Related papers: Jet properties from direct $\gamma$ - hadron corre…
Direct photons were measured with the PHENIX experiment in p+p, d+Au, and Au+Au at sqrt(s_NN) = 200 GeV. To tackle the p_T region below 5 GeV/c, direct photons were measured through their internal conversion into e^+e^- in Au+Au collisions.
The physics of hadron-hadron collisions is very complex involving both perturbative and non-perturbative QCD. It is therefore imperative to study p-p collisions in as much detail as possible to provide a wide variety of data against which…
The PHENIX experiment discovered a large excess of low-$p_{T}$ direct photons in Au+Au collisions at 200 GeV compared to reference p+p collisions, which has been attributed to thermal radiation from the medium produced in the collisions. At…
We report on the observation of jet-like azimuthal and pseudorapidity correlations between the highest $p_T$ photon (leading photon) and charged hadrons produced in both p+p and Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV.
PHENIX has measured the two particle azimuth correlation in Au + Au at $\sqrt{s}$ = 200 GeV. Jet shape and yield at the away side are found to be strongly modified at intermediate and low $p_T$. The modifications vary dramatically with…
We report new results of $\gamma_{dir}$+hadron and $\pi^{0}$+hadron azimuthal correlations as a measure of the away-side jet-like correlated yields in central Au+Au and p+p collisions at $\sqrt{s_{NN}}$ = 200 GeV in the STAR experiment from…
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 latest two- and three-particle correlation measurements obtained by the PHENIX collaboration are presented. Three-particle correlations are consistent with the presence of conical emission patterns in the data. Two-particle correlations…
The PHENIX experiment at RHIC has been carried out to investigate the properties of QGP. Di-electron yields in p+p and Au+Au collisions have been measured. An enhancement of the yield over a hadronic cocktail calculation is clearly seen for…
Hadron correlations in jets, ridges and opposite dijets at all $p_T$ above 2 GeV/c are discussed. Since abundant data are available from RHIC at intermediate $p_T$, a reliable hadronization scheme at that $p_T$ range is necessary in order…
PHENIX has used the versatility of RHIC to map out low $p_{T}$ direct photon production as function of collision system size and beam energy. For systems with a size corresponding to a $dN_{ch}/d\eta$ larger than 20-30, we observe a large…
Recent results at STAR for direct $\gamma$-charged hadron azimuthal correlations in heavy-ion collisions are presented. These correlations are used to study the color charge density of the medium through the medium-induced modification of…
The recent results at RHIC for direct $\gamma$-charged hadron azimuthal correlations in heavy-ion collisions are presented. We use these correlations to study the color charge density of the medium through the medium-induced modification of…
We present a calculation of direct photon production at next-to-leading order of QCD and a matching of this calculation with parton showers using POWHEG BOX. Based on simulations with POWHEG+PYTHIA, we perform a detailed phenomenological…
The PHENIX experiment at RHIC has measured the centrality dependence of the direct photon yield from Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV down to $p_T=0.4$ GeV/$c$. Photons are detected via photon conversions to $e^+e^-$ pairs…
Direct photon spectra measured at small $p_T$ in p+p, d+Au and Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV are presented. Several measurement techniques including statistical subtraction, tagging, and internal and external conversion were…
The measurement of azimuthal correlations between two particles is a powerful tool to investigate the properties of strongly-interacting nuclear matter created in ultra-relativistic heavy-ion collisions. We present measurements of di-hadron…
Two particle azimuthal correlation functions are presented for charged hadrons produced in Au-Au collisions at RHIC sqrt(s_NN)=200 GeV.The correlation functions indicate sizeable asymmetries and anisotropies. The trend of the asymmetries is…
We measure the relative abundances of strange mesons, baryons, and anti-baryons correlated with high-$p_T$ trigger particles in $^{197}$Au + $^{197}$Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. Particle yields and ratios are extracted on the…
Transverse momentum distributions and yields for $\pi^{\pm}$, $K^{\pm}$, $p$ and $\bar{p}$ in $p+p$ collisions at $\sqrt{s}$=200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the Relativistic Heavy Ion Collider…