Related papers: Successes and failures with hard probes
We consider the $J/\Psi$ suppression at a high energy heavy ion collision. An ideal gas of massive hadrons in thermal and chemical equilibrium is formed in the central region. The finite-size gas expands longitudinally in accordance with…
We have studied the J/psi suppression in 158 GeV/c Pb+Pb collisions at CERN SPS. J/psi production is assumed to be a two step process, (i) formation of c bar{c} pair, which is accurately calculable in QCD and (ii) formation of J/psi meson…
We first discuss, on a no-QGP basis, the two prominent indications of (a) enhanced strangeness production and of (b) anomalous $J/\psi $-suppression: We elaborate in particular on a recent idea of antihyperon production solely by…
We investigate J/\psi transverse-momentum (p_t) distributions and their centrality dependence in heavy-ion collisions at SPS and RHIC within the framework of a two-component model, which includes (i) primordial production coupled with…
The momentum dependence of the exciting new Pb + Pb data from LHC qualitatively suggests a perturbative picture interpretation for the energy loss of high-pT particles, but conclusions are difficult to draw due to the lack of 1) a…
Quarkonium is an ideal probe to explore the properties of quantum chromodynamics (QCD). Unlike Large Hadron Collider (LHC) measurements, quarkonium production at the Relativistic Heavy Ion Collider (RHIC) has different production…
The thermal suppression of heavy quark bound states represents an ideal observable for determining if one has produced a quark-gluon plasma in ultrarelativistic heavy-ion collisions. In recent years, a paradigm shift has taken place in the…
In the last 20 years, heavy-ion collisions have been a unique way to study the hadronic matter in the laboratory. Its phase diagram remains unknown, although many experimental and theoretical studies have been undertaken in the last…
The Relativistic Heavy Ion Collider (RHIC) was built to re-create and study in the laboratory the extremely hot and dense matter that filled our entire universe during its first few microseconds. Its operation since June 2000 has been…
Identified-hadron (PID) spectra from 2.76 TeV Pb-Pb and $p$-$p$ collisions are analyzed via a two-component (soft + hard) model (TCM) of hadron production in high-energy nuclear collisions. The Pb-Pb TCM is adopted with minor changes from a…
J/psi suppression induced by color screening of its constituent quarks was proposed 26 years ago as a signature of the formation of a quark gluon plasma in heavy-ion collisions. Recent results from ALICE in Pb-Pb collisions exhibit a…
We demonstrate that it is possible to use the polarization of vector quarkonia, measured from dilepton event samples, as an instrument to study the suppression of chi_c and chi_b in heavy-ion collisions, where a direct determination of…
One of the key signatures of the Quark-Gluon Plasma (QGP), is the modification of hadron transverse momentum differential cross-sections in heavy-ion collisions (HIC) as compared to proton-proton (pp) collisions. Suppression of hadron…
The proposed sPHENIX detector at RHIC is being designed to study with unprecedented precision the nature of the Quark Gluon Plasma, or QGP, at RHIC through measurement of jets, jet correlations, and Y particles. To reach the goal of…
Recent experimental measurements of high $p_T$ hadron spectra and jet correlation at RHIC are analyzed within a parton model which incoporates initial jet production and final propagation in heavy-ion collisions. The suppresion of single…
The medium-modifications of processes characterized by the presence of a hard scale provide the most diverse tools to characterize the properties of the matter created in high-energy nuclear collisions. Indeed, jet quenching, the…
We calculate and compare bremsstrahlung and collisional energy loss of hard partons traversing a quark-gluon plasma. Our treatment of both processes is complete at leading order in the coupling and accounts for the probabilistic nature of…
Single electrons from open heavy quarks and di-leptons from J/psi mesons have been studied systematically at RHIC/PHENIX using data from p + p, d + Au and Au + Au collisions at $\sqrt{s_{NN}}$ = 62.4 GeV, 130 GeV and 200 GeV. From the…
I review some important results from RHIC experiments. They were obtained in a unique environment for studying QCD bulk matter at temperatures and densities that surpass the limits where hadrons can exist as individual entities, raising the…
We present new results of a completed PHENIX analysis of $\psi(2s)$ modification at midrapidity in 200 GeV $d+$Au collisions. Strong suppression of the $\psi(2s)$ relative to the $J/\psi$ is observed. This difference in suppression is too…