Speaker
LaszloPal Csernai
(UiB)
Description
Fluid dynamical processes became a dominant direction of research in high energy heavy ion reactions. The QuarkGluon plasma formed in these reactions has low viscosity [1], which leads to significant fluctuations and turbulent instabilities [2]. One has to study and separate these two effects [3], but this is not done yet in experiments. When such separation is performed, both fluctuations and new collective effects, like rotation and turbulence and the arising polarization [4] and two particle correlations [5] can be studied. The polarization arises from the shear flow based on the equipartition principle between local flow vorticity [6] and particle spin. Vorticity increases with beam energy in peripheral collisions, while higher temperatures counteract spin alignment. Due to these two effects polarization is expected to be observable at lower energies also [6].
http://folk.uib.no/csernai_lp/Thermal-8.pdf
FIG. 1. (Color online) The relativistic weighted thermal vorticity calculated in the reaction [x-z]
plane at t=3.72 fm/c. The energy of the U+U collision is $\sqrt{s_{NN}}$ = 4.0 + 4.0 GeV, b = 0.5bmax, and the cell size is dx = dy = dz = 0.61 fm. The average, energy weighted vorticity, is 0.0856 / 0.0658 for the two selected times. From ref. [6].
[1] L.P. Csernai, J.I. Kapusta and L.D. McLerran, Phys. Rev. Lett. **97**, 152303 (2006)
[2] L.P. Csernai, V.K. Magas, H. Stoecker and D.D. Strottman Phys. Rev. C **84**, 024914 (2011);
L.P. Csernai, D.D. Strottman and Cs. Anderlik, Phys. Rev. C **85**, 054901 (2012)
[3] L.P. Csernai and H. Stoecker, J. Phys. G **41**, 124001 (2014)
[4] F. Becattini, L.P. Csernai and D.J. Wang, Phys. Rev. C **88**, 034905 (2013)
[5] L.P. Csernai, S. Velle, and D.J. Wang, Phys. Rev. C **89**, 034916 (2014)
[6] L.P. Csernai, D.J. Wang, M. Bleicher, and H. Stoecker, Phys. Rev. C **90**, 021904R (2014)
Author
LaszloPal Csernai
(UiB)
Co-author
Horst Stoecker
(GSI)
