Related papers: High-$p_{_{T}}$ Direct Photon Azimuthal Correlatio…
Azimuthal anisotropy ($v_2$) and two-particle angular correlations of high $p_T$ charged hadrons have been measured in Au+Au collisions at $\sqrt{s_{NN}}$=130 GeV for transverse momenta up to 6 GeV/c, where hard processes are expected to…
Dihadron azimuthal correlations containing a high transverse momentum ($p_T$) trigger particle are sensitive to the properties of the nuclear medium created at RHIC through the strong interactions occurring between the traversing parton and…
We present first results of azimuthal (Delta phi) correlations of high transverse momentum (p_T) hadrons from the high-statistics Au+Au dataset collected at RHIC in 2004. Previous correlations measurements observed the disappearance of…
Jet tomography, the study of differential energy loss of hard scattered partons to infer the density profile of the medium, is greatly improved by precise knowledge of the initial energy of the hard probe. As photons are not strongly…
We present the first measurement of directed flow ($v_1$) at RHIC. $v_1$ is found to be consistent with zero at pseudorapidities $\eta$ from -1.2 to 1.2, then rises to the level of a couple of percent over the range $2.4 < |\eta| < 4$. The…
We report a measurement of high-p_T inclusive pi^0, eta, and direct photon production in p+p and d+Au collisions at sqrt(s_NN) = 200 GeV at midrapidity (0 < eta < 1). Photons from the decay pi^0 -> gamma gamma were detected in the Barrel…
We report the measurement of first (\textit{n} = 1) and higher order(\textit{n} = 2-5) harmonic coefficients ($v_{n}$) of the azimuthal anisotropy in the distribution of the particles produced in Au+Au collisions at $\sqrt{s_{NN}}$ =200 GeV…
We present the preliminary measurement of azimuthal correlations between non-photonic electrons and charged hadrons in p+p collisions at $\sqrt{s_{NN}} = 200$ GeV from STAR. The results are compared to PYTHIA simulations to estimate the…
We have measured direct photons for $p_T<5~$GeV/$c$ in minimum bias and 0\%--40\% most central events at midrapidity for Cu$+$Cu collisions at $\sqrt{s_{_{NN}}}=200$ GeV. The $e^{+}e^{-}$ contribution from quasi-real direct virtual photons…
The measurement of the azimuthal-correlation function of prompt D mesons with charged particles in pp collisions at $\sqrt{s}$ = 5.02 TeV and p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV with the ALICE detector at the LHC is reported.…
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…
A method has been proposed for the determination of $\gamma$ to $\pi^0$ ratio in high energy pp and nucleus-nucleus collisions at large transverse momentum ($p_T$). In photon measuring device, it is proposed that shower shape analysis is…
Dilepton and direct photon measurements in heavy ion collisions provide access to the early stages of the collision. Dilepton continuum measurements at SPS and RHIC show an excess consistent with broadening of the rho meson spectral…
Direct photons are a powerful probe to study the properties of the unique matter created in ultrarelativistic heavy-ion collisions. They carry information on the various stages of a heavy-ion collision. At different transverse momenta (pT),…
The first measurements of the Fourier coefficients ($V_{n\Delta}$) of the azimuthal distributions of charged hadrons emitted from photon-proton ($\gamma$p) interactions at the LHC are presented. The data are extracted from 68.8 nb$^{-1}$ of…
We present measurements of azimuthal correlations of charged hadron pairs in $\sqrt{s_{_{NN}}}=200$ GeV Au$+$Au collisions for the trigger and associated particle transverse-momentum ranges of $1<p_T^t<10$~GeV/$c$ and…
The azimuthal anisotropy coefficients v_2 and v_4 of pi^0 and eta mesons are measured in Au+Au collisions at sqrt(s_NN)=200 GeV, as a function of transverse momentum p_T (1-14 GeV/c) and centrality. The extracted v_2 coefficients are found…
Measurements of inclusive and direct photon production at mid-rapidity in pp collisions at $\sqrt{s}=2.76$ and 8 TeV are presented by the ALICE experiment at the LHC. The results are reported in transverse momentum ranges of $0.4<p_{T}<10$…
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…
The measurement of the direct photon transverse momentum spectrum in Pb-Pb collisions at \unit[$\sqrt{s_{_{NN}}}=2.76]{TeV}$ with data taken by the ALICE experiment is presented. The measurement shows a clear direct-photon signal for 0-40%…