Abstract the 14th Rencontres de Blois

Abstract for the Keynote Address for the 14th Rencontres de Blois on
"Matter-Antimatter Asymmetry":

COSMIC ANTIMATTER?

F.W. Stecker
Lab. for High Energy Astrophysics
NASA Goddard Space Flight Center

The question of the presence or absence of cosmologically significant amounts of antimatter in the universe is one of fundamental significance. Its answer gives important clues for our understanding of both particle physics and cosmology. To date, we have not found any convincing evidence for the existence of antimatter on a cosmological scale. Is the absence of evidence for antimatter to be taken as evidence of absence? What observational tests are there for cosmologically distant antimatter, considering that an antimatter galaxy would look identical to a matter galaxy when viewed by the Hubble or any other telescope? If there is indeed no antimatter in the observable universe, is its absence the result of broken symmetries, inflation, or both?

CP Violation:An Historical Review

Lincoln Wolfenstein Carnegie Mellon University

For 35 years after the discovery of CP violation in 1964 the only manifestation was a small effect in the K0 system. It remained an open question whether CP violation was explained by a phase in the standard model Hamiltonian that changed flavor by one unitor was due to some new superweak interaction. The standard model predicted large CP-violating effects in the B system, one of which has now been observed. A number of fundamental questions remain to be answered.

Current projects on CP Violation in kaons

Juliet Lee-Franzini
Frascati

Three European experiments are engaged at present in the study of CP violation in the kaon system. In particular, NA48/1 and KLOE are concerned with the K-short decaying into three pions, while NA48/2 and KLOE study the charged kaon decaying into three pions^“ Dalitz plot asymmetries. I will discuss the experimental set ups as well as the anticipated sensitivities.

Antimatter Measurements with the HEAT Balloon Experiment

Stephane Coutu
coutu@phys.psu.edu
The Pennsylvania State University

The High Energy Antimatter Telescope is a magnet spectrometer complemented by an array of particle detectors. It was flown on high altitude balloons in 1994, 1995, 2000 and 2002 from locations in New Mexico, USA and Manitoba, Canada. With it, we have measured the positron content of the cosmic-ray flux at energies between 1 and 50 GeV, and the antiproton content from 4 to 50 GeV. We have found both antiparticle species to be substantially in agreement with models of secondary antimatter production in interstellar collisions of hadronic cosmic rays. The HEAT measurements will be described and compared with others and with model predictions. The possibility of primary antimatter from sources such as annihilating dark matter particles will be explored.

Title: Electroweak baryon number violation

Speaker: Frans R. Klinkhamer

Abstract:

Electroweak baryon number violation is believed to play a crucial role for the creation of the matter-antimatter asymmetry in the early universe.

In this talk, we review the basic mechanism, that is, discuss the behavior (spectral flow) of chiral fermions in nontrivial Yang-Mills gauge field backgrounds.

For dissipative Yang-Mills gauge fields, the spectral flow is well-known and we recall the main result. For nondissipative gauge fields, which are the ones relevant for the early universe, there appears to be a new contribution to the spectral flow. Clearly, this issue needs to be investigated further.

The AMS Experiment:
Particle Physics and Particle Astrophysics in Space

Martin Pohl

Email Martin.Pohl@cern.ch

I give a short introduction on the observational methods in the search for cosmic antimatter and the role of AMS in this context. The AMS pilot experiment AMS-01, flown on board of the Space Shuttle in 1998, is then shortly described and selected physics results from this flight are presented. I then give a status report on the construction of the AMS-02 detector, to be installed on the International Space Station in 2004 for three years of data taking. The physics prospects for this ambitious detector are presented for what concerns the search for antimatter, but also the search for dark matter, origin and transport of cosmic rays and astrophysics with high energy photons.

Guido Martinelli

Universite de Roma

Theoretical interpretation of e'/e
The theoretical framework for the calculation of e'/e is discussed and present predictions compared to the experimental measurements. Possible contributions from physics beyond the Standard Model will also be considered.

C,P,T are broken. Why not CPT?

