Related papers: Cold Nuclear Matter effects in Upsilon production …
We present the analysis of $\Upsilon\to e^{+}e^{-}$ production in d+Au collisions at $\sqrt{s_{NN}} = 200$ GeV from the STAR experiment. Using higher level dedicated $\Upsilon$ triggers, STAR has sampled 32 nb$^{-1}$ of integrated…
The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) has measured $\phi$ meson production and its nuclear modification in asymmetric Cu$+$Au heavy-ion collisions at $\sqrt{s_{NN}}=200$ GeV at both forward Cu-going direction…
During the 2008 run RHIC provided high luminosity in both p+p and d+Au collisions at $\sqrt{s_{NN}}=200GeV$. Electromagnetic calorimeter acceptance in STAR was enhanced by the new Forward Meson Spectrometer (FMS), and is now almost…
Effects of strangeness on nuclear modification in d-Au and Au-Au collisions at 200 GeV are studied, in order to quantify the effects of quark content and mass. Measurements of ratios of the yields in central collisions to the yields in…
The density of gluons produced in the central rapidity region of a heavy ion collision is poorly known. We investigate the influence of the effects of quantum coherence on the transverse momentum distribution of photons and gluons radiated…
We calculate nuclear modification factors $R_{dAu}$, central-to-peripheral ratios, $R_{CP}$, and pseudorapidity asymmetries $Y_{Asym}$ in deuteron-gold collisions at $\sqrt{s} = 200$ GeV in the framework of leading-order (LO) perturbative…
Prompt photons produced in a hard reaction are not accompanied with any final state interaction, either energy loss or absorption. Therefore, besides the Cronin enhancement at medium transverse momenta pT and small isotopic corrections at…
We review recent measurements of high transverse momentum (high $p_T$) hadron production in nuclear collisions by the STAR Collaboration at RHIC. The previously observed suppression in central Au+Au collisions has been extended to much…
High energy lepton scattering has been the primary tool for mapping out the quark distributions of nucleons and nuclei. Data on the proton and deuteron have shown that there is a fundamental connection between the low and high energy…
We investigate the {\Upsilon} production in heavy ion collisions at LHC energy in the frame of a dynamical transport approach. Both the initial production and in-medium regeneration and both the cold and hot nuclear matter effects are…
In this study, the chemical freeze-out of hadrons, including light-and strange-flavor particles and light nuclei, produced in Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC), was investigated. Using the thermal-FIST…
Nuclear modification factor ($R_{cp}$) of protons and pions are investigated by simulating Au + Au collisions from 0.8 to 1.8$A$ GeV in a framework of an isospin-dependent quantum molecular dynamics (IQMD) model. $R_{cp}$ of protons rises…
We take hydrodynamic initial conditions in relativistic heavy ion collisions from the Color Glass Condensate (CGC) picture through the kT factorization formula. Gluon distributions produced from the CGC are found to provide good initial…
For central heavy ion collisions at the RHIC energy, the entropy per unit rapidity dS/dy at freeze-out is extracted with minimal model dependence from available experimental measurements of particle yields, spectra, and source sizes…
The assumption of factorization lies at the core of calculations of medium effects on observables computable in perturbative Quantum Chromodynamics. In this work we examine this assumption, for which we propose a setup to study hard…
We study the associated production of $ J/\psi\ + \gamma $ in fixed-target experiments with nuclear targets as well as at the relativistic heavy-ion collider (RHIC). We find that this process affords a very clean probe of $\rho_g$, the…
Medium effects on the production of high-$p_{\rm T}$ particles in nucleus-nucleus (AA) collisions are generally quantified by the nuclear modification factor ($R_{\rm AA}$), defined to be unity in absence of nuclear effects. Modeling…
Heavy flavor production in hadronic collisions is dominated by gluonic processes and so is a sensitive probe of the gluon structure function in the nucleon and its modification in nuclei. A study of heavy flavor production in p+p and d+Au…
In the jet quenching model, we have analysed the PHENIX data on nuclear modification factor of $\pi^0$, in Au+Au collisions at $\sqrt{s}$=200 GeV, and extracted the initial gluon density of the medium produced. In jet quenching, partons…
We have carried out a wide study of shadowing and antishadowing effects on \jpsi\ production in \dAu\ collisions at $\sqrt{s_{NN}}=200$ GeV. We have studied the effects of three different gluon nPDF sets, using the exact kinematics for a…