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 $\sqrt s=200$ 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 ($\sqrt{s_{_{\rm NN}}}$=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 ($\sqrt{s_{NN}}=200$ 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

A New Correlator to Detect and Characterize the Chiral Magnetic Effect

A charge-sensitive in-event correlator is proposed and tested for its efficacy to detect and characterize charge separation associated with the Chiral Magnetic Effect (CME) in heavy ion collisions. Tests, performed with the aid of two reaction models, indicate discernible responses for background- and CME-driven charge separation, relative to the second- ($\Psi_{2}$) and third-order ($\Psi_{3}$) event planes, which could serve to identify the CME. The tests also indicate a degree of sensitivity which would enable robust characterization of the CME via Anomalous Viscous Fluid Dynamics (AVFD) model comparisons.Comment: 5 pages, 5 Figs.; Published versio

Modification of jet-like correlations in Pb-Au at the SPS

A high statistics study of high-$p_t$ two-particle azimuthal correlations in Pb-Au at $\sqrt{s_{\rm NN}}=17.2$ GeV, performed by the CERES experiment at the CERN-SPS, is presented. A broad away-side correlation with significant dip at $\Delta\phi\approx\pi$ is observed. The shape and magnitude of the correlation is similar to measurements at RHIC. In comparison to PYTHIA calculations, we observe a significant excess of soft particles at the away-side. A study of charge correlations between trigger and associated particles disfavors vacuum fragmentation of the away-side jet and suggests significant energy transfer of the hard-scattered parton to the medium.Comment: Proceedings to Quark Matter 2009 Conference, Knoxville, Tennessee, US

A new method for the experimental study of topological effects in the quark-gluon plasma

A new method is presented for the quantitative measurement of charge separation about the reaction plane. A correlation function is obtained whose shape is concave when there is a net separation of positive and negative charges. Correlations not specifically associated with charge, from flow, jets and momentum conservation, do not influence the shape or magnitude of the correlation function. Detailed simulations are used to demonstrate the effectiveness of the method for the quantitative measurement of charge separation. Such measurements are a pre-requisite to the investigation of topological charge effects in the QGP as derived from the "strong $\cal{CP}$ problem".Comment: Six pages 13 figures. Submitted for publicatio

Using two- and Three-particle correlations to probe strongly interacting partonic matter

The latest two- and three-particle correlation measurements obtained by the PHENIX collaboration are presented. Three-particle correlations are consistent with the presence of conical emission patterns in the data. Two-particle correlations relative to the collision geometry reveal strong shape and yield modifications of the away-side jet, that depend on the orientation of the trigger particle with respect to the event plane. A difference in the geometry dependence of the per trigger yields in the regions around $\Delta\phi \approx \pi$ and $\Delta\phi \approx \pi \pm 1.1$ can be understood by a different geometry dependence of jet energy loss and the medium response to the deposited energy.Comment: 4 pages, 3 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse