HEP-MAD '01

The following sections are included:

• PREFACE

• Picture

• Committee and Sponsors

• CONTENTS

The following sections are included:

• Traditional apology

• Opening address in French

• English translation of the original talk

We have used the embedded-atom method to perform molecular-dynamics simulations of iron films grown on the (111) copper surface. The iron atoms were randomly deposited, one at a time, above the surface just within the force range of the nearest surface atom. The growth mode is discussed by following the iron film coverage for an incident-atom energy ranging from 0.5 eV to 15 eV. A transition from island to layer-by-layer growth is observed as a function of incident energy. The effect of deposition rate is also studied.

Results of thermoluminescence personnel external monitoring are reported from 1990 to 2000 for workers in diagnostic radiology which represents more than 75% of the professional exposure in Madagascar and for which enough data for good statistical considerations are available. Average and individual doses distribution are presented. In most cases, compliance with dose limits is verified though some high exposures have been identified. Globaly, these doses can be compared with the average effective dose from natural radiation sources. Methods for the evaluation of quality and performance are presented as long as the doses measured are all in the low range.

In radiation protection, an important principle is to meet the requirements of the implementation of ALARA, in order to limit or reduce exposures. This work can be used as reference for decision makers for corrective measures or further investigation when substantial variation in average doses is observed.

Radioactivity is one of the basic indicators of the environmental state because humankind is continuously exposed to ionising radiations. As Antananarivo is the most populated city of Madagascar, its environmental radioactivity and radiation dose were assessed with the aim of establishing a database for radioactivity levels. Ionising radiations were measured through gamma and X ray global counting. Environmental material radioactivity was characterized by in-situ and laboratory gamma spectrometry. Alpha, gamma and X ray dosimetric measurements were done indoor and outdoor, in daytime and at night. From this work, the environmental gamma and X ray, and radon contribution to natural radiation doses were obtained. We have found that the population of Antananarivo is exposed to an annual average effective dose of 5.3 mSv.y⁻¹, which is two times higher than the world quoted value.

The origin of groundwater salinity in the crystalline basement of southern Madagascar is examined by means of chemical and isotope signatures. These include the isotopes (¹⁸O, ²H, ³H) of water and (⁸⁷Sr/⁸⁶Sr, ¹³C, ¹⁴C) of solutes. Chemical signatures are characterized by trace elements (Br, Sr, F) and the major ion composition. The results suggest two possible mechanisms of mineralization in the Graphite and Androy formations. In the former, palaeomarine intrusion might have contributed to the salinity, whereas water-rock interaction seems to be important in the latter. In both cases, marine aerosols seem to contribute to groundwater salinity. Environmental isotopes have contributed to assessing the origin of the groundwater salinity, although the overall mechanism is not yet clear.

The main objective of this research was to study the size distribution of the toxic elements, undesirables ones and PM10 in the aerosols of Antananarivo urban areas using Total Reflection X-ray Fluorescence. This work was carried out in the framework of a Co-ordinated Research Program organized by the IAEA in 1998. The results of the study show that lead exceeds the recommended value of the WHO (0.5μg.m⁻³) and the PM10 particles exceed also the recommended value (150μg.m⁻³). Therefore, the Antananarivo urban area is classified as saturated zone for both parameters (lead and particulate matter).

The close links between particle physics - the study of the very small - and cosmology - the study of the very large - are reviewed. Many of the most fundamental problems in the macrophysical history of the Universe can only be solved with knowledge of the fundamental laws of microphysics. Conversely, some speculations about particle physics may be testable only in astrophysics. The density budget of the Universe, particle candidates for dark matter and the search for supersymmetry with both astrophysical and accelerator experiments are discussed in more detail.

After a brief introduction about the Dark Matter issue in Astrophysics and Cosmology, different hypotheses for its nature are discussed. The searches for the so-called baryonic type Dark Matter such as MACHOs are presented as well as those from neutrino oscillation experiments which lead to the limits on Ω_ν. The Cold Dark Matter interpretation in the SUSY framework (WIMPs) is introduced and the results from the Direct and Indirect search experiments are discussed and compared. The future potential of both, complementary approaches are also examined.

Standard and non-minimal Higgs searches were performed with data collected by the L3 detector in e⁺e⁻ collisions at 189 – 202 GeV center-of-mass energies. The standard search methodology is described. An example of non-standard search is reviewed as well and results at the above mentionned center-of-mass energies are presented.

The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have collected 2465 pb⁻¹ of e⁺e⁻ collision data at energies between 189 GeV and the highest energy of 209 GeV. Searches for the Standard Model Higgs boson have been performed by each of the LEP collaborations. A lower bound of 114.1 GeV has been obtained at the 95% confidence level for the mass of the Higgs boson. The likelihood analysis shows a preference for a Higgs boson with a mass of 115.6 GeV.

