D. Yu. Peressounko

Photon emission in Pb + Pb collisions at SpS and LHC

Abstract The yield of direct photons in Pb + Pb collisions at SpS and LHC energies is evaluated with emphasis on estimates of possible uncertainties. The possibility of experimental observation of direct photons at LHC is discussed. Predictions of several models at SpS energy are compared.

Direct hadron production in ultrarelativistic heavy-ion collisions

Hadrons emitted by the pre-surface layer of quark-gluon plasma (QGP) before phase transition into hadronic gas are considered as possible source of direct information about QGP. It is shown that these hadrons dominate at soft p_t if QGP is created in ultrarelativistic heavy ion collisions.Abstract Hadrons emitted by the pre-surface layer of a quark-gluon plasma (QGP) before the phase transition into a hadronic gas are considered as possible sources of direct information about QGP. It is shown that if QGP is created in ultrarelativistic heavy-ion collisions, then these hadrons strongly contribute at soft p t at SpS energy and dominate up to an order of magnitude at LHC energy.