Speaker
Edward Shuryak
(stony brook university)
Description
High Multiplicity pp and pA Collisions are a place where the macroscopic description (thermodynamics and hydrodynamics) meets with the microscopic one (pomerons and QCD strings). First I discuss what happens with the hydrodynamical predictions as the system size gets smaller and smaller. For simplicity, we don't do it numerically, but analytically using Gubser$^\prime$ s flow. We found that the radial flow is expected to increase, while the elliptic flow decreases, and higher harmonics stronger suppressed. Then we approach the problem from the opposite side, using a string-based Pomeron model. We found that as the intrinsic temperature of the string grows, it approaches the Hagedorn regime and produces a high entropy string ball, amusingly dual to a certain black hole. Furthermore, when the string temperature narrows on the Hagedorn temperature or $T/T_H-1={\cal O}(1/N_c)$, the stringy ball becomes a sQGP ball with non-negligible pressure and hydrodynamical flow.