L.B.Okun
ITEP, Moscow, Russia

Abstract

Two pillars of an effect of discrete asymmetry are discussed: 1.the breaking the corresponding symmetry at the basic level ( that of Lagrangian(?));2.the manifestation of asymmetry at the level of the square of modulus of the amplitude.The classification of possible types of symmetry breaking leads us to the Procrustean "CPT cube".
The subtleties of asymmetry manifestations are illustrated by simple
examples.

"High precision laser spectroscopy of antiprotonic helium atoms"

Eberhard Widmann, Tokyo UNIVERSITY

Antiprotonic helium is a metastable (lifetime > 3 microseconds)
3-body system consisting of an antiproton, an electron and an
alpha particle, which was serendipitously discovered by Tokyo
group about 10 years ago.

High-precision laser spectroscopy of antiprotonic helium-4 (as
well as helium-3) is being done at CERN's new low-energy
antiproton source, AD. The results are compared with the
state-of-the-art 3-body QED calculations, from which we have
deduced that the antiproton and proton charges and masses
agree to within 60 ppb. Furthermore, we have recently succeeded
to resolve the hyperfine structure of antiprotonic helium by means
of a laser-microwave triple resonance method, which will
enable us to deduce antiprotonic magnetic moment.

Title:"Cosmological parameters: status and prospects"

Alessandro Melchiorri
Oxford

Abstract:"A survey is made of the present observational status on
cosmological parameters covering both microwave background anisotropies
and large scale structure observations such as galaxy clustering and
object abundances. I then move to some non-standard aspect of parameter
extraction like quintessence, extra-background of relativistic
particles and variations in fundamental constants.
Finally, I will discuss a few mechanisms of secondary anisotropies
and new experimental constraints."

M.Nozaki
Kobe University

The BESS results and prospects

Abstract

The primary purpose of the BESS experiment is to measure the energy spectrum
of cosmic-ray antiprotons and to explore the existence of possible
antiprotons sources originated from the early Universe. A magnet
spectrometer equipped with a superconducting solenoid, tracking devices and
other detectors for particle identification has been launched to the top of
the atmosphere. Since 1993, a total of 1800 antiprotons have been collected
by seven balloon flights performed in northern Canada. Although we have
observed an energy spectrum characteristic of secondary antiprotons, the
result is not conclusive in the energy region below 1 GeV because of
insufficient statistics. A much longer observation with a more transparent
apparatus is needed to improve the statistics and to extend the measurement
to lower energies. We plan to fly a new BESS-Polar spectrometer in
Antarctica.

Y.Teramoto
Osaka University

The Belle experiment

abstract:

Current status of the CP violation measurements by the
Belle detector will be presented mainly on sin(2phi1)
and sin(2phi2). The descriptions include the principle
of measuements, event selections, reconstructions,
B and B-bar tagging. In addition, brief descriptions
of other possible channels: phi3 by B->D(CP)K and
2phi1+phi3 by B->D*pi will be mentioned.

"CP Violation in K and B Meson Decays, Introduction"
K. R. Schubert, TU Dresden

Abstract:

Particle Physics Experiments have established five CP-violating
observables: Re(epsilon_K), Im(epsilon_K), Re(epsilon_K^prime),
Im(epsilon_K^prime), and A(B0,B0bar -> J/psi K). The five results
are very shortly reviewed. They are then discussed with respect
to their classification into four types of CP violation:
(1) CPV in meson-antimeson oscillations,
(2) CPV in decays with contribution of strong phases,
(3) CPV in decays without contribution of strong phases,
(4) CPV in the interference between oscillation and decay.
In the neutral K-meson system, type (1) and type (4) are strongly
related because of unitarity.

Neutron -> Antineutron Oscillations

Yuri Kamyshkov (University of Tennessee)

Abstract

Experimental observation of nucleon instability is one of the missing
components required for the explanation of baryon asymmetry of the universe.
Proton decay with the modes and rates predicted by the original
(B-L)-conserving SU(5) GUT scheme is not observed experimentally. There are
reasons to believe that (B-L) might not be conserved in nature, thus leading
to the nucleon decay into lepton+(X), neutrinoless double-beta decays, and
most spectacularly to the transitions of neutrons to antineutrons. A
motivation and a new experimental approach to search for transition of
neutron
to antineutron will be discussed. A new search of n-nbar can be performed in
a
reactor-based experiment at HFIR/ORNL with a sensitivity ~1000 times higher
than in the previous experiments.

