Unraveling the myth of large pT hadron spectra in high-energy heavy-ion collisions

Hadron spectra in high-energy pp, pA and AA collisions are analyzed in a pQCD parton model, including initial k(T) and its broadening via initial multiple scattering. Within this model the hadron spectra in both pp and prl or Ail collisions carl be described very well for pr > 2 GeV/c. The modification of the spectra in pA and AA as compared to that in pp collisions is consistent with multiple parton scattering scenario. Such an analysis will shed new light on the physics one can extract from the single inclusive hadron spectra, e.g., freeze-out temperature and flow velocity in a thermal fire-ball model, and parton energy lass in dense matter.