Related papers: Nuclear modification of hard scattering processes …
Recent results on high transverse momentum (pT) hadron production in p+p, d+Au and Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC) are reviewed. Comparison of the nuclear modification factors, $R_{dAu}(pT)$ and $R_{AA}(pT)$,…
Small nuclear collisions are mainly sensitive to cold-nuclear-matter effects; however, the collective behavior observed in these collisions shows a hint of hot-nuclear-matter effects. The identified-particle spectra, especially the $\phi$…
Nuclear modification factors for pion production in AuAu and CuCu collisions are analyzed at very high transverse momenta. At p_T > 10 GeV/c, the R_{AA}(p_T) is determined mostly by the initial state nuclear modifications (e.g. EMC effect)…
We study the effect of nuclear matter in Upsilon production in dAu collisions at RHIC and pPb collisions at the LHC. We find that the nuclear modification factor, R^Upsilon_dAu, measured at RHIC is not satisfactorily reproduced by the…
Recently it has become apparent that event-by-event fluctuations in the initial state of hydrodynamical modelling of ultrarelativistic heavy-ion collisions are crucial in order to understand the full centrality dependence of the elliptic…
Identified mid-rapidity particle spectra of $\pi^{\pm}$, $K^{\pm}$, and $p(\bar{p})$ from 200 GeV p+p and d+Au collisions are reported. This data were taken in 2003 run from the Solenoidal Tracker at RHIC (STAR) experiment. A time-of-flight…
This article is based on my Proceedings for the 47th Course of the International School of Subnuclear Physics on the Most Unexpected at LHC and the Status of High Energy Frontier, Erice, Sicily, Italy, 2009. Results from the PHENIX…
Hadrons carrying heavy quarks, i.e. charm or bottom, are important probes of the hot and dense medium created in relativistic heavy ion collisions. Heavy quark-antiquark pairs are mainly produced in initial hard scattering processes of…
The PHENIX experiment has measured {\piz}s in Au+Au collisions at sqrt(s_{NN}) = 200 GeV, with good statistics for transverse momentum, pT, up to 20 GeV/c. A fivefold suppression is found, which is essentially constant for 5<pT<20 GeV/c.…
In a pQCD-based model, we have analyzed the STAR data on the high $p_T$ suppression of charged hadrons, in Au+Au collisions at $\sqrt{s}$=200 GeV. In the jet quenching or the energy loss picture, $p_T$ spectra of charged hadrons as well as…
There is a major need to better constrain nuclear parton densities in order to provide reliable perturbative QCD predictions at the LHC as well as to probe possible non-linear evolution at small values of x. In these proceedings, we discuss…
We calculate the spectra of high energy photons emitted in relativistic Au+Au collisions for various centralities and compare to data recently collected at the Relativistic Heavy Ion Collider by the PHENIX collaboration. Our results for…
The first evidence of jet quenching was observed at RHIC via suppression of single high $p_T$ hadron $R_{AA}$ and the disappearance of the away-side jet peak in two-particle correlations. Since then, hadron $R_{AA}$ and two-particle…
Centrality definition in A$+$A collisions at colliders such as RHIC and LHC suffers from a correlated systematic uncertainty caused by the efficiency of detecting a p$+$p collision ($50\pm 5\%$ for PHENIX at RHIC). In A$+$A collisions where…
Collisions of simple systems, such as $p$+$p$, or $p$+Nucleus have been used as benchmarks for our understanding of heavy ion collsions, since it was assumed they would be free of the effects from hot nuclear matter. Recently long range…
We report the observation at the Relativistic Heavy Ion Collider (RHIC) of suppression of back-to-back correlations in the direct photon+jet channel in Au+Au relative to p+p collisions. Two-particle correlations of direct photon triggers…
RHIC-PHENIX has observed a large suppression pattern and azimuthal anisotropy of non-photonic electron at mid-rapidity ($\mid\eta\mid<0.35$) in Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV. To understand these results and the interaction…
We present the preliminary results from our analysis of event by event fluctuation in K/pi ratio in Au+Au collision at \sqrt s_{NN} = 200 GeV and at 62.4 GeV using STAR detector at RHIC. Two different methods have been used to extract the…
The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) has measured electrons from heavy flavor (charm and bottom) decays for 0.3 < p_T < 9 GeV/c at midrapidity (|y| < 0.35) in Au+Au collisions at sqrt(s_NN) = 200 GeV. The…
Results of resonance particle production measured at RHIC in $\sqrt{s_{\rm NN}} = $ 200 GeV Au+Au collisions are compared to measurements in p+p and d+Au collisions in order to verify the existence of an extended hardronically interacting…