Related papers: Higher order QED in high mass e+ e- pairs producti…
In this thesis we describe the calculation of the process e+ e- --> Z/gamma -> Q Qbar + X, where Q is a heavy quark, X is anything else at order alpha_s^2.
The PHENIX experiment has established jet quenching at a center-of-mass energy of 200 GeV in Au+Au collisions. Recent measurements of Cu+Cu collisions at the same center-of-mass energy support a parton energy loss scenario. Furthermore, the…
The PHENIX experiment at RHIC has measured $\omega$ and $\phi$ mesons in $p+p$, $d+Au$ and $Au+Au$ collisions at \sqn = 200 GeV via both hadronic and di-electron decay channels. The transverse momentum spectra as measured in different decay…
We study the pair production of scalar top quarks in e+e- collisions with the subsequent decay of the top squarks into b-quarks and charginos. We simulate this process using PYTHIA6.4 for beam energies 2E_beam = 350, 400, 500, 800, 1000…
Great interest has attached to recent Au+Au, E = 200 A GeV measurements at RHIC, obtained with the PHENIX, STAR, PHOBOS and BRAHMS detectors. For central collisions and vanishing pseudo-rapidity all experiments indicate a considerable…
We present a calculation of the full next-to-leading order QCD corrections to the scattering process pp \to t tbar Z. This channel will be used to measure the t tbar Z electroweak couplings at the Large Hadron Collider. These couplings…
Results of analytical calculations for heavy quark systems in higher orders of perturbation theory are overviewed. I discuss baryons with one finite mass quark in the next-to-leading order and heavy quark pair production near the threshold…
The PHENIX experiment at RHIC has a unique large rapidity coverage ($1.2 < |y| < 2.2$) for heavy flavor studies in heavy-ion collisions. This kinematic region has a smaller particle density and may undergo different nuclear effects before…
In a leading order pQCD model, we have studied the heavy flavor production in p+p collisions at RHIC and LHC energy. Leading order pQCD models require a K-factor. At RHIC energy, $\sqrt{s}$=200 GeV, we fix K such that the model reproduces…
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…
The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory delivers the world's highest energy polarized proton-proton collisions at a center of mass energy up to 500 GeV and provides a unique opportunity to study the…
We present measurements of $e^+e^-$ production at midrapidity in Au$+$Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV. The invariant yield is studied within the PHENIX detector acceptance over a wide range of mass ($m_{ee} <$ 5 GeV/$c^2$) and…
The complete one-loop QED initial state, final state and initial--final state interference corrections to the process e+e- -> pi+pi- are presented. Analytic formulae are given for the virtual and for the real photon corrections. The total…
It is shown that a QCD based nuclear absorption model, with few parameters fixed to reproduce experimental $J/\psi$ yield in 200 GeV pp/pA and 450 GeV pA collisions can explain the preliminary PHENIX data on the centrality dependence of…
Measurement of the in-medium energy loss of fast partons is one of the most active topics in heavy-ion physics. Such studies provide an opportunity to gain insight into the fundamental behavior of QCD processes by studying them away from…
sPHENIX is a next-generation experiment at RHIC for jet and heavy-flavor physics which was fully commissioned during 2023 and 2024. Using its novel streaming-readout-capable, precision tracking system, sPHENIX collected 100 billion unbiased…
PHENIX results for $J/\psi$ production in $p+p$, $d+Au$, and $Cu+Cu$ collisions at $\sqrt{s_{NN}}=200$ GeV are presented.
Heavy quarkonia production is expected to be sensitive to the formation of a quark gluon plasma (QGP). The PHENIX experiment has measured $J/\psi$ production at $\sqrt{s_{NN}}=$~200 GeV in Au+Au and Cu+Cu collisions, as well as in reference…
We review recent results from the RHIC beam energy scan (BES) program, aimed to study the Quantum Chromodynamics (QCD) phase diagram. The main goals are to search for the possible phase boundary, softening of equation of state or first…
The total and differential cross sections of the process e+e- -> n gamma with n >= 2 are measured using data collected by the L3 experiment at centre-of-mass energies of \sqrt{s}=183 and 189 GeV. The results are in agreement with the…