209 research outputs found
Identified Particle Jet Correlations from PHENIX
Two-particle azimuthal correlations have been shown to be a powerful probe
for extracting novel features of the interaction between hard scattered partons
and the medium produced in Au+Au collisions at RHIC. At intermediate ,
2-5GeV/c, jets have been shown to be significantly modified in both particle
composition and angular distribution compared to p+pcollisions. We present
recent PHENIX results from Au+Au collisions for a variety of and particle
combinations.Comment: Parallel talk given at Quark Matter 2006, Shanghai Chin
PHENIX measurement of jet properties and their modification in heavy-ion collisions
The properties of jets produced in p+p, d+Au and Au+Au collisions at
sqrt{s_NN}=200 GeV are studied using the method of two particle correlations.
The trigger particle is assumed to be a leading particle from a high p_T jet
while the associated particle is assumed to come from either the same jet or
the away jet. From the angular width and yield of the same and away side
correlation peaks, the parameters characterizing the jet properties are
extracted.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
Hadron production in the forward and backward rapidities in dAu collisions at RHIC
We have developed new techniques to detect hadrons with the PHENIX muon
spectrometers. This allows us to study the centrality dependent nuclear
modification factor with high hadrons in both forward (d
direction) and backward (Au direction) rapidities, , in dAu
collisions at . Preliminary results show a suppression
(enhancement) of high hadron production in central dAu
collisions relative to the peripheral one ( in centrality) at forward
(backward) rapidity.Comment: 4 pages, 4 figures, Quark Matter 2004 tal
Neutral Pion Distributions in PHENIX at RHIC
Transverse momentum spectra for identified 's in the range 1 GeV/c 4 GeV/c have been measured by the PHENIX experiment in Au-Au collisions
at GeV. The spectra from peripheral nuclear collisions are
consistent with the simple expectation of scaling the spectra from p+p
collisions by the average number of nucleon-nucleon binary collisions. The
spectra from central collisions and the ratio of central/peripheral spectra are
significantly suppressed when compared to point-like scaling.Comment: 6 pages, 3 figure
Results on Photon Production in Au+Au Collisions at RHIC
The status of the search for direct photons in Au+Au collisions at sqrt{s_NN}
= 130 GeV and sqrt{s_NN} = 200 GeV with the PHENIX experiment is presented.
Within errors, no excess of direct photons was found in a first analysis pass
done on a limited data set. Significantly reduced systematic and statistical
uncertainties are expected in future analyses.Comment: 4 pages, 3 figures. Talk presented at the Quark Matter 2002
conference, Nantes, France, July 18-24, 2002. To appear in the proceedings
(Nucl. Phys. A
Two Particle Azimuthal Correlation Measurements in PHENIX
Two particle azimuthal correlation functions are presented for charged
hadrons produced in Au-Au collisions at RHIC sqrt(s_NN)=200 GeV.The correlation
functions indicate sizeable asymmetries and anisotropies. The trend of the
asymmetries is compatible with the presence of emission patterns associated
with mini-jets. The magnitude and the trend of the differential anisotropies
v_2(p_T) and v_2(N_Part), provide important model constraints.Comment: 4 pages 3 fig
Event Reconstruction in the PHENIX Central Arm Spectrometers
The central arm spectrometers for the PHENIX experiment at the Relativistic
Heavy Ion Collider have been designed for the optimization of particle
identification in relativistic heavy ion collisions. The spectrometers present
a challenging environment for event reconstruction due to a very high track
multiplicity in a complicated, focusing, magnetic field. In order to meet this
challenge, nine distinct detector types are integrated for charged particle
tracking, momentum reconstruction, and particle identification. The techniques
which have been developed for the task of event reconstruction are described.Comment: Accepted for publication in Nucl. Instrum. A. 34 pages, 23 figure
Proximity effect at superconducting Sn-Bi2Se3 interface
We have investigated the conductance spectra of Sn-Bi2Se3 interface junctions
down to 250 mK and in different magnetic fields. A number of conductance
anomalies were observed below the superconducting transition temperature of Sn,
including a small gap different from that of Sn, and a zero-bias conductance
peak growing up at lower temperatures. We discussed the possible origins of the
smaller gap and the zero-bias conductance peak. These phenomena support that a
proximity-effect-induced chiral superconducting phase is formed at the
interface between the superconducting Sn and the strong spin-orbit coupling
material Bi2Se3.Comment: 7 pages, 8 figure
Centrality Dependence of the High p_T Charged Hadron Suppression in Au+Au collisions at sqrt(s_NN) = 130 GeV
PHENIX has measured the centrality dependence of charged hadron p_T spectra
from central Au+Au collisions at sqrt(s_NN)=130 GeV. The truncated mean p_T
decreases with centrality for p_T > 2 GeV/c, indicating an apparent reduction
of the contribution from hard scattering to high p_T hadron production. For
central collisions the yield at high p_T is shown to be suppressed compared to
binary nucleon-nucleon collision scaling of p+p data. This suppression is
monotonically increasing with centrality, but most of the change occurs below
30% centrality, i.e. for collisions with less than about 140 participating
nucleons. The observed p_T and centrality dependence is consistent with the
particle production predicted by models including hard scattering and
subsequent energy loss of the scattered partons in the dense matter created in
the collisions.Comment: 7 pages text, LaTeX, 6 figures, 2 tables, 307 authors, resubmitted to
Phys. Lett. B. Revised to address referee concerns. Plain text data tables
for the points plotted in figures for this and previous PHENIX publications
are publicly available at
http://www.phenix.bnl.gov/phenix/WWW/run/phenix/papers.htm
Single Electrons from Heavy Flavor Decays in p+p Collisions at sqrt(s) = 200 GeV
The invariant differential cross section for inclusive electron production in
p+p collisions at sqrt(s) = 200 GeV has been measured by the PHENIX experiment
at the Relativistic Heavy Ion Collider over the transverse momentum range $0.4
<= p_T <= 5.0 GeV/c at midrapidity (eta <= 0.35). The contribution to the
inclusive electron spectrum from semileptonic decays of hadrons carrying heavy
flavor, i.e. charm quarks or, at high p_T, bottom quarks, is determined via
three independent methods. The resulting electron spectrum from heavy flavor
decays is compared to recent leading and next-to-leading order perturbative QCD
calculations. The total cross section of charm quark-antiquark pair production
is determined as sigma_(c c^bar) = 0.92 +/- 0.15 (stat.) +- 0.54 (sys.) mb.Comment: 329 authors, 6 pages text, 3 figures. Submitted to Phys. Rev. Lett.
Plain text data tables for the points plotted in figures for this and
previous PHENIX publications are (or will be) publicly available at
http://www.phenix.bnl.gov/papers.htm
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