Related papers: Direct photon production in d+A and A+A collisions…
When an energetic parton traversing the QCD medium, it may suffer multiple scatterings and lose energy. This jet quenching phenomenon may lead to the suppression of leading hadron productions as well as medium modifications of full jet…
To interpret the measurements in heavy-ion collisions at the Relativistic Heavy-Ion Collider (RHIC) it is crucial to understand the initial state of the colliding gold (Au) nuclei. The parton distribution in Au nuclei is modified compared…
The first measurement of direct photons in Au+Au collisions at sqrt(s_NN) = 200 GeV is presented. The direct photon signal is extracted as a function of the Au+Au collision centrality and compared to NLO pQCD calculations. The direct photon…
One of the important perturbative ("hard") probes of hot and dense QCD matter is the medium-induced energy loss of energetic partons, so called "jet quenching", which is predicted to be very different in cold nuclear matter and in QGP, and…
I present an overview of some of the recent results on jets and jet-like correlation measurements from the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory. Jets are produced in the initial hard scatterings of an…
Direct photons are important probes for quark gluon plasma created in high energy nuclear collisions. Various sources of direct photons in nuclear collisions are known, each of them endowed with characteristic information about the…
The PHENIX collaboration presents first measurements of low-momentum ($0.4<p_T<3$ GeV/$c$) direct-photon yields from Au$+$Au collisions at $\sqrt{s_{_{NN}}}$=39 and 62.4 GeV. For both beam energies the direct-photon yields are substantially…
Recent measurements of jet production rates at large transverse momentum ($p_T$) in the collisions of small projectiles with large nuclei at RHIC and the LHC indicate that they have an unexpected relationship with estimates of the collision…
The PHENIX experiment has measured direct photons at $\sqrt{s_{NN}}$ = 200 GeV in $p+p$, $d$+Au and Au+Au collisions. For $p_{T}$ $<$ 4 GeV/$c$, the internal conversion into $e^{+}e^{-}$ pairs has been used to measure the direct photons in…
The STAR Collaboration presents measurements of the semi-inclusive distribution of charged-particle jets recoiling from energetic direct-photon ($\gamma_{\rm dir}$) and neutral-pion ($\pi^{0}$) triggers in p+p and central Au+Au collisions…
We calculate the away-side hadron-triggered modification factor $I_{AA}$ in $AA$ collisions at RHIC and LHC energies for scenarios with and without quark-gluon plasma formation in $pp$ collision. We find that for both scenarios theoretical…
Jets are produced by processes involving high momentum transfer of initial partons at high energies. Comparing jet production in pp and nucleus-nucleus collisions will allow us to study the jet-quenching effect caused by the hot and dense…
A study of heavy flavor production in different collision systems in various kinematic regions presents an opportunity to probe cold nuclear medium and hot dense matter effects. Results from the PHENIX experiment on $J/\psi$ and open charm…
In this paper, a study of cold nuclear matter (CNM) effects is reported based on the new STAR measurement of inclusive $J/\psi$ production in $p+p$ and $p+\text{Au}$ collisions at $\sqrt{s_\text{NN}}$ = 200 GeV, and a combined…
Back-to-back light and heavy flavor dijet measurements are promising experimental channels to accurately study the physics of jet production and propagation in a dense QCD medium. They can provide new insights into the path length, color…
I discuss the systematic modifications to the perturbative QCD factorization approach in high energy l+A, p+A and A+A reactions. These include transverse momentum diffusion manifest in the Cronin effect and a small increase in the dijet…
We present the direct photon production for $1<p_{T}<10$ GeV/$c$ derived from continuum in the dielectron invariant mass region $0.1<M_{ee}<0.3$ GeV/$c^{2}$ from one billion $\sqrt{s_{NN}}=200$ GeV Au+Au events taken in year 2010 and 2011.…
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…
We update our calculations of thermal-photon production in nuclear collisions at the Relativistic Heavy-Ion Collider (RHIC). Specifically, we address the recent experimental observation of an elliptic flow of direct photons comparable in…
In this work, real photon production scattering kernels from jet-medium interactions in the QCD medium are perturbatively calculated using the higher-twist (HT) formalism. Focus is given towards real photon production from a highly virtual…