, (USA) D. Ayres

Brookhaven, National Laboratory, (USA) P. Yamin

CEBAF Laboratory, (USA) S. Corneliussen

Cornell University, (USA) D. G. Cassel

DESY Laboratory, (Germany) Ilka Flegel, P. Waloschek

Fermi National Accelerator Laboratory, unification. The of experiment at Stanford using an (USA) superpartners can be squeezed by innovative cryogenic technique. Judy Jackson collider searches from below, and An intriguing signal was claimed by GSI Darmstadt, (Germany) G. Siegert increasingly accurate cosmological D. Belli (INFN Rome) from the DAMA constraints from above. experiment with a heavily shielded INFN, (Italy) A. Pascolini Recent years have witnessed the sodium iodide crystal in the Italian Gran Sasso Laboratory. This IHEP, Beijing, (China) growth of an impressive experimental Qi Nading programme to hunt for WIMPs. An experiment sees a small annual JINR Dubna, (Russia) indirect way of searching for WIMP change in the putative WIMP count B. Starchenko signals is to look for energetic rate, corresponding to what would be KEK National Laboratory, (Japan) neutrinos from the (or the core of expected due to the earth's rotation A. Maki the Earth) from annihilation of WIMPs around the Sun and the Sun's motion Lawrence Berkeley Laboratory, (USA) gravitationally trapped there. F. through the Milky Way. If this is real, B. Feinberg Halzen (Wisconsin) reviewed such it will be confirmed soon by the UK Los Alamos National Laboratory, (USA) detection techniques and described Dark Matter collaboration running in C. Hoffmann the AMANDA project, a 1 km-cube the Boulby Mine in North-Eastern NIKHEF Laboratory, (Netherlands) neutrino telescope built into the ice at , described by T. Ali Margriet van der Heijden the South Pole. (Imperial, London), and by CDMS. Novosibirsk Institute, (Russia) S. Eidelman Direct searches look for a very faint One bold proposal was presented Orsay Laboratory, (France) energy deposit (a few by H.-V. Klapdor-Kleingrothaus Anne-Marie Lutz kiloelectronovolts) from WIMP whose Heidelberg group is designing PSI Laboratory, (Switzerland) scattering. Due to the extremely low the 1 tonne GENIUS germanium P.-R. Kettle rate expected, extreme detector (December, page 19). Rutherford Appleton Laboratory, (UK) sensitivity is required, along with COSMO-97 has initiated a series of Jacky Hutchinson careful shielding to reduce the "Lancaster workshops" which will be Saclay Laboratory, (France) background. Several detector held yearly: California will host Elisabeth Locci materials are used and experimental COSMO-98, COSMO-99 will return IHEP, Serpukhov, (Russia) techniques are improving, as to Europe and in 2000 the workshop Yu. Ryabov reviewed by N. Spooner (Sheffield). will be held in Korea. Stanford Linear Accelerator Center, (USA) M. Riordan More recently, extremely low temperature methods have been From Leszek Roszkowski and Terry TRIUMF Laboratory, (Canada) M. K. Craddock introduced to reduce heat noise. Sloan (Lancaster) They were reviewed by D. Bauer (Santa Barbara) from the CDMS

26 CERN Courier, January/February 1998 Faculty Position DEUTSCHES ELEKTRONEN Institute for SYNCHROTRON DESY State University of New York DESY is one of the leading laboratories in particle Stony Brook, N.Y. 11794-3840 physics and synchrotron radiation research. For its location in Zeuthen near DESY is offering a The Institute for Theoretical Physics at the State University of New York at Stony Brook will have an opening for a Full or POSTDOCTORAL RESEARCH POSITION Associate Professor beginning January, 1999. to young scientists to participate in the HERA-B experiment at HERA. The main goal of HERA-B is to study CP violation in decays of neutral The Institute does comprehensive research in various fields of B-mesons, one of the most interesting fields in modern elementary par­ theoretical physics including, but not limited to, gauge field ticle physics. theory, the standard model of elementary particles, perturbative To reduce the huge amount of data and to perform a pre-selection of events a multi-processor system (farm) with more than 100 nodes is quantum chromodynamics, lattice field theory, , currently under construction. superstrings and statistical mechanics, condensed matter physics. The accepted candidate is expected to work on concept, installation, It is also looking forward to expansion into mathematical and administration of a multi-processor farm for the date acquisition and biophysics. trigger system of the HERA-B experiment and on design and implemen­ tation of software for a distributed system. Furthermore, participation in the development of filter algorithms is possible. The position requires a Review of applications will begin on June 15, 1998 and conti­ high amount of motivation and reponsibility. nue until the position is filled. A doctoral degree in physics or computer science is required.