D.Bryman
University of British Columbia, Vancouver.

Title: Measurements of K -> pi nu nubar decays: results and prospects.

Subject:

Recent results from the BNL E787 measurement of K+ -> pi+ nu nubar and
progress made by its successor, E949, which has just begun to take data,
will be discussed. In addition, the plans for future projects including
the KOPIO experiment designed to measure the CP-violating decay
K_L -> pi0 nu nubar will be presented.

R.Tschirhart
Fermilab

"CP Violation in high intensity kaon beam experiments."

The prospects and techniques of future ultra-rare kaon decay
experiments will be reviewed. These experiments are enabled
by the very high intensity hadron beam facilities at Brookhaven
National Lab, Fermilab, and KEK/JHF. Particular attention will be
paid to precision measurement of the K ->pi,nu,nubar process at
these facilities.

M.Doser
CERN

"The ATHENA experiment"

Abstract: The goal of the ATHENA experiment is the production and study
of Antihydrogen.
All components of the experiment are now installed and functional, and
first data have been
taken. The characteristics of the experiment, as well as first results,
will be presented.

A.Dolgov
Ferrara and ITEP

Cosmological matter-antimatter asymmetry.

Abstract.

Models of baryogenesis leading to astronomically significant amount of
antimatter in the universe are reviewed. Observational features are
analyzed.

Investigating Lorentz and CPT symmetry with antihydrogen

Neil Russell
Northern Michigan University

Interesting tests of CPT and Lorentz symmetry will be possible with
the availability of trapped antihydrogen. A discussion is given in the
context of a standard-model extension with minuscule CPT- and
Lorentz-violating terms. The extension could arise from an underlying
Planck-scale theory, such as string theory. Transitions in hydrogen and
antihydrogen that exhibit leading-order effects are identified in the
standard-model extension. Comparisons of these transitions in antimatter
atoms with the corresponding transitions in regular atoms will allow for
bounds on parameter combinations that cannot be accessed with regular
atoms alone.
This talk will give some background on the standard-model extension,
discuss the applications to antihydrogen, and consider applications to
several other systems of interest.

Z. Berezhiani (L'Aquila and Gran Sasso)
"Leptogenesis Mechanisms"

abstract:
We review different scenarios of generation of the
matter - antimatter asymmetry in the early universe
through the leptogenesis mechanism, and their relations
to the neutrino mass and mixing schemes

ANDRZEJ J. BURAS, | phone: +49/89/289 12371
Technical University Munich, | fax: +49/89/289 14655
Physics Dept.-Theo. Physics T31,| Internet email:
D-85748 Garching, Germany | Andrzej.Buras@ph.tum.de

Unitarity Triangle: 2002

We review the present status of the Unitarity Triangle determined
from V_us, V_ub, V_cb, Delta M_d, Delta M_s, epsilon_K and the
most recent results on sin 2beta from the CP-asymmetry a_(psi K_S).
We pay particular attention to theoretical uncertainties and to
the error analysis.

Jean Orloff
Clermont-Ferrand

The production of antimatter in our galactic backyard

We estimate the production of anti-nuclei by collisions of cosmic rays on the
interstellar gas. A simple coalescence model is fitted on existing p-p
collider data and used to source the anti-deuterium and anti-helium fluxes,
which are then propagated through the galactic magnetic fields before
reaching us. We compare the resulting fluxes with current and future
experimental limits, as well as possible exotic signals like anti-stars or
dark matter annihilation in the halo.

Experimental results od T and CPT Symmetries

E.Aslanides (CPPM)

The experimental tests of T and CPT symmetries will be presented
with emphasis on the neutral kaon system. The scale of mass difference
between the weak interaction eigenstates of this system coupled to the
strangeness tagging capability lead to unprecedented variety and
precision in the study of discrete symmetries.

