877 research outputs found
Centrality dependence of the ratios and - a test of thermalization in Au+Au collisions at RHIC
We present the centrality dependence of the ratios and
measured in Au+Au collisions at GeV by the
STAR experiment at RHIC. The results are compared to measurements of other
identified particles and recombination model expectations in order to gain
insight into the partonic collectivity and possible thermalization of the
produced medium.Comment: 4 pages, 2 figures, Quark Matter 2006 conference proceeding
Resonance Studies at STAR
We report on the observed signals of and
using the mixed-event method with powerful
statistics from the large acceptance and highly efficient STAR TPC. Preliminary
results from the first observation of such states from the year-one STAR data
in GeV Au-Au collisions are presented. The
ratios with an assumed inverse slope of
300MeV are compatible with that from pp at ISR. For 14% central Au+Au
collisions, we observe and
. We show that
from this method is consistent with
the measurement via decay topology.Comment: 4 pages, 4 figures, Quark Matter 2001, contributed talk; typos of
K*/h- numbers in abstract fixe
Antinucleus Production at RHIC
Light antinuclei may be formed in relativistic heavy ion collisions via final
state coalescence of antinucleons. The yields of antinuclei are sensitive to
primordial antinucleon production, the volume of the system at kinetic
freeze-out, and space-momentum correlations among antinucleons at freeze-out.
We report here preliminary STAR results on antideuteron and antihelion
production in 130A GeV Au+Au collisions. These results are examined in a
coalescence framework to elucidate the space-time structure of the antinucleon
source.Comment: 4 pages, 3 figures, talk given at Quark Matter 200
Spin physics with STAR
The STAR collaboration aims to study polarized proton-proton collisions at
RHIC. The emphasis of the spin run this year is on transverse single spin
asymmetries. Beyond 2001, we aim to determine directly and precisely the gluon
polarization, as well as the polarizations of the u, , d and
quarks in the proton by measuring in addition longitudinal and double spin
asymmetries. Furthermore, we aim to measure for the first time the quark
transversity distributions. These measurements will improve substantially the
knowledge and understanding of the spin structure of the nucleon.Comment: 9 pages, 3 figures. Talk presented at The 3rd Circum-Pan-Pacific
Symposium on "High Energy Spin Physics" October 8-13 2001, Beijing, Chin
Elliptic flow in Au+Au collisions at = 130 GeV
We report the elliptic flow of charged and identified particles at
mid-rapidity in Au+Au collisions at GeV using the STAR
TPC at RHIC. The integrated elliptic flow signal, , for charged particles
reaches values of about 0.06, indicating a higher degree of thermalization than
at lower energies. The differential elliptic flow signal, () up to
1.5 GeV/, shows a behavior expected from hydrodynamic model calculations.
Above 1.5 GeV/, the data deviate from the hydro predictions; however the
() is still large, suggesting finite asymmetry for the products of
hard scattering. For the identified particles, elliptic flow as a function of
and centrality differ significantly for particles of different masses.
This dependence can be accounted for in hydrodynamic models, indicating that
the system created shows a behavior consistent with collective hydrodynamical
flow.Comment: 6 pages, 8 figures, Quark Matter 200
Teaching Excellence Framework: Analysis of highly skilled employment outcomes: Research report: September 2016
Measurements of Photon and Neutral Pion Production in Heavy Ion Collisions at RHIC
Inclusive transverse momentum spectra of photons and neutral pions about
mid-rapidity are presented for Au+Au collisions at sqrt(s_NN} = 130 GeV. Photon
pair conversions have been reconstructed from charged tracks measured with the
central Time Projection Chamber (TPC) of STAR. Contributions of the pi^0 ->
\gamma\gamma decay in the inclusive photon spectra have been studied. It was
found that this contribution begins to decrease at a transverse momentum of
1.65 GeV/c in the top 11% most central centrality class.Comment: 5 pages, 3 figures, contribution to the Proceedings of Quark Matter
2002, Nantes, France, July 18-24, 200
Baryon and antibaryon production in hadron-hadron and hadron-nucleus interactions
Cascade baryon and anti-baryon yields have been measured in p+p and p+A
collisions. After extraction of the projectile component in p+A interactions
close similarities with A+A collisions concerning the nuclear enhancement
factors are observed. In addition the importance of effects related to
projectile isospin and to net baryon stopping is pointed out.Comment: 4 pages, 5 figures, Presented at Quark Matter 2002, Nantes, Franc
Elementary Hadronic Interactions at the CERN SPS
New data from the NA49 experiment at the CERN SPS concerning hadron+proton
and hadron+nucleus interactions are discussed and compared to nucleus+nucleus
collisions. Detailed information on baryonic momentum distributions and nuclear
enhancement factors for kaons and cascade baryons are extracted.Comment: 11 pages, 9 figures, to be published in the Proceedings of the XVIth
International Conference on Ultrarelativistic Nucleus-Nucleus Collisions
"Quark Matter 2002", Nantes, France, July 200
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