Quark Matter 2008 Highlights

The 20th International Conference on Ultra-Relativistic Nucleus Nucleus Collisions, Quark Matter 2008, took place February 4-10 in Jaipur, India. The Quark Matter conference is the biggest and most important conference in the field of Relativistic Heavy-Ion Collisions and traditionally the experimental collaborations reserve it as the forum to present their latest and most important results. (more…)

Scaling and Non-Scaling of Elliptic Flow

The detailed dependence of the elliptic flow parameter v2 on the particle masses and transverse momentum has provided strong evidence for the applicability of hydrodynamics for describing the bulk motion of final-state particles at RHIC. (For a partial list of references, see the Hydro Primer elsewhere in this journal.) Equally intriguing have been various scaling patterns observed in the flow data: The separate curves v2(pT,m) for different mass particles are substantially more alike when studied versus “transvese kinetic energy” KET = mT -m. Plotting v2 as as a function of KET collapses the data into one curve for KET < 1 GeV, while showing two distinct branches for mesons and baryons for larger values of KET. These two branches collapse into one curve when both v2 and KET are divided by the quark content nq (2 for mesons, 3 for baryons). (more…)