Applicants should submit a curriculum vitae, a summary of Applicants should be: current and proposed research and arrange to have three letters - able to administrate Unix-Systems on AlX-workstations and of recommendation sent to: especially Linux-PCs, - able to plan and install a network system based on standards, like Fast-Ethernet, email address: [email protected] - familiar with C, C++, and Fortran. „ - Knowledge of IP-programming is desirable. Professor Chen Ning Yang, Director or Experiences with high energy physics experiments is of advantage. Professor , Deputy Director, The position is limited to a duration of 3 years. The salary will be accord­ . SUNY - Institute for Theoretical Physics, ing to the German civil services BAT-O lia. Handicaped applicants will be given preferences to other applicants with Box A, the same qualification. Stony Brook, N.Y 11794-3840. DESY encourages especially women to apply. Interested young scientists should send their letter of application and The State University is an Equal Opportunity/Affirmative Action three names of referees and their addresses by February, 27th, 1998 to: employer. DESY Zeuthen, Personalabteilung Qualified women and minorities are encouraged to apply. Platanenallee 6,15738 Zeuthen, Tel.: 0049/33762/77210

The ISTITUTO NAZIONALE Dl FISICA NUCLEARE - Sezione di Pisa (Italy) is seeding an: On-Site Computer and Software System Manager

VIRGO is an Italian-French project of a large interferometer intended to detect gravitational waves. This interferometer is being built at Cascina near Pisa and involves about 150 researchers among 11 Italian and French laboratories. The first part is planned to be integrated early 1998 and full operation is foreseen in 2002. Job Description: on-site computer and software system manager. Functions: responsible for the on-site operation of the whole computer and software system of VIRGO. The selected candidate will actively participate to the initial on-site integration of the computer and software system and is expected to play a key-role in its subsequent and future development. Experience and education: the candidate will possess a University Degree in computer sciences or engineering or physics and a substantial experience in the operation of large and complex computer systems in a scientific environment. He/She will be well aware and will possess experience in modern software development methodologies. He/She will be fluent in English. Good knowledge of Italian and French will be an advantage. Working place: Cascina near Pisa (Italy). Contract: a 2 years contract will be offered with possibility of extension. The career path will be determined according to the experience and to the level of the functions performed. Candidates are invited to send a curriculum vitae in which is pointed out the respondence to the above requirements. Please send C.V. preferably within February 20, 1998 to the following address: Istituto Nazionale di Fisica Nucleare, Via Livornese n. 1291 - 56010 S. Piero a Grado (Pisa) Italy. Attn. Ms. Claudia Tofani. I.N.F.N, will get in touch with all screened candidates for an interview.

I.N.F.N, is now announcing that within a few months a notice of competition will be issued in order to seek the following position, for which advertisements will be published on Italian local and national newspapers. Job Description: electronics technician. Functions: assistant to the system manager for the operation and maintenance of the computer networks. He/She will also provide assistance for the computer system and electronics integration. Experience and education: the candidate will possess a technician degree in electronics or computer techniques and will have a few years of professional experience. He/She will have a good knowledge of English. Knowledge of French will be an advantage. Working place: Cascina near Pisa (Italy). Contract: a 2 years contract will be offered with possibility of extension. The career path will be determined according to the experience and to the level of the functions performed.

For any information: tel. (39) 50 880352 - fax (39) 50 880350 - e-mail: [email protected]

CERN Courier, January/February 1998 27