This talk summarizes searches for Higgs bosons beyond the Standard Model prediction at LEP. The analyses are mainly based on the year 2000 data with a total luminosity of 870 pb⁻¹ at center–of–mass energies around 206 GeV. Like in the Standard Model search, no evidence for Higgs bosons has been found. Lower mass limits have been set for various two doublet models, and cross section limits for specific Higgs boson decays have been derived.

This paper reviews the capability of the ATLAS and CMS experiments operating at the Large Hadron Collider to observe the Standard Model Higgs boson and to measure its properties. Their capabilities to discover the SUSY Higgs will also be presented.

During the LEP2 operation, the 4 LEP experiments have collected data at centre–of–mass energies up to 209 GeV. Those data have been analyzed in the search of charginos, neutralinos and sfermions in the framework of the Minimal Supersymmetric Standard Model (MSSM) with R-parity conservation and violation assuming the lightest neutralino to be the Lightest Supersymmetric Particle (SUGRA–models) and in the context of the gauge–mediated supersymmetry breaking theory with R-parity conservation where the LSP is the gravitino (GMSB–model). No evidence for a signal was found in any of the channels. The results of each search were used to derive upper limits on production cross-sections and masses. In addition, for the neutralino LSP with R-parity conservation scenario, the combined result of all searches excludes regions in the parameter space of the constrained MSSM, leading to limits on the mass of the LSP. All limits are given at 95% confidence level, all results are preliminary.

We are presenting results on measurements testing the electroweak theory. The presented data has been taken at the LEP Collider at CERN at center-of-mass energies up to 209 GeV. Updates on the LEP I Z⁰ lineshape and asymmetry measurements will be presented and the current status of the precision W-Boson mass measurement at LEP II will be discussed. The cross section measurement for different standard model processes will be shown. The results will be discussed in the context of standard model fits.

We discuss a number of exact results in N = 1 supersymmetric field theories. We review the results obtained by Seiberg in Super-Yang-Mills (SYM) theories with matter in fundamental representation. We then consider Kutasov-type SYM theories, which also contain matter in the adjoint representation and an appropriate tree–level superpotential. We finally focus on one particular case in the latter theories, a generalization of the theories with equal number of flavors and colors studied by Seiberg, in which non–trivial superconformal theories appear at certain sections of the quantum–modified moduli space. Throughout the paper we stress the role played by duality in the search for exact results.

I summarize our self-contained determinations of the lowest order hadronic contributions ^1,2 to the anomalous magnetic moments a_μτ of the muon and tau leptons, the running QED coupling α(M_Z) and the muonium hyperfine splitting ν. Using an average estimate of the light-by light scattering contribution: a_μ(LL) = 85(18) × 10⁻¹¹, we deduce: , , giving . We also obtain: α⁻¹(M_Z) = 128.926(25) and the Fermi energy splitting: . Lower bounds on some new physics are given, while leads e.g. to m_μ/m_e = 206.768 276(11) in remarkable agreement with the data.

Measurements of the forward-backward asymmetry of the process around the Z⁰ resonance are reviewed. Five reported analyses, using different quark-charge tagging techniques, were performed on the data collected with the DELPHI detector at LEP between 1991 and 1995.

A review of heavy flavour physics results from the LEP experiments is presented. Emphasis is given to the precision test of the Standard Model, to the determination of |V_ub| and |V_cb| and to the study of B meson oscillations, which yield bounds on the unitary triangle.

The parameters x=Δm/Γ and y=ΔΓ/2Γ governing the mixing in the system can be constrained by analyzing hadronic decay modes of the D⁰ meson. The lifetime difference between the D⁰→K⁻ K⁺ and the D⁰→K⁻π⁺ decay modes measures y =−1.0±2.2 (stat)±1.7(syst)% (preliminary) using 12.4 fb⁻¹ of 2001 data. The D⁰ meson can also decay to the wrong sign K⁺π⁻ state either through a doubly Cabibbo suppressed decay or via mixing to the state followed by the Cabibbo favored decay . We give our sensitivity to x and y parameters, from the study of the time dependence of the wrong sign decay rate relative to the Cabibbo favored decay., obtained with 23.2 fb⁻¹ of 1999-2000 data. We give a preliminary measurement of the wrong sign decay rate integrated over time, 0.38 ± 0.04 (stat) ± 0.02 (syst) %.

The D*Dπ and DDρ form factors are evaluated in a full QCD sura rule calculation. We study the double Borel sum rule for the three point function of the meson currents up to order six in the operator product expansion. The form factors are evaluated as a function of the momentum Q² of the D meson and the light meson. These form factors are relevant to evaluate the charmonium absorption cross section by hadrons.

The , , and cross sections as a function of are evaluated in a QCD sum rule calculation. We study the Borel sum rule for the four point function involving pseudoscalar and vector meson currents, up to dimension four in the operator product expansion. We find that our results are smaller than the J/ψ π → charmed mesons cross sections obtained with models based on meson exchange, but are close to those obtained with quark exchange models.

