Signatures of the phase transition

by Boris Tomasik (Univerzita Mateja Bela), Roy Lacey (Stony Brook University)

Monday 24 Aug 2009, 11:00 → 12:00 Europe/Zurich

40-S2-D01 (CERN)

Presentation 1:Transport coefficients of the "perfect fluid" created in RHIC colisions There is now compelling evidence that the Quark Gluon Plasma (QGP) is produced in a rapid crossover phase transition in heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC). A primary focus of current RHIC efforts is centered on quantitative estimates of the transport coefficients of the QGP, as well as the question of whether or not it is strongly or weakly coupled. I will present new state-of-the-art scaling techniques which not only provide definitive constraints crucial for accurate estimates of the sound speed (c_s), mean free path (\lambda), viscosity (\eta/s), stopping power (q_{hat}), etc, but also show that the QGP created in RHIC collisions is strongly coupled. I will also discuss a few implications for the CERN heavy ion programs (both low and high energy). Presentation 2: Fireball fragmentation and the Kolmogorov-Smirnov test In the first half of this talk I shall argue that because of the rapid expansion in ultrarelativistic nuclear collisions the fireball could fragment into smaller pieces when passing the phase transition. In case of first-order phase transition this is the process known as spinodal decomposition which is widely known in general physics and even finds technological applications. At the crossover, fragmentation can occur owing to sudden appearance of large bulk viscosity. The second half of the talk will be devoted to a novel technique which can be used to identify the fragmentation. It is based on massive use of the Kolmogorov-Smirnov test and appears to be more sensitive than other conventional methods. EVO conferencing information: Title: Heavy Ion Forum Description:Heavy Ion Forum Community:ALICE - Meeting URL http://evo.caltech.edu/evoGate/koala.jnlp?meeting=MMMeMn2I2iDtDu929iD29M - Phone Bridge ID: 1183056

Slides Lacey_CERN_2009p.ppt