3,725 research outputs found
Strange Particle Production Mechanisms in Proton-Proton Collisions at RHIC
We present data on strange particle production in elementary proton-proton
collisions at RHIC energies. Comparison to leading order and next-to-leading
order (NLO) calculations shows that the fragmentation process is flavor
dependent and that higherorder corrections are needed to describe all spectra,
in particular at these collision energies, which are modest compared to the
Tevatron energies. A model (EPOS) which takes into account multiple scattering
between projectile constituents seems to describe the data best.Comment: 4 pages, 4 figures, QM2005 poster proceedings, updated according to
referee repor
Formation and decay of hadronic resonances in the QGP
Hadronic resonances can play a pivotal role in providing experimental
evidence for partial chiral symmetry restoration in the deconfined quark-gluon
phase produced at RHIC. Their lifetimes, which are comparable to the lifetime
of the partonic plasma phase, make them an invaluable tool to study medium
modifications to the resonant state due to the chiral transition. In this paper
we show that the heavier, but still abundant, light and strange quark
resonances K*, phi, Delta and Lambda* have large probability to be produced
well within the plasma phase due to their short formation times. We demonstrate
that, under particular kinematic conditions, these resonances can be formed and
will decay inside the partonic state, but still carry sufficient momentum to
not interact strongly with the hadronic medium after the QCD phase transition.
Thus, K*, phi, Delta and Lambda* should exhibit the characteristic property
modifications which can be attributed to chiral symmetry restoration, such as
mass shifts, width broadening or branching ratio modifications.Comment: 8 pages, 7 figure
Fluctuations and correlations in high temperature QCD
We calculate second- and fourth-order cumulants of conserved charges in a
temperature range stretching from the QCD transition region towards the realm
of (resummed) perturbation theory. We perform lattice simulations with
staggered quarks; the continuum extrapolation is based on in
the crossover-region and at higher temperatures. We find that
the Hadron Resonance Gas model predictions describe the lattice data rather
well in the confined phase. At high temperatures (above 250 MeV) we find
agreement with the three-loop Hard Thermal Loop results.Comment: 18 pages revtex, 13 figure
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