A large signal for CP violation in B-meson decays has been observed by the Belle collaboration. This mixing-induced CP violation is measured by reconstructing one B meson in a CP eigenstate (J/ψK_S, ψ(2S)K_S, χ_c1K_S, η_cK_S, J/ψK_L and J/ψK^*0(K_Sπ⁰)) while tagging the flavor of the partner B meson. From a fit to the time-dependent asymmetry we find sin2φ₁ = 0.99±0.14±0.06, where the first error is statistical and the second systematical.

The BABAR detector, operating at the SLAC PEP-II asymmetric B factory, has collected a sample of 32 million pairs by May 2001, at energies close to the ϒ(4S) resonance. The measurement of sin2β = 0.59 ± 0.14(stat) ± 0.05(syst) , performed with a study of time-dependent CP-violating asymmetries in neutral B decays, establishes CP violation at the 4σ level. In addition, preliminary results on CP-violating asymmetries in the decay channel B⁰ → π⁺π⁻ are presented.

The NA48 experiment at the CERN SPS aims to measure Re(ɛ′/ɛ), the direct CP violation parameter in the K⁰ system, with high accuracy. In 1999 the NA48 collaboration has published its first measurement based on 1997 data. The presented result is based on data collected in 1998 and 1999. The combination with the 1997 result is Re(ɛ′/ɛ) = (15.3 ± 2.6) × 10⁻⁴.

In this talk, I summarize new results ¹ obtained from QCD spectral sum rules (QSSR), on the bag constant parameters entering in the analysis of the mass-differences. Taking the average of the results from the Laplace and moment sum rules, one obtains to order , , in units where f_π = 130.7 MeV. Combined with the experimental data on the mass-differences ΔM_d,s, one obtains the constraint on the CKM weak mixing angle: |V_ts/V_td|² ≥ 20.2(1.3). Alternatively, using the weak mixing angle from the analysis of the unitarity triangle and the data on ΔM_d, one predicts ΔM_s = 18.3(2.1) ps⁻¹ in agreement with the present experimental lower bound and within the reach of Tevatron 2.

Recent QCD results from the four LEP collaborations are presented. In particular, latest measurements of α_s as well as studies of jet rates, particle multiplicities and inclusive distributions using LEP2 data are summarized. Results from analyses of 4-jet observables at LEP1 are given, which include α_s measurements from the 4-jet rate and simultaneous measurements of α_s and the QCD colour factors. Also latest results of the b-quark mass are shown.

Particle correlations are extensively studied to obtain information about the dynamics of hadron production. Prom 1989 to 2000 the four LEP collaborations recorded more than 16 million hadronic Z⁰ decays and several thousand W⁺W⁻ events. In Z⁰ decays, two–particle correlations were analysed in detail to study Bose-Einstein and Fermi–Dirac correlations for various particle species. In fully–hadronic W⁺W⁻ decays, particle correlations were used to study whether the two W bosons decay independently. A review of selected results is presented.

Recent results from the HERA ep collider are discussed with emphasis on the transition from short to long distance phenomena in QCD. The results cover inclusive ep scattering, inclusive diffractive scattering, vector meson production, and deeply virtual Compton scattering (DVCS).

A review is presented of the different theoretical models proposed to approach consistently the interplay between soft and hard physics, that can now be studied experimentally at HERA for the first time.

Cross section measurements made with the H1 detector at HERA are reported for the reactions γp → ωp and γp → (ωπ⁰)X, and on searches for the reactions γp → π⁰N*, γp → f₂(1270)X, and , where N* denotes an excited nucleon state. The average photon - proton centre-of-mass energies at HERA were 〈W〉 = 200 GeV and 215 GeV. Cross sections for the Pomeron -mediated reactions were determined in agreement with previous measurements and theoretical expectations. Processes mediated by Odderon - photon fusion could not be observed; upper limits on cross sections are below predictions from a non-perturbative QCD model.

We discuss the motivation for introducing a trajectory which is odd under C-parity in diffractive processes. We present some reactions where such a trajectory can be important and stress the relevance of photoproduction experiments at HERA. We present the results of a model calculation and discuss some recent results of H1.

We decompose U(1) gauge fields into a monopole and photon part across the phase transition from the confinement to the Coulomb phase. We analyze the leading Lyapunov exponents of such gauge field configurations on the lattice which are initialized by quantum Monte Carlo simulations. It turns out that there is a strong relation between the sizes of the monopole density and the Lyapunov exponent.

A few aspects of the mechanism of confinement of color by monopole condensation are reviewed.

The following section are included:

• Traditional acknowledgements

• English speech

The following sections are included:

• LIST OF PARTICIPANTS

• Conference Photos