2,392 research outputs found
Central Coulomb Effects on Pion Interferometry
Using a simple final-state rescattering model coupled with a simple Coulomb
model, the effects of the central Coulomb potential on pion interferometry
measurements in 158 GeV/nucleon Pb+Pb collisions are explored. Although the
central Coulomb potential does not introduce correlations between pions, it
does prevent an accurate measurement of the momentum difference. This momentum
difference smearing effect leads to a reduction in the measured correlation
radii and lambda parameters. These distortions are important in 158 GeV/nucleon
Pb+Pb collisions because of large source sizes and the strong central Coulomb
potential.Comment: 6 pages, Latex, 2 postscript figure
Signatures for flow effects in s**(1/2) = 200 GeV proton-proton collisions
A simple model based on relativistic geometry and final-state hadronic
rescattering is used to predict pion source parameters extracted in two-pion
femtoscopy studies of proton-proton collisions at s**(1/2) = 200 GeV. From
studying the momentum and particle multiplicity dependences of these parameters
in the context of this model and assuming a very short hadronization time,
flow-like behavior is seen which resembles the flow behavior commonly observed
in relativistic heavy-ion collisions.Comment: 10 pages, 3 figures, submitted to Physical Revie
Effects of non-causal artifacts in a hadronic rescattering model for RHIC collisions
It has been shown that calculations based on a hadronic rescattering model
agree reasonably well with experimental results from RHIC Au+Au collisions.
Because of the large particle densities intrinsically present at the early time
steps of Monte Carlo calculations attempting to model RHIC collisions
undesirable artifacts resulting in non-causality may be present. The effects of
such artifacts on observables calculated from the rescattering model are
studied in the present work in two ways: 1) varying the time step and 2) using
the subdivision method. It is shown that although non-causal artifacts are
present in the rescattering model they have no appreciable effects on the
calculated observables, thus strengthing the confidence in the results of this
rescattering model for RHIC energies.Comment: 14 pages, 8 figure
K0s-K0s correlations in 7 TeV pp collisions from the ALICE experiment at the LHC
Identical neutral kaon pair correlations are measured in 7 TeV pp collisions
in the ALICE experiment. K0s-K0s correlation functions are formed in 3
multiplicity X 4 kT bins. The femtoscopic kaon source parameters Rinv and
lambda are extracted from these correlation functions by fitting a (femtoscopy)
X (PYTHIA) model to them, PYTHIA accounting for the non-flat baseline found in
pp collisions. Source parameters are obtained from a fit which includes quantum
statistics and final-state interactions of the a0/f0 resonance. K0s-K0s
correlations show a systematic increase in Rinv for increasing multiplicity bin
and decreasing Rinv for increasing kT bin as seen in pi-pi correlations in the
pp system, as well as seen in heavy-ion collisions. Also, K0s-K0s correlations
are observed to smoothly extend this pi-pi Rinv behavior for the pp system up
to about three times higher kT than the kT range measured in pi-pi
correlations.Comment: Proceedings of the Quark Matter 2011 Conference, 4 pages, 5 figure
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