278 research outputs found
Two and Three Particle Flavor Dependent Correlations
The PHENIX collaboration has developed novel methodologies for reliable
extraction of jet functions from two and three particle azimuthal correlation
functions measured at mid-rapidity in Au+Au collisions at GeV.
The extracted jet shape and the yield of jet-associated partner hadrons (per
trigger hadron) are found to vary with particle type and collision centrality,
indicating a significant effect of the nuclear collision medium on the (di)jet
fragmentation process.Comment: Proceedings for Quark Matter 2005 parallel tal
Identification of exotic jet topologies via three particle correlations in PHENIX
Modifications of jet properties resulting from the coupling of jets to the
strongly interacting matter produced in RHIC collisions are of great current
interest. In recent work, the PHENIX collaboration has applied a novel
technique to the analysis of two particle azimuthal correlations which
extinguishes the harmonic part of the underlying event revealing the true jet
shape. Recent extensions of the method to three particle correlations allow for
a more revealing study of jet topologies in Au+Au collisions at
(=200 GeV).Comment: Poster presented at Quark Matter 200
Extraction of jet topology using three particle correlations
Recent theoretical studies have indicated that the topological features of
away-side jet fragments can be significantly altered by medium-induced
modifications. The leading candidates resulting from such modifications are
Mach Cones and deflected jets. We show that three particle correlations are
able to distinguish between these different modification scenarios. Initial
results from an application of the method to Au+Au collisions at RHIC
( GeV) are presented.Comment: 4 pages, 3 figs. Proceedings 2nd International Conference on Hard and
Electromagnetic Probes of High-Energy Nuclear Collisions, June 9-16, 2006,
Asilomar, Pacific Grove, Californi
Anisotropic flow in 4.2A GeV/c C+Ta collisions
Anisotropic flow of protons and negative pions in 4.2A GeV/c C+Ta collisions
is studied using the Fourier analysis of azimuthal distributions. The protons
exhibit pronounced directed flow. Directed flow of pions is positive in the
entire rapidity interval and indicates that the pions are preferentially
emitted in the reaction plane from the target to the projectile. The elliptic
flow of protons and negative pions is close to zero. Comparison with the
quark-gluon-string model (QGSM) and relativistic transport model (ART 1.0) show
that they both yield a flow signature similar to the experimental data.Comment: 4 pages, 3 figures, Accepted for publication in Phys. Rev.
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
Transverse Spin at PHENIX: Results and Prospects
The Relativistic Heavy Ion Collider (RHIC), as the world's first and only
polarized proton collider, offers a unique environment in which to study the
spin structure of the proton. In order to study the proton's transverse spin
structure, the PHENIX experiment at RHIC took data with transversely polarized
beams in 2001-02 and 2005, and it has plans for further running with transverse
polarization in 2006 and beyond. Results from early running as well as
prospective measurements for the future will be discussed.Comment: 6 pages, 2 figures, presented at Transversity 2005, Como, Ital
Cross section for bb over-bar production via dielectrons in d+Au collisions at root √sNN=200 GeV
Measurement of the higher-order anisotropic flow coefficients for identified hadrons in Au + Au collisions at √sNN =200 GeV
Measurement of the relative yields of ψ(2S) to ψ(1S) mesons produced at forward and backward rapidity in p+p, p+Al, p+Au, and 3He+Au collisions at √sNN=200 GeV
The PHENIX Collaboration has measured the ratio of the yields of to mesons produced in , Al, Au, and HeAu collisions at GeV over the forward and backward rapidity intervals . We find that the ratio in collisions is consistent with measurements at other collision energies. In collisions with nuclei, we find that in the forward (-going or He-going) direction, the relative yield of mesons to mesons is consistent with the value measured in \pp collisions. However, in the backward (nucleus-going) direction, the is preferentially suppressed by a factor of 2. This suppression is attributed in some models to breakup of the weakly-bound through final state interactions with comoving particles, which have a higher density in the nucleus-going direction. These breakup effects may compete with color screening in a deconfined quark-gluon plasma to produce sequential suppression of excited quarkonia states
Multi-particle azimuthal correlations for extracting event-by-event elliptic and triangular flow in Au+Au collisions at √sNN = 200 GeV
We present measurements of elliptic and triangular azimuthal anisotropy of charged particles detected at forward rapidity 1 < |η| < 3 in Au+Au collisions at √sNN = 200 GeV, as a function of centrality. The multiparticle cumulant technique is used to obtain the elliptic flow coefficients v2{2}, v2{4}, v2{6}, and v2{8}, and triangular flow coefficients v3{2} and v3{4}. Using the smallvariance limit, we estimate the mean and variance of the event-by-event v2 distribution from v2{2} and v2{4}. In a complementary analysis, we also use a folding procedure to study the distributions of v2 and v3 directly, extracting both the mean and variance. Implications for initial geometrical fluctuations and their translation into the final state momentum distributions are discusse
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