Jets as a probe of dense matter at RHIC

Abstract

Jet quenching in the matter created in high energy nucleus-nucleus collisions provides a tomographic tool to probe the medium properties. Recent experimental results on jet production at the Relativistic Heavy-Ion Collider (RHIC) are reviewed. Jet properties in p+p and d+Au collisions have been measured, establishing the baseline for studying jet modification in heavy-ion collisions. Current progress on detailed studies of high transverse momentum production in Au+Au collisions is discussed, with an emphasis on dihadron correlation measurements.

What have we learned at RHIC?

“…The quantitative analysis [11,12] of R AA as well as the suppression of away-side jets from the centrality dependence of dihadron correlations I AA ( φ, b ) provides important consistency checks of the jet tomographic analysis of the QGP initial conditions. An exciting preliminary STAR analysis (see [49]) finds, e.g., an azimuthal angle dependence of away-side correlations relative to the collective reaction plane as expected from jet tomography.…”

Azimuthally sensitive correlations in nucleus-nucleus collisions

“…In particular, it results * Electronic address: borghini@spht.saclay.cea.fr † Electronic address: Ollitrault@cea.fr in a modification of the pattern of azimuthal correlations between high-p T hadrons, compared to pp collisions: the back-to-back correlation is suppressed [17,18]. In a non-central collision, the average length of matter traversed by a parton depends on its azimuth [19,20], which results in azimuthally dependent two-particle correlations [21,22].…”

Dihadron correlations at highpT

“…Recent high p T measurements performed with d+Au collisions [6][7][8][9] confirm that the nuclear attenuation observed in central Au+Au collisions is due to final-state interactions of jets in the dense matter formed in heavy-ion collisions. A comprehensive review of the RHIC data and theory is given in [10], while most recent experimental results on jet production at RHIC are summarized in [11]. I will review the dihadron correlation measurements at high p T at the top RHIC energy ( √ s NN = 200 GeV)…”