6533b832fe1ef96bd129af68
RESEARCH PRODUCT
Photon emission in heavy ion collisions at the CERN SPS
Sami Sakari RasanenP.v. RuuskanenP. HuovinenP. Huovinensubject
PhysicsNuclear and High Energy PhysicsPhotonLarge Hadron ColliderNuclear TheoryHadronFOS: Physical sciencesSpectral lineNuclear Theory (nucl-th)Nuclear physicsTransverse planeHigh Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)ThermalHeavy ionNuclear ExperimentEnergy (signal processing)description
We compute the thermal photon spectrum in the Pb+Pb collisions at the CERN SPS energy using thermal emission rates and a hydrodynamic description for the evolution of produced hot matter and compare our results with the measurements of the excess photons by the WA98 collaboration. Our results show that the measured photon spectrum can be reproduced with realistic initial conditions which take properly into account also the finite longitudinal size of the initial collision zone and which simultaneously describe well both the transverse and longitudinal hadron spectra. In the scenario with initial formation of QGP the recently calculated emission rate, complete to order alpha_s, reproduces the measured spectrum. However, the experimental spectrum can also be reproduced in a purely hadronic scenario without transition to QGP state, but a high initial temperature, much over the values predicted for the phase transition temperature T_c, is required.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2001-11-16 |