Title "Antimatter production near a Black Hole Horizon:
Necessary conditions for black hole appearances"

Lev Titarchuk , NASA Goddard

Abstract
"I present the main spectral and timing features of X-ray radiation which
have to be seen in black hole systems only. I demonstrate that
photon-electron interaction along with the general relativistic effects
lead to t he formation a specific spectrum. The photon bending near a Black
hole Horizon of the effectively upscattered photons results in the powerful
pair outflow which can be responsible for the jet formation in black holes."

"Antimatter in Cosmic rays: the Dark matter - cosmic ray connection"
Fiorenza Donato

We provide the results on the flux of secondary antiprotons in cosmic rays
as obtained in a two--zone diffusion model. This flux is fully consistent
with results on stable nuclei.
The theoretical flux is compared with measurements of antiprotons near
Earth.
All the uncertainties in the calculation are identified and quantified.

We also present the results of the calculation of antideuterons coming
from neutralino dark matter annihilation in the halo of our Galaxy.
We discuss the power of both antiproton and antideuteron maesurements on
the search for cold (supersymmetric) dark matter in the Milky Way.

B.Peyaud

Direct CP Violation

ABSTRACT:
The measurement of direct CP violation in the neutral system has been
vigorously carried out by experiments at CERN and Fermilab since 1981.
We review some important results obtained by these experiments among
which the clear evidence of direct CP violation and of T violation.

PS1 and PS2
S. T'Jampens
LLR Ecole Polytechnique

Title
"Measurement of $\cos 2\beta$ with $B^0 \to J/\psi K^{*0}$, s-quark helicity conservation and CKM matrix"

Abstract

The decay $B^0 \to J/\psi K^{*0}$, with $K^{*0} \to K^0_s \pi^0$ is sensitive to both $\sin 2\beta$ and $\cos 2\beta$. However the sign determination of $\cos 2
\beta$ itself suffers from a two-fold ambiguity in
the determination of the strong phases entering the description of the decay. In principle, this prevents the sign of $\cos 2\beta$ to be determined with this decay alone.
However, theoretical assumptions can be
made to define a set of "preferred" strong phases, leading to a preferred sign of $\cos 2 \beta$.
We first introduce the observables in the $B^0 \to J/\psi K^{*0}$ decay, to exhibit the source of the ambiguity. We then summarize the arguments leading to the
preferred choice of strong phases. This allows to
consider a preferred sign of cos2beta, for which we the examine the consequences on the CKM matrix.

"Antimatter in Cosmic rays: the Dark matter - cosmic ray connection"
by Fiorenza Donato (LAPTH, Annecy)

Abstract:
We provide the results on the flux of secondary antiprotons in
cosmic rays as obtained in a two--zone diffusion model. This flux is
fully consistent with results on stable nuclei. The theoretical flux is
compared with measurements of antiprotons near Earth. All the
uncertainties in the calculation are identified and quantified.
We also present the results of the calculation of antideuterons coming
from neutralino dark matter annihilation in the halo of our Galaxy. We
discuss the power of both antiproton and antideuteron maesurements on
the search for cold (supersymmetric) dark matter in the Milky Way.

" Antimatter from primordial black holes "
A. Barrau (ISN Grenoble)

Abstract:
Primordial black holes (PBHs) are among the most exciting
enigma of modern physics. Recent experimental measurements of cosmic
rays with better accuracy, theoretical investigations on the possible
formation mechanisms and detailed evaporation processes have revived the
interest in such astrophysical objects. This talk aims to use the latest
developments in antiproton propagation models (Maurin et al. and Donato
et al.) together with new data from AMS, BESS and CAPRICE experiments to
constrain the local amount of PBH dark matter. Depending on the
diffusion halo parameters, we derive an average upper limit of the order
of 1.7E-33 g/cm3. The anti-deuteron emission is also studied in a
coalescence scheme and is proven to be an interesting probe for PBH dark
matter.

"Antimatter search with L3 using the obscuration of the protons by the moon (L3-Cosmics)"
J-F. Parriaud

Abstract:
Present measurements on the antiproton flux in cosmic rays are
limited to momenta below 50 GeV/c. Measurements to set upper limits to
the antiproton flux at higher energies, where antiprotons from secondary
origin no longer contribute, are of current interest. To set such a
limit, the deficit of muons originating from the Moon's direction is
measured as a function of the muon momentum threshold with the L3+C
detector at LEP, CERN. The observation of the position and shape of such
a shadowing effect allows a determination of the electric charge of TeV
cosmic rays through the bending of the particles by the Earth's magnetic
field. After a description of the experiment, a preliminary result will
be reported.

