Related papers: Jet properties from direct $\gamma$ - hadron corre…
We point out that events associated with large $E_T$ direct photons in high-energy heavy-ion collisions can be used to study jet energy loss in dense matter. In such events, the $p_T$ spectrum of charged hadrons from jet fragmentation in…
The status of the search for direct photons in Au+Au collisions at sqrt{s_NN} = 130 GeV and sqrt{s_NN} = 200 GeV with the PHENIX experiment is presented. Within errors, no excess of direct photons was found in a first analysis pass done on…
When quarks hadronize, they accelerate. Because they carry electric charge, they must radiate light as they accelerate and hadronize. This is true not only in jets but also in heavy ion collisions, where a thermalized plasma of quarks and…
The properties of $\gamma$--jet pairs emitted in heavy-ion collisions provide an accurate mean to perform a tomographic measurement of the medium created in the collision through the study of the medium modified jet properties. The idea is…
PHENIX has measured direct photons in p+p and Au+Au collisions at sqrt{s_{NN}}=200 GeV. The p+p measurement is in good agreement with pQCD expectations. The nuclear modification factor in Au+Au is found to be consistent with unity for all…
We present results on two-particle correlations using singly-strange particles ($\Lambda$, $\bar{\Lambda}$, $K^0_S$) and charged hadrons at intermediate p_T in d+Au and Au+Au collisions at RHIC. We discuss properties of the near-side…
Charged-particle spectra associated with direct photon ($\gamma_{dir} $) and $\pi^0$ are measured in $p$+$p$ and Au+Au collisions at center-of-mass energy $\sqrt{s_{_{NN}}}=200$ GeV with the STAR detector at RHIC. A hower-shape analysis is…
We calculate the centrality dependence of direct photons produced in Au+Au collisions at sqrt{s}=200GeV and their transverse momentum spectra within the Parton-Hadron-String Dynamics (PHSD) transport approach. As sources for 'direct'…
A measurement of direct photons in p+p collisions at sqrt(s)=200 GeV is presented. A photon excess above background from pi^0 --> gamma+gamma, eta --> gamma+gamma, and other decays is observed in the transverse momentum range 5.5 < p_T < 7…
The measurements of direct photons in $1.0 < p_{T} < 5.0 $GeV/$c$ for p+p and Au+Au collisions have been made through the virtual photon method at PHENIX. The fraction of the virtual direct photon component to the inclusive $e^{+}e^{-}$…
Azimuthal correlations of direct photons at high transverse energy (8 $<$ E$_T$ $<$ 16 GeV) with away-side hadrons of transverse momentum (3 $<$ p$_T$ $<$ 6 GeV/c) have been measured over a broad range of centrality for $Au+Au$ collisions…
Comparing the measurements of the hadronic final state from partonic showers in proton-proton and heavy-ion collisions will reveal the modifications generated by the medium on partons produced in hard scatterings. This can be achieved by…
Azimuthal correlations of charged hadrons with direct-photon ($\gamma_{dir}$) and neutral-pion ($\pi^{0}$) trigger particles are analyzed in central Au+Au and minimum-bias $p+p$ collisions at $\sqrt{s_{_{NN}}} = 200$ GeV in the STAR…
A detailed study of various two-particle correlation functions involving photons and neutral pions is presented in proton-proton and lead-lead collisions at the LHC energy. The aim is to use these correlation functions to quantify the…
Recent results from the PHENIX experiment at RHIC are presented. In this second part of the overview we discuss new results on direct photon production at low p_T in Au+Au collisions and a systematic study of J/psi production in various…
The STAR Collaboration at RHIC reports measurements of azimuthal correlations of high transverse momentum (p_T) charged hadrons in Au+Au collisions at higher p_T than reported previously. As p_T is increased, a narrow, back-to-back peak…
Two-particle angular correlations have long been used as an observable for measuring the initial-state partonic transverse momentum $k_T$. Sensitivity to this small transverse momentum scale allows nonperturbative transverse momentum…
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…
Two types of penetrating probes, direct photon and QCD jets, are investigated in the background of a small and rapidly expanding droplet of quark-gluon plasma. The additional thermal electromagnetic radiation results in a $\sim$50\%…
Latest results from the PHENIX experiment at RHIC on these topics will be presented. Results will be shown for Au+Au compared to p-p collisions as well as compared to results from fully reconstructed jets at LHC.