Related papers: (Multiple) Hard Parton Interactions in Heavy-Ion C…
At ultra-relativistic energies the minijet production in heavy-ion collisions becomes sensitive to semi-hard parton rescatterings in the initial stages of the process. As a result global characteristics of the event, like the initial…
Measurements of various particle species over an extended momentum range provide a sensitive experimental tool for investigating particle production mechanisms in hadronic collisions. Comparison of the spectral shapes from different…
Hadron multiplicity in the central rapidity region of high-energy heavy-ion collisions is investigated within a two-component mini-jet model which consists of soft and semi-hard particle production. The hard contribution from mini-jets is…
A short historical review is made of charged particle production at high energy proton synchrotrons and at pp and {p}p colliders. The review concerns mainly low p_t processes, including diffraction processes, and fragmentation of nuclei in…
In a suitably chosen back-to-back kinematics, four-jet production in hadronic collisions is known to be dominated by contributions from two independent partonic scattering processes, thus giving experimental access to the structure of…
In the past decade the observation of cross section modification for leading hadrons, heavy flavor and two particle correlations in heavy ion collisions has provided important insights into the dynamics of parton propagation in dense…
We compute the centrality dependence of multiplicities of particles produced in ultrarelativistic nuclear collisions at various energies and atomic numbers. The computation is carried out in perturbative QCD with saturated densities of…
We argue that high energy proton-nucleus (p+A) collisions provide an excellent laboratory for studying nuclear size enhanced parton multiple scattering where power corrections to the leading twist perturbative QCD factorization approach can…
Highlights of recent results from the STAR collaboration focusing on hard probes of the initial and final state are presented. New results at forward rapidities in d+Au collisions at low $x$ are utilized to study the possible onset of…
Hard probes - final state particles related to an interaction with large momentum transfer or mass scale - play a distinguished role in the discovery and the study of the Quark-Gluon Plasma (QGP), a phase of deconfined quarks and gluons…
We discuss several examples of how the transverse spatial distribution of partons in the nucleon, as well as multiparton correlations, can be probed by observing hard processes (dijets) in high-energy pp (pbar p) and pA (dA) collisions.…
We present a systematic calculation of the coherent multiple parton scattering with several nucleons in lepton-nucleus and hadron-nucleus collisions. We show that in l+A reactions coherence leads to nuclear shadowing in the structure…
It is becoming increasingly clear that initial state effects inherent to collisions of nuclei play an important role in the interpretation of data from heavy ion collisions at RHIC and the LHC. Such effects are more apparent in kinematic…
Large enhancement of (anti)protons relative to pions has been observed at intermediate pT $\sim$ 2-5 GeV/c in central Au+Au collisions at RHIC. To investigate the possible source of this baryon enhancement, we performed a systematic study…
We describe particle production in the framework of an independent string model: the dual parton model. We show that an improved version of this model, containing a diquark breaking component, allows to describe the bulk of particle…
Reconstructed jets in heavy ion collisions are a crucial tool for understanding the quark-gluon plasma. The separation of jets from the underlying event is necessary particularly in central heavy ion reactions in order to quantify medium…
Photoproduction in ultra-peripheral relativistic heavy-ion collisions displays many unique features, often involving quantum mechanical coherence and two-source interference between photon emission from the two ions. We review the recent…
The experimental data for identified hadron spectra from pp,d+A and AA collisions are reviewed. Three regions with different dominant production mechanisms are considered: soft region (pt <2 GeV/c) - with large degree of collectivity and…
We report results of our ongoing nonperturbative numerical study of a classical effective theory describing low-x partons in the central region of a heavy-ion collision. In particular, we give estimates of the initial transverse energies…
Correlation between shower partons is first studied in high $p_T$ jets. Then in the framework of parton recombination the correlation between pions in heavy-ion collisions is investigated. Since thermal partons play very different roles in…