"A Seesaw-invariant Texture of Lepton Mass Matrices for Leptogenesis and Neutrino Oscillations"
Zhi-zhong XING

Abstract:
We propose a simple SO(10)-inspired model for Dirac and heavy
Majorana neutrino mass matrices of four texture zeros, from which the
observed baryon asymmetry can be interpreted via the leptogenesis
scenario. We show that the light Majorana neutrino mass matrix keeps the
same texture after the seesaw mechanism is applied, and it may lead to
nearly bi-maximal lepton mixing with large CP violation.

" Cosmology, baryogenesis and search for extraterrestrial antimatter"
Maxim Khlopov

Abstract:
It is recently shown that the possibility of small amount of
sufficiently large to survive regions of antimatter in baryon
asymmetrical Universe can be the natural consequence of inflational
models with nonhomogeneous baryosynthesis and that this possibility
escapes the contradictions with severe constraints on antimatter
annihilation. The links between the parameters of such models with the
possible forms of antimatter in the modern Universe are specified. The
gamma ray, cosmic ray effects of antimatter globular cluster in our
Galaxy are discussed together with the possibility of antimeteorite
effects in the Solar system

" Baryon-dominated universe with macroscopically large antimatter
regions"
Alexander Sakharov:

Abstract:
The whole set of astrophysical data indicates that our
Universe is globally baryon asymmetrical. Nevertheless a possibility of
existence of relatively small amount of sufficiently large antimatter
regions is not excluded. Such regions can survive the annihilation with
surrounding matter only in the case if their sizes exceeds the certain
scale. It is shown that the quantum fluctuations of a complex scalar
field caused by inflation can lead to the origin of large antimatter
domains progenitors, which contribute very insignificantly to the total
volume of the Universe. The resulting distribution and evolution of
outcoming antimatter regions could cause every galaxy to be a harbor of
an anti-star globular cluster. The existence of one of such anti-star
globular cluster in our Galaxy, would not disturb the observable
$\gamma$-ray background, but the expected fluxes of $\overline{^4He}$
and $\overline{^3He}$ nuclei would be definitely accessible for the
sensitivity of coming AMS02 experiment.

Leptogenesis and neutrino masses at the TeV scale".
Thomas Hambye

Abstract:

In this short talk is investigated the possibility to generate
the neutrino masses and the matter-antimatter asymmetry of the universe
from a same source of lepton number violation and at a directly testable
scale (of order 1 TeV).
After reviewing the various problems which explain why the usual
leptogenesis models cannot be efficient at a scale as low as one TeV, we
present a general mechanism which, based on a out of equilibrium three
body decay scenario, naturally avoids these problems. A model based on
this mechanism is presented.

Session: poster

Kirilova

Abstract:

The possibility of natural and abundant creation of antimatter
in the Universe in a non-GUT baryogenesis model with a scalar field
condensate is described. In this scenario the vast quantities of
antimatter, corresponding to galaxy cluster and supercluster scales
today, can be naturally separated. Theoretical and observational
constraints on such antimatter regions are discussed.

PS2
Jerôme Charles(Centre de Physique Theorique, Universite de Marseille)
"Extracting alpha from charmless B decays: status and perspectives"

Abstract.- In view of the recent BaBar and Belle preliminary data on the
time-dependent CP-asymmetry in B_d->pi+pi-, I will briefly review and
comment the different methods that could help extracting the CKM angle
alpha.

PS2
Nikolai Uraltsev
Universita di Milano Bicocca

"Extracting $V_{cb}$ and $V_{ub}$ -- The Challenge for Heavy Quark Theory"

Abstract.- I would like to give a brief dive into the heavy quark
expansion using extraction of V_cb and V_ub as a practical application,
putting emphasis on sum rules and how they allow to decrease
uncertainties in both V_cb and V_ub by imposing essential constraints.

