Related papers: Quarkonium Production at STAR
The three Upsilon states, Upsilon(1S+2S+3S), are measured in d+Au and p+p collisions at sqrt(s_NN)=200 GeV and rapidities 1.2<|y|<2.2 by the PHENIX experiment at the Relativistic Heavy-Ion Collider. Cross sections for the inclusive…
We present measurements of the differential cross sections of inclusive $J/\psi$ meson production as a function of transverse momentum ($p_{T}^{J/\psi}$) using the $\mu^{+}\mu^{-}$ and $e^{+}e^{-}$ decay channels in proton+proton collisions…
Strangeness enhancement has been predicted to be one of the signatures of the formation of the quark gluon plasma (QGP) and event-by-event fluctuations of strangeness may reveal the nature of such a phase transition. We report results for…
Charged hadrons (0.15 < pt < 4 GeV/c) associated with a large pt trigger particle (4 < pt < 6 GeV/c) are statistically reconstructed in the large acceptance STAR TPC for p+p and Au+Au collisions at sqrt(s_NN)=200 GeV. Preliminary results on…
We report first measurements of $e^{+}e^{-}$ pair production in the mass region 0.4 $<M_{ee}<$ 2.6 GeV/$c^{2}$ at low transverse momentum ($p_T<$ 0.15 GeV/$c$) in non-central Au$+$Au collisions at $\sqrt{s_{NN}}$ = 200 GeV and U$+$U…
Studying the production of J/$\psi$ (bound state of charm and anti-charm quark) in proton-proton collisions gives an opportunity to test quantum chromodynamics (QCD) calculations, as the production of J/$\psi$ involves both perturbative and…
The fraction of $J/\psi$ mesons which come from B-meson decay, $\textrm{F}_{B{\rightarrow}J/\psi}$, is measured for J/$\psi$ rapidity \mbox{$1.2<|y|<2.2$} and $p_T>0$ in $p$+$p$ and Cu+Au collisions at $\sqrt{s_{_{NN}}}$=200 GeV with the…
Data for Au+Au collisions at sqrt{s_{NN}}=200 GeV are analyzed to determine the ratios of identified hadrons ($\pi$, $K$, $p$, $\Lambda$) as functions of collision centrality and transverse momentum ($p_T$). We find that ratios of…
Based on a kinetic description of J/psi dissociation and production in an expanding quark-gluon plasma that is described by a 2+1 dimensional ideal hydrodynamics, we have studied the hot medium effects on J/psi production in p+Pb collisions…
We report that, unlike most inclusive quarkonium-production processes, the production rate for p p -> J/psi+Upsilon+X dominantly depends on two not well-known long-distance nonrelativistic QCD matrix elements, <O_8^{J/psi}(^3S_1)> and…
In these proceedings, an overview of recent quarkonium measurements in nuclear collisions carried out at both RHIC and LHC is presented. In p+p collisions, despite theoretical progresses made in understanding the production mechanisms for…
We present a summary of recent photoproduction results in ultra peripheral relativistic heavy ions collisions with STAR. These collisions have impact parameters larger then twice the nuclear radius; the nuclei do not physically collide, but…
Quark coalescence predictions for various multi-strange baryon to anti-baryon ratios for central Au+Au collisions at RHIC energies are compared to preliminary data of the STAR collaboration. The formation of Quark Matter and the sudden…
Theoretical models suggest that the Quantum Chromo-Dynamics (QCD) phase diagram has a critical point demarcating the order of transition between the two phases: the hadron gas, in which the quarks are confined and the Quark-Gluon Plasma…
At RHIC, enhancements in the baryon-to-meson ratio for light hadrons and hadrons containing strange quarks have been observed in central heavy-ion collisions compared to those in p+p and peripheral heavy-ion collisions in the intermediate…
We summarize here recent results from the STAR collaboration focusing on processes involving large momentum transfers. Measurements of angular correlations of di-hadrons are explored in both the pseudorapidity (eta) and azimuthal (phi)…
This contribution presents the latest results on heavy quarkonia (j/psi and upsilon) production in d+A and A+A collisions at RHIC at a center of mass energy per nucleon-nucleon collision sqrt(s_NN) = 200 GeV, measured by the PHENIX…
In this paper, J/$\psi$ polarization at mid-rapidity in $p+p$ collisions at $\sqrt{s}$ = 200 GeV measured in the STAR experiment at RHIC is reported. J/$\psi$ production is analyzed via the dielectron decay channel. J/$\psi$ polarization is…
Parton energy loss, quarkonium sequential melting and particle production from electromagnetic interactions are tools to study Quark Gluon Plasma properties. The STAR detector, with large acceptance at mid-rapidity, excellent particle…
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…