Thermal Photon Production In The Qgp With Non-extensive Statistical Mechanics

In1970s, Lee and G.C.Wick and others predicated that in relativistic heavy-ion collisions quarks and gluons confined in nucleons may be deconfined to form a new kind of matter, quark-gluon plasma due to the high temperature and energy density created in the colliding center. With the continuous efforts of several generations of physicists, a kind of deconfined partonic matter may have been found. This extremely hot and dense QCD matter is most likely a strongly coupled quark-gluon plasma.Theoretical estimations shown that the QGP may live for a very short time about5～10fm. The direct photon enhancement is considered to be an ideal probe signal to study the QGP. Photons can leave the hot/dense QCD medium not being affected by the final state effect. By convoluting thermal photon rates with the space-time evolution and then confronted with experiment data we can get the information of the properties of the fireball. In this calculation, the equation of state is an important input of hydrodynamical model describing the dynamical evolution of the fireball.There is an important assumption in BG statistical mechanics:ergodicity, that is, within a certain period of time the system can traverse all microstates that may arise. However, according to recent studies, the hot and dense QCD matter may dissatisfy this assumption because of long range interactions and memory effects. Therefore applying Tsallis statistical mechanics to this hot and dense matter should give us new insight of the properties of the QGP.In this thesis, we calculate the thermal photon production using Tsallis statistical mechanics and find:(1)In both BG and Tsallis theory we observe that the rate rises with the increasing temperature.(2) The rate in non-extensive theory is lager than that in BG theory, and the deviation have a positive correlation with q.(3) When the energy or transverse momentum of photons rises, the deviation between two statistics becomes lager. In addition, we analysed the effect on the EOS and find that it will make a big difference even if q deviates1slightly.