PS2
Zhi-zhong Xing

Theory Division, IHEP, Chinese Academy of Sciences, Beijing

"Determination of strong and weak phases in B_d -> D^*+-D^*-+ and B_s -> D^*+-_sD^*-+_s decays"

Abstract.- We study the possibilities to extract strong and
weak phases from the decays modes B_d -> D^*+D^-
and D^+D^*- as well as B_s -> D^*+_sD^-_s and
D^+_sD^*-_s in a model-independent way. As for the
decay modes B_d -> D^*+D^*- and B_s -> D^*+_sD^*-_s,
we show that it is possible to determine the weak
CP-violating phase \beta without doing the angular
analysis. Decays of this type may provide a window
to test naive factorization hypothesis in B transitions
to two heavy charmed mesons. Finally we give a brief
analysis of possible final-state rescattering effects in
B -> D^(*)\bar{D}^(*) modes.

PS2
Emi Kou

University of Durham

"Direct CP asymmetry in exclusive charmless B decays and the pQCD
approach"

Abstract.- The B factory experiments (Belle and Babar) announced their values for
the direct CP asymmetry in B to pi^+ pi^- process. The direct CP
asymmetry will be measured in various modes, like B to K_s phi and
B to K_s eta', in the near future. Thus, it is very interesting to
discuss what can be extracted from those measurements now. I would like to
discuss on this matter based on the so-called pQCD approach which
has been developed to analyze exclusive charmless B decays. Talk will
include a short review of the pQCD approach and its results for pi pi,
K pi, K phi and K eta(') processes.

PS4 ("Theory developments") :

Franco Buccella (Universita di Napoli)

"Exclusive non-leptonic decays of D particles."

Abstract.- Final state interaction in resonant and exotic channels
as well as the annihilation diagrams are necessary tools to obtain
a satisfactory description of PP and PV final states.Preliminary
results will be presented of the attempts to extend the description
to VV final states. The improved agreement of the updated data with
the Cabibbo forbidden final states for PP and PV strongly encourages
the continuation of the study.

PS2
Songhoon Yang (CALTECH)

TITLE: Constraints on New Physics from $B\rightarrow l^+l^-$ Search

ABSTRACT:
New limits on $B\rightarrow l^+l^-$ search are used to constrain the new physics.
For the case of leptoquark models and SUSY without R-parity,
this will represent a substantial extension of explored parameter space.

PS1
Matthias Buechler (R)

TITLE: Dispersive treatment of K to pi pi

ABSTRACT:
We propose a new method to obtain the $K \to \pi \pi$ amplitude from $K
\to \pi$ which allows one to fully account for the effects of final
state interactions. The method is based on a set of dispersion relations
for the $K \to \pi \pi$ amplitude in which the weak Hamiltonian carries
momentum.

PS1
Santiago Peris (R)

TITLE: Penguins at large Nc and CP violation

ABSTRACT:
I will explain the present use of the large-Nc expansion of QCD for
computing penguin matrix elements

PS1
Joachim Prades (R)

TITLE: Matching the EW penguins Q7 and Q8

ABSTRACT:
Exact analytical expressions for DeltaS=1 coupling IMG_E in terms of
observable spectral functions are given. This coupling determines the
size of DeltaI=3/2 constributions to e'/e. We show analytically how the
scheme dependence and scale dependence vanish to all orders in 1/N_C
and NLO in alpha_S explicitely for both Q_7 and Q_8. Numerical results
are derived for bothe Q_7 and Q_8 from the tau data and known results
on the scalar spectral functions. In particular we study the effect of
all higher dimensionnal operators.

PS1
Cristina Lazzeroni (R)

TITLE: NA48 Measuremnt of Re(e'/e) Cristina Lazzeroni (R)

ABSTRACT:
The NA48 experiment at the Cern SPS has measured the parameter Re(e'/e)
to be greater than zero by more than five standard deviations. This
firmly establishes the existence of direct CP violation in the neutral
kaon system.

PS1
Richard Batley (R)

TITLE:
Kaon Rare Decay Results from NA48

ABSTRACT:
Recent results on rare K_L and K_S decays relevant to CP violation
obtained by the NA48 experiment at the CERN SPS will be presented. The
prospects from future running with a high intensity K_S beam will also
be summarised.

