126 research outputs found
Measurement of Open Heavy Flavor Production with Single Muons in p+p and d+Au Collisions at RHIC
Heavy flavor production in hadronic collisions is dominated by gluonic
processes and so is a sensitive probe of the gluon structure function in the
nucleon and its modification in nuclei. A study of heavy flavor production in
p+p and d+Au collisions in various kinematic regions presents an opportunity to
probe cold nuclear medium effects; parton shadowing, color glass condensate,
initial state energy loss, and coherent multiple scattering in final state
interactions. The PHENIX muon arms cover both forward and backward directions
in the rapidity range of . We investigate single muon
production from open heavy flavor and light mesons decay in p+p and d+Au
collisions at forward and backward rapidity.Comment: Strangeness in Quark Matter, 2006, UCL
Direct photons at low measured in PHENIX
Direct photon spectra measured at small in p+p, d+Au and Au+Au
collisions at GeV are presented. Several measurement
techniques including statistical subtraction, tagging, and internal and
external conversion were applied and found to produce consistent results. The
p+p and d+Au results are found to be in very good agreement with pQCD
predictions over the entire range. No excess of direct photons in Au+Au
collisions with respect to binary scaled d+Au data is observed within
systematic errors.Comment: 4 pages, 3 figures, proceedings for Quark Matter 200
PHENIX Studies of the Scaling Properties of Elliptic Flow at RHIC
Recent PHENIX elliptic flow () measurements for identified particles
produced in Au+Au and Cu+Cu collisions at GeV are presented
and compared to other RHIC measurements. They indicate universal scaling of
compatible with partonic collectivity leading to the flow of light,
strange and heavy quarks with a common expansion velocity field.Comment: Proceedings, Quark Matter 2006, Shanghai, Chin
The azimuthal anisotropy of electrons from heavy flavor decays in sqrt(s_NN) = 200 GeV Au-Au collisions by PHENIX
The transverse momentum dependence of the azimuthal anisotropy parameter
v_{2}, the second harmonic of the azimuthal distribution, for electrons at
mid-rapidity (|eta|<0.35) has been measured with the PHENIX detector in Au+Au
collisions at sqrt(s_NN) = 200 GeV with respect to the reaction plane defined
at high rapidities (|eta|=3-4). From the result we have calculated non-photonic
electron v_{2}, which is expected to reflect the heavy-flavor azimuthal
anisotropy, by subtracting v_{2} of electrons from other sources such as photon
conversions, Dalitz decay etc.Comment: 4 pages, 4 figures, proceeding (poster) of the 18th International
Conference on Nucleus-Nucleus Collisions (QM2005), Aug.4-9, Budapest, Hungar
The PHENIX measurement of Heavy Flavor via Single Electrons in pp, d-Au, and Au-Au collisions at sqrt(s_NN)=200 GeV
The PHENIX experiment at RHIC has measured single electron spectra in
proton-proton, deuteron-gold and gold-gold collisions at sqrt(s_NN)=200 GeV.
The photonic contribution (photon conversions and Daltiz decays) is subtracted
from the inclusive spectra resulting in non-photonic electron spectra. The
principal source of non-photonic electrons is the semi-leptonic decay of charm
and bottom mesons. The implications for heavy flavor production in hot and cold
nuclear systems are discussed.Comment: 4 pages, 4 figures, contribution to the proceedings of the 17th
International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions
(Quark Matter 2004
Event anisotropy of identified , photon and electron compared to charged , , and deuteron in = 200 GeV Au+Au at PHENIX
We report the recent results of event anisotropy analysis focused on in
= 200 GeV Au+Au collisions at PHENIX.Comment: 4 pages, 3 figures, contribution to the proceedings of the 17th
International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions
(Quark Matter, Oakland, January 11-17, 2004). To appear in the proceedings
(Journal of Physics G
Evolution of the Away-Side Jet Shapes in pi0-h Correlations in 200 GeV Au+Au Collisions with RHIC-PHENIX
Two-particle azimuthal correlations have allowed detailed study of the
modification to di-jets in the hot, dense medium created in RHIC collisions.
Light can be shed by such correlations on many novel effects discovered at RHIC
such as the enhanced p/pi ratio and conical structure of events with energy
loss. Using pi0 triggers to reduce the effect of recombination we utilize
high-pT correlations to explore the away-side structure.Comment: 5 pages, 3 figures, poster presented at the 19th International
Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (QM2006
Probing gluon polarization with pi0's in longitudinally polarized proton collisions at the RHIC-PHENIX experiment
This report presents double helicity asymmetry in inclusive
production in polarized proton-proton collisions at a center-of-mass energy
() of 200 GeV. The data were collected with the PHENIX detector at
the Relativistic Heavy Ion Collider (RHIC) during the 2004 run. The data are
compared to a next-to-leading order perturbative quantum chromodynamic (NLO
pQCD) calculation.Comment: 4pp. To appear in the proceedings of 16th International Spin Physics
Symposium (SPIN 2004), Trieste, Italy, 10-16 Oct 200
Excitation functions of baryon anomaly and freeze-out properties at RHIC-PHENIX
The intermediate region (2 - 5 GeV/) in central Au+Au collisions at
RHIC has a rich physics content. The (anti)proton to pion ratio at the
intermediate gives us a powerful tool to investigate the bulk properties
of the hot and dense matter created at RHIC and their hadronization processes.
We present the preliminary results of identified charged hadron spectra at the
lower beam energies at RHIC. The excitation function of (anti)proton to pion
ratios from SPS to RHIC are shown. We also discuss the onset of the baryon
enhancement at the high energy heavy ion collisions.Comment: 4 pages, 3 figures, Quark Matter 2006 conference proceeding
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