801 research outputs found
Physical Information in the Thermal Continuum Dilepton Spectra
We consider the intermediate mass continuum of dileptons (between and
) in ultrarelativistic heavy--ion collisions. The thermal signal
depends essentially on thermodynamic state parameters of the hottest parton
stage as convoluted with an involved detector
acceptance function. A refined analysis of the transverse pair momentum
spectrum at fixed dilepton transverse mass can reveal the maximum temperature
of parton matter.Comment: 3 LaTeX pages including eps figures, contribution to the Erice School
on Nuclear Physics 1998 (to be published in "Progress in Particle and Nuclear
Physics"
QCD sum rules for D mesons in dense and hot nuclear matter
Open charm mesons (pseudo-scalar and scalar as well as axial-vector and
vector) propagating or resting in nuclear matter display an enhanced
sensitivity to the chiral condensate. This offers new prospects to seek for
signals of chiral restoration, in particular in p-A and p-bar-A reactions as
envisaged in first-round experiments by the CBM and PANDA collaborations at
FAIR. Weinberg type sum rules for charming chiral partners are presented, and
the distinct in-medium modifications of open-charm mesons are discussed. We
also address the gluon condensates near Tc and their impact on QCD sum rules.Comment: 6 pages, 7 figures, conference proceeding
Relativistic Expansion of Electron-Positron-Photon Plasma Droplets and Photon Emission
The expansion dynamics of hot electron-positron-photon plasma droplets is
dealt with within relativistic hydrodynamics. Such droplets, envisaged to be
created in future experiments by irradiating thin foils with
counter-propagating ultra-intense laser beams, are sources of flashes of gamma
radiation. Warm electron-positron plasma droplets may be identified and
characterized by a broadened 511 keV line
Is there a unique thermal source of dileptons in Pb(158 AGeV) + Au, Pb reactions?
An analysis of the dilepton measurements in the reactions Pb(158 AGeV)
+ Au, Pb points to a unique thermal source contributing to the invariant mass
and transverse momentum spectra. Effects of the flow pattern are discussed.Comment: 7 LaTeX pages including eps figure
Production of \phi Mesons in Near-Threshold \pi N and N N Reactions
We analyze the production of mesons in and NN reactions in the
near-threshold region, using throughout the conventional ``non-strange''
dynamics based on such processes which are allowed by the non-ideal
mixing. We show that the occurrence of the direct
interaction may show up in different unpolarized and polarization observables
in reactions. We find a strong non-trivial difference between
observables in the reactions and caused by the
different role of the spin singlet and triplet states in the entrance channel.
A series of predictions for the experimental study of this effect is presented.Comment: 35 pages including 18 figure
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