1,288 research outputs found
The Heavy-Ion Physics Programme with the ATLAS Detector
The CERN LHC will collide lead ions at TeV per nucleon pair and will provide crucial information about the formation of a quark--gluon plasma at the highest temperatures and densities ever created in the laboratory. We report on an updated evaluation of the ATLAS potential to study heavy--ion physics. The ATLAS detector will perform especially well for high phenomena even in the presence of the high--multiplicity soft background expected from lead-lead collisions, and most of the detector subsystems retain their nearly full capability. ATLAS will study a full range of observables which characterize the hot and dense medium formed in heavy--ion collisions. In addition to global measurements such as particle multiplicities and collective flow, heavy--quarkonia suppression, jet quenching and the modification of jets passing in the dense medium will be accessible. ATLAS will also study forward physics and ultraperipheral collisions using Zero Degree Calorimeters
Heavy Quarkonia Perspectives with Heavy-Ions in ATLAS
ATLAS will study a full range of observables and phenomena which characterize the hot dense medium formed in heavy-ion collisions, and in particular heavy quarkonia suppression which provides a handle on deconfinement mechanisms. As each quark-antiquark bound state is predicted to dissociate at a different temperature, the systematic measurement of the suppression of these resonances should provide some sort of thermometer of the early stage of the system evolution. We report on an evaluation of the ATLAS potential to measure resonances of the Upsilon and J/psi families created in Pb+Pb collisions
Quarkonia Physics in Heavy-Ion collisions with the ATLAS Detector
Updated evaluation of the ATLAS capabilities to study heavy quarkonia physics in Pb+Pb collisions
Measuring the quark condensate from the decays tau -> 3 pi + nu(tau)
The possibility of detecting the S-wave of the decays tau -> 3 pi + nu(tau)
in the threshold region is explored, with emphasis on the sensitivity to the
size of the quark antiquark condensate .Comment: contribution to QCD99, 4 pages, Latex, using espcrc2.sty (included),
2 PS figur
Three channel model of meson-meson scattering and scalar meson spectroscopy
New solutions on the scalar -- isoscalar phase shifts are analysed
together with previous results using a separable potential model of
three coupled channels (, and an effective
system). Model parameters are fitted to two sets of solutions obtained in a
recent analysis of the CERN-Cracow-Munich measurements of the reaction on a polarized target. A relatively
narrow (90 -- 180 MeV) scalar resonance is found, in contrast
to a much broader ( MeV) state emerging from the analysis
of previous unpolarized target data.Comment: 10 Latex pages + 6 postscript figure
Heavy Ion Physics at the LHC with the ATLAS Detector
The ATLAS detector at CERN will provide a high-resolution
longitudinally-segmented calorimeter and precision tracking for the upcoming
study of heavy ion collisions at the LHC (sqrt(s_NN)=5520 GeV). The calorimeter
covers |eta|<5 with both electromagnetic and hadronic sections, while the inner
detector spectrometer covers |eta|<2.5. ATLAS will study a full range of
observables necessary to characterize the hot and dense matter formed at the
LHC. Global measurements (particle multiplicities, collective flow) will
provide access into its thermodynamic and hydrodynamic properties. Measuring
complete jets out to 100's of GeV will allow detailed studies of energy loss
and its effect on jets. Quarkonia will provide a handle on deconfinement
mechanisms. ATLAS will also study the structure of the nucleon and nucleus
using forward physics probes and ultraperipheral collisions, both enabled by
segmented Zero Degree Calorimeters.Comment: 9 pages, 8 figures, submitted to the Proceedings of Quark Matter
2006, Shanghai, China, November 14-20, 200
Chiral Lagrangians
An overview of the field of Chiral Lagrangians is given. This includes Chiral
Perturbation Theory and resummations to extend it to higher energies,
applications to the muon anomalous magnetic moment,
and others.Comment: Invited talk at the XX International Symposium on Lepton and Photon
Interactions at High Energies 23rd-28th July 2001, Rome Italy, 15 pages, uses
ws-p10x7.cls Changes: 2 references added, numbers in g-2 hadronic changed
slightl
On CP-Odd Effects in K_L \to 2\pi and K^{\pm} \to \pi^{\pm} \pi^{\pm} \pi^{\mp} Decays Generated by Direct CP Violation
The amplitudes of the K^{\pm} \to 3\pi and K \to 2\pi decays are expressed in
terms of different combinations of one and the same set of CP-conserving and
CP-odd parameters. Extracting the magnitudes of these parameters from the data
on K \to 2\pi decays, we estimate an expected CP-odd difference between the
values of the slope parameters g^+ and g^- of the energy distributions of "odd"
pions in K^+ \to \pi^+\pi^+\pi^- and K^- \to \pi^-\pi^-\pi^+ decays.Comment: 12 pages, no figure
Pion Interactions in Chiral Field Theories
We study in various chiral models the pion charge radius, form
factor ratio, amplitude, charge pion
polarizabilities, amplitude at low
energies and the s-wave I = 0 scattering length. We find that a
quark-level linear sigma-model approach (also being consistent with tree-level
vector meson dominance) is quite compatible with all of the above data.Comment: 12 pages, 9 eps figure
T-odd correlations in charged Kl4 decays
We analyse the sensitivity to physics beyond the SM of T-odd correlations in
decays, which do not involve the lepton polarization. We show that
a combined analysis of and decays can lead to new
constraints about CP violation in charged-current interactions,
complementary to those obtained from the transverse muon polarization in
and of comparable accuracy.Comment: 6 pages (LaTeX
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