Gluon shadowing and jet quenching inA+Acollisions at √s=200AGeV

Abstract

The sensitivity of moderate /?r^8 GeV/c singles inclusive spectra in nuclear collisions to gluon shadowing and jet quenching is estimated using the HIJING Monte Carlo model. We show how the systematic study of the nuclear dependence of those spectra in p + A can be used to determine the magnitude of gluon shadowing and how the enhanced suppression in A +A would provide information on the energy loss mechanisms in dense partonic matter.

A comparative study of jet-quenching schemes

“…The number of such hadrons, irrespective of flavour, with p T ≥ 7GeV is reduced by almost a factor of 5 in central AuAu collisions compared to that expected from elementary nucleon nucleon encounters enhanced by the number of expected binary collisions [1,2]. This suppression, referred to as jet-quenching, caused by the energy loss of very energetic partons produced in the few hard scatterings that occur early in the collision, represents one of the major theoretical predictions which have been substantiated by experiment [3,4]. The basic underlying mechanism, that of induced gluon radiation from the hard parton traversing a coloured environment, has by now been expounded upon in multiple reviews [5,6] and there exists a certain consensus regarding the physics involved.…”

Highlights from STAR

“…High transverse momentum hadrons provide an excellent probe of the high energy density matter created at RHIC [4]. The measurement of particle yields and jet-like correlations at intermediate and high p T have demonstrated that indeed a hot and dense medium is created in Au+Au collisions at RHIC [5,6,7,8].…”

Multistage Monte Carlo simulation of jet modification in a static medium

“…The mass dependence of gluon emission from heavy quark is included in Eq. (8). In addition, t i denotes an "initial time" or the production time of the parent parton from which the gluon is emitted, and…”

“…With a selected scattering channel, the energies and momenta of the outgoing partons are then sampled based on the corresponding differential spectra given by Eq. (6) and (8). The only parameter in this LBT model is the strong coupling constant α s that quantifies the jet-medium interaction, which is determined by comparing model calculation to experimental data of single heavy and light flavor hadron production, single inclusive jet production and γ-jet production in heavy-ion collisions [31][32][33][34]51].…”

“…Jet modification [7][8][9][10][11][12][13][14][15][16][17], and its associated transport coefficients [18][19][20] provide multi-scale hard probes of the QGP. Jets start with an off-shellness or virtuality Q 2 that * Corresponding Authors is typically of the order of the hard scale, orders of magnitude higher than any scale in the medium.…”