No Arabic abstract
Quarkonia suppression in nucleus-nucleus collisions is a powerful tool to probe the density and temperature of the medium created in heavy ion collisions. Forward rapidity measurements in $p(d)$+Au collisions are essential to understand how quarkonia states are affected by initial state effects, formation time, and local particle multiplicity. Earlier measurements in Au+Au collisions showed a stronger suppression of forward $J/psi$ compared to mid-rapidity results, indicating the possibility of a smaller contribution of regenerated quarkonia states at forward rapidity. These proceedings report on the latest quarkonia studies performed by the PHENIX collaboration in the rapidity range $1.2<|y|<2.2$.
The production of the low-mass dielectrons is considered to be a powerful tool to study the properties of the hot and dense matter created in the ultra-relativistic heavy-ion collisions. We present the preliminary results on the first measurements of the low-mass dielectron continuum in Au+Au collisions and the phi meson production measured in Au+Au and d+Au collisions at sqrt{s_NN} = 200 GeV performed by the PHENIX experiment.
Recent results on identified hadrons from the PHENIX experiment in Au+Au collisions at mid-rapidity at $sqrt{s_{NN}}$ = 200 GeV are presented. The centrality dependence of transverse momentum distributions and particle ratios for identified charged hadrons are studied. The transverse flow velocity and freeze-out temperature are extracted from $p_{T}$ spectra within the framework of a hydrodynamic collective flow model. Two-particle HBT correlations for charged pions are measured in different centrality selections for a broad range of transverse momentum of the pair. Results on elliptic flow measurements with respect to the reaction plane for identified particles are also presented.
Recent results on identified hadrons from the PHENIX experiment in Au+Au collisions at mid-rapidity at $sqrt{s_{NN}}$ = 200 GeV are presented. The centrality dependence of transverse momentum distributions and particle ratios for identified charged hadrons are studied.
The latest PHENIX results for particle production are presented in this paper. A suppression of the yield of high p_t (transverse momentum) hadrons in central Au+Au collisions is found. In contrast, direct photons are not suppressed in central Au+Au collisions and no suppression of high p_t particles can be seen in d+Au collisions. This leads to the conclusion that the dense medium formed in central Au+Au collisions is responsible for the suppression. It is as well found, that the properties of this medium are similar to the one of a liquid. Further measurements provide information about the chiral dynamics of the system.
A novel Hadron Blind Detector (HBD) has been developed for an upgrade of the PHENIX experiment at RHIC. The HBD will allow a precise measurement of electron-positron pairs from the decay of the light vector mesons and the low-mass pair continuum in heavy-ion collisions. The detector consists of a 50 cm long radiator filled with pure CF4 and directly coupled in a windowless configuration to a triple Gas Electron Multiplier (GEM) detector with a CsI photocathode evaporated on the top face of the first GEM foil.