Pion production in d+Au collisions at RHIC energy

We present our results on neutral pion pi0 production in pp and dAu collisions at RHIC energy. Pion spectra are calculated in a next-to-leading order (NLO) perturbative QCD-based model. The model includes the transverse component of the initial parton distribution (``intrinsic kT''). We compare our results to the available experimental data from RHIC, and fit the data with high precision. The calculation tuned this way is repeated for the dAu collision, and used to investigate the interplay of shadowing and multiple scattering at RHIC. The centrality dependence of the nuclear modification factor shows a measurable difference between different shadowing parameterizations.Comment: Final version published in the Eur. Phys. J. ST in the Proceedings of the Zimanyi Memorial Workshop, 2-4 July, 2007, Budapest, Hungary; 12 pages in Latex, 6 EPS figure

K+/pi+ probes of jet quenching in AA collisions

Non-abelian energy loss in quark gluon plasma is shown to lead to novel hadron ratio suppression patterns in ultrarelativistic nuclear collisions. We apply recent (GLV) estimates for the gluon radiative energy loss, which increases linearly with the jet energy up to E<20 GeV and depends quadratically on the nuclear radius, R. The K+/\pi+ ratio is found to be most sensitive to the initial density of the plasma.Comment: Presented at 6th International Conference on Strange Quarks in Matter: 2001: A Flavourspace Odyssey (SQM2001), Frankfurt, Germany, 25-29 Sep 200

Kaon and Pion Ratio Probes of Jet Quenching in Nuclear Collisions

Non-abelian energy loss in quark gluon plasmas is shown to lead to novel hadron ratio suppression patterns in ultrarelativistic nuclear collisions. We apply GLV estimates for the gluon radiative energy loss. The K^-/K^+ and K^+/\pi^+ ratios are found to be most sensitive to the initial density of the plasma.Comment: 10 pages in Latex, 6 EPS figure

Jet Tomography Studies in AuAu Collision at RHIC Energies

Recent RHIC results on pion production in AuAu collision at sqrt(s)=130 and 200 AGeV display a strong suppression effect at high p_T. This suppression can be connected to final state effects, namely jet energy loss induced by the produced dense colored matter. Applying our pQCD-based parton model we perform a quantitative analysis of the measured suppression pattern and determine the opacity of the produced deconfined matter.Comment: Talk given at European Physical Society International Europhysics Conference on High Energy Physics HEP2003, July 17-23. 2003, in Aachen, Germany 3 pages in LaTeX, 2 EPS figure. (Accepted for publication in European Physical Journal C direct

High-p_T Pion Production in Heavy-Ion Collisions at RHIC energies

Perturbative QCD results on pion production are presented in proton-proton, proton-nucleus and nucleus-nucleus collisions from CERN SPS up to RHIC energy. A K_{jet}(s, p_T, Q) factor obtained from jet production is applied to perform next-to-leading order calculations. Using the intrinsic transverse momentum (k_T) we determined transverse momentum spectra for pions in wide energy region. We have investigated nuclear multiscattering and the Cronin effect at RHIC energies.Comment: Talk given at XXXII. International Symposion on Multiparticle Dynamics (ISMD'02) Alusha, Crimea, Ukraine, 7-13 September 2002. 4 pages in Latex, 1 PS figur