Related papers: PHENIX results on direct photon-hadron correlation…
The suppression of hadron p_T spectra in high energy central heavy-ion collisions compared to proton-proton collisions, referred to as 'jet-quenching', is currently attributed to partonic energy loss in the hot medium created in the…
We calculate in perturbative QCD the transverse momentum imbalance of dijet and dihadron production in high energy p+A (d+A) collisions. We evaluate the effect of both initial- and final-state multiple scattering, which determines the…
The versatility of RHIC allowed the PHENIX collaboration to measure low momentum direct photons from small systems, such as p+p, p+A, d+Au at $\sqrt{s_{NN}} = $200 GeV as well as from large A+A systems, such as Au+Au and Cu+Cu at 200 GeV…
Dihadron azimuthal correlations containing a high transverse momentum ($p_T$) trigger particle are sensitive to the properties of the nuclear medium created at RHIC through the strong interactions occurring between the traversing parton and…
Charm and bottom quarks are formed predominantly by gluon fusion in the initial hard scatterings at RHIC, making them good probes of the full medium evolution. Previous measurements at RHIC have shown large suppression and azimuthal…
The observation of jet quenching in ultra-relativistic heavy ion collisions demonstrates significant energy loss of fast partons when passing through the created medium. Correlations between final-state particles at intermediate transverse…
The PHENIX experiment at RHIC has measured the centrality dependence of the direct photon yield from Au$+$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…
Hard probes created through large momentum transfers are used to study the properties of QCD matter created in heavy-ion collisions, by comparing the measurements to those in p+p collisions. Jets, and the "quenching" or suppression of jets…
The PHENIX experiment at the Relativistic Heavy Ion Collider has measured 2nd and 3rd order Fourier coefficients of the azimuthal distributions of direct photons emitted at midrapidity in Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV for…
Measurements at RHIC and the LHC show strongly enhanced baryon-to-meson yield ratios at intermediate transverse momenta ($p_{\rm{T}}$) in high-energy nuclear collisions compared to $p$+$p$ baseline. This enhancement is attributed to the…
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…
In 1998, at the 4th QCD workshop, Rolf Baier asked me whether jets could be measured in Au+Au collisions because he had a prediction of a QCD medium-effect (energy loss via soft gluon radiation induced by multiple scattering) on…
When studying the initial state and evolution of the matter created in relativistic heavy ion collisions, high-pT direct photons are a powerful probe. They are created in initial hard processes and in parton fragmentation, and possibly in…
One unexpected recent result from heavy-ion collisions is the large suppression and elliptic flow of electrons from heavy flavor decay. Further measurements of properties of electrons from heavy flavor decay are crucial to understanding the…
The PHENIX experiment at the Relativistic Heavy Ion Collider measured the second Fourier component $v_2$ of the direct-photon azimuthal anisotropy at midrapidity in Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV. The results are presented…
High transverse momentum (P_T) processes are considered to be an important tool to probe and understand the medium produced in ultrarelativistic heavy-ion collisions via the interaction of hard, perturbatively produced partons with the…
Recently we have conjectured that (in-)elastic collisions of (pre-)hadronic high momentum states with the bulk of hadrons in the late fireball might substantially account for the attenuation of the high transverse momentum hadrons at RHIC.…
Recent results on direct photons and dileptons from the PHENIX experiment opened up a possibility of landscaping electro-magnetic radiation over various kinetic energies in heavy ion collisions. Results on direct photon measurement in Au+Au…
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…
Based on a multi-phase transport model, the measured jet fragmentation function ratio of Pb+Pb collisions to p+p collisions in CERN Large Hadron Collider experiments is decomposed into two parts, corresponding to the two contributions of…