PS1
Mike Arenton (R)

TITLE: Results on Rare KL Decays from KTeV

ABSTRACT:
Recent results on rare $K_L$ decays from KTeV are presented,
including data from both the 1997 and 1999 runs. Searches for lepton
number violating decays will be shown. Studies of $K_L \rightarrow
\mu^+\mu^-e^+e^-$ and $K_L \rightarrow \pi^+\pi^- e^+e^-$ with the
full data sample will be presented. Form factors in the decay $K_L
\rightarrow e^+e^-\gamma$ will be discussed.

PS1
Tim Holmstrom (R)

TITLE: A Search for CP Violation in Hyperon Decays by the HyperCP Experiment at Fermilab

ABSTRACT:
The HyperCP collaboration is performing a precision search for CP
violation in hyperon decays; these decays are sensitive to sources of
CP violation that {\em e.g.}\ neutral-kaon decays are not. The measured
CP observable is proportional to the difference between the product of
the $\Xi^-$ and $\Lambda$ decay $\alpha$ parameters and that of the
CP-conjugate decays. About 2.5 billion fully-reconstructed $\Xi^-
\rightarrow \Lambda\pi^- \rightarrow p\pi^-\pi^-$ and
$\overline{\Xi}$$^+ \rightarrow \overline{\Lambda}\pi^+ \rightarrow
\overline{p}\pi^+\pi^+$ decays were taken in two fixed-target runs at
Fermilab, allowing a statistical sensitivity of about
$2{\times}10^{-4}$ in the CP asymmetry. Preliminary results from a
fraction of the data will be presented.

PS1
Gianmaria Collazuol (R)

TITLE: A Precision measurement of charged kaon decay parameters

ABSTRACT:
A new physics program, proposed by the NA48 collaboration for the year
2003, has been approved at CERN for an high statistics study of
charged kaon decays. An upgraded NA48 setup with a transition
radiation detector and a novel design for simultaneous $K^+/K^-$ beams
allow to measure the direct CP violation in charged kaon decays into
three pions with an accuracy of $\sim 2 \dot 10^{-4}$. In addition new
experimental investigations on chiral symmetry will be performed with
more than $10^{6}$ $K_{e4}$ decays and other rare decays.

PS2
Petersen

TITLE: Measuring the Weak Phase gamma in Color Allowed B+- --> D0 K+- pi0 Decays

ABSTRACT
We present a method to measure the weak phase gamma in the
threebody decay of charged B mesons to the final states
D0 K+- pi0. These decays are mediated by interfering amplitudes which
are color allowed and hence relatively large. As a result, large CP
violation effects that could be observed with high statistical
significance are possible. In addition, the threebody decay helps
resolve discrete ambiguities that are usually present in measurements
of the weak phase. The experimental implications of conducting these
measurements with threebody decays are discussed, and the sensitivity
of the method is evaluated using a simulation.

Poster
Daniel Goldin, Cibran Santamarina Rios

TITLE: DIRAC PS-212. An experiment to measure pionium lifetime.

ABSTRACT
The pionium is the atom formed by a positively charged pion (pi+) and
its corresponding antiparticle (pi-). The strong interaction of this
matter-antimatter bound system is explained by the chirally symmetric
lagrangian of the Chiral Perturbation Theory (ChPt).
DIRAC experiment is measuring the pionium lifetime with a double *arm*
spectrometer located at the CERN PS ring. We aim to reach 10%
accuracy in the experimental result analyzing the low relative
momentum spectrum of pi+ pi- pairs.

PS4
N. Cosme (UniversitÈ libre de Bruxelles)

TITLE: CP violation from dimensional reduction : a simple example

ABSTRACT:
CP is an essential symmetry and the caracteristic symmetry of
gauge interactions. In a theory truly unified around a gauge component,
the origin of the observed small CP breaking thus raises a fundamental
question.
Whe show in a simplistic model of compactification of 4+1 to 3+1
dimensions how
such CP violation takes place in a gauge context through the Hosotani
mechanism;
we then outline how this mechanism can be extended to more realistic
cases