We calculate the hadron spectra in high-energy pp, pA and AA collisions within a pQCD parton model. Analyses of experimental data show that the modification of the spectra in pA and AA as compared to that in pp collisions is consistent with multiple parton scattering scenario and is dictated by the transition from absorptive soft interaction at low pT to incoherent hard parton scattering at hig...

The multiscattering problem is studied in the matrix density formalism. We study how to isolate the quasi-classical degrees of freedom in order to connect them with a cascade approach. The different problems that arise, as well as their possible solutions, are discussed and exemplified with a pion-nucleus model. PACS. 03.65.Nk Scattering theory – 24.10.Lx Monte Carlo simulations (including hadr...

We explore a possibility to generate exotic hadrons dynamically in the scattering of hadrons. The s-wave scattering amplitude of an arbitrary hadron with the Nambu-Goldstone boson is constructed so as to satisfy the unitarity condition and the chiral low energy theorem. We find that the chiral interaction for the exotic channels is in most cases repulsive, and that the strength of the possible ...

The amplitudes of hadron-hadron forward elastic scattering at high energy are investigated on the basis of analiticity and crossing-symmetry which is valid in QCD. The universal uniformizing variable for them is proposed and the formulae for crossing-even and crossing-odd amplitudes are derived. The same parameters in these formulae determine the real and imaginary (total cross sections) parts ...

The extension of the factorization theorems of perturbative QCD to power corrections associated with re-scattering in nuclear collisions is reviewed. The importance of hadron-nucleus collisions is discussed. Perturbative QCD (pQCD) has been very successful in interpreting and predicting hadronic scattering processes in high energy collisions, even though the physics associated with individual h...

We study infrared contributions to semihard parton-parton interactions by considering an effective charge whose finite infrared behavior is constrained by a dynamical mass scale. Using an eikonal QCDbased model in order to connect this semihard parton-level dynamics to the hadron-hadron scattering, we obtain predictions for the proton-proton (pp) and antiproton-proton (p̄p) total cross sections,...

We propose generation of narrow-bandwidth GeV photons, gamma-rays, via Compton scattering of hard X-ray photons in X-ray free-electron laser oscillators [1]. The gamma-rays have a narrow-bandwidth spectrumwith a sharp peak, ∼0.1% (FWHM), due to the nature of Compton scattering in relativistic regime. Such gamma-rays will be a unique probe for studying hadron physics. In this paper, we discuss d...

Hard-scattering in p-p collisions was discovered in 1972 at the CERN-ISR, the first hadron collider. Techniques were developed and several hard-processes were discovered which form the basis for many of the measurements made in p-p and Au+Au collisions at RHIC. Recent measurements of hard-scattering and related reactions by the PHENIX experiment at RHIC are presented in this context.

We study the formation of resonances in terms of the chiral SU(3) Lagrangian. At leading order parameter-free predictions are obtained for the scattering of Goldstone bosons off any hadron once we insist on approximate crossing symmetry of the unitarized scattering amplitude. A wealth of empirically established resonances are recovered and so far unseen resonances are predicted. Here we review ...

We study the formation of resonances in terms of the chiral SU(3) La-grangian. At leading order parameter-free predictions are obtained for the scattering of Goldstone bosons off any hadron once we insist on approximate crossing symmetry of the unitarized scattering amplitude. A wealth of empirically established resonances are recovered and so far unseen resonances are predicted. Here we review...