Two-particle correlations obtained from parton showers that pass the hot and dense medium of the quark gluon plasma (QGP) can be used as an alternative observable, in addition to the combination of the nuclear modification factor RAA and the elliptic flow v2, to study the mechanisms of in-medium heavy quark energy-loss. In particular, angular correlations represent a promising tool to distingui...

Dynamical screening in the magnetic part of the one-gluon exchange interaction is included in the study of radiative energy loss of a fast parton propagating inside a quark-gluon plasma. As a result the final radiative energy loss is about twice as large as when only the electric part of one-gluon exchange interaction is considered. A non-perturbative magnetic screening mass is also used in the...

In the theory of deep inelastic scattering (DIS) the final state interaction (FSI) between the struck quark and the remnants of the target is usually assumed to be negligible in the Bjorken limit. This assumption, still awaiting a full validation within nonperturbative QCD, is investigated in a model composed by two relativistic particles, interacting via a relativistic harmonic oscillator pote...

CONTENTS 1) Introduction 1.1) Notation 2) Polarized lepton-nucleon deep inelastic scattering – general aspects 2.1) General formalism in the one photon exchange approximation 2.1.1) Structure functions and Bjorken scaling 2.1.2) Cross-section differences 2.1.3) Experimental measurement of g 1 and g 2 on nucleon targets a) Longitudinally polarized target b) Transversely polarized target c) Combi...

Hadron production in single and central diffraction dissociation is studied in a model which includes soft hadron interaction as controlled by a supercritical pomeron parametrization and hard diffraction. Hard diffraction is described using leading-order QCD matrix elements together with the parton distributions for the proton, the less well known photon parton densities and a conjectured parto...

We try to understand recent data on proton-proton and deuteron-gold collisions at RHIC, employing a modified parton model approach. 1 Interesting data from RHIC The nuclear modification factor R = (dNAA/d pt) / (Ncoll dNpp/d pt) shows interesting features: For AuAu, it is much smaller than one for central collisions, whereas for d-Au, it is bigger than one for central collisions. With decreasin...

Differential elliptic flow out to p⊥ ∼ 5 GeV/c is calculated using the MPC elastic parton cascade model for Au+Au at Ecm ∼ 130 A GeV. The results are compared to recent STAR/RHIC elliptic flow data. An elliptic flow pattern comparable to the data seems to require initial parton densities at least twice higher than the predicted by the HIJING model. Elliptic flow is also shown to be sensitive to...

Leading charm hadrons produced in hadron-nucleus interactions cannot be adequately described within the parton fusion model. Recent results on charm baryon production in Σ − A interactions at 330 GeV with the WA89 detector disagree with fusion predictions. Intrinsic heavy quark pairs in the Σ − (dds) wavefunction provide a simple mechanism for producing fast charm hadrons. We calculate leading ...