Speaker
Prof.
Francesco Becattini
(University of Florence (Italy))
Description
We present a quantitative study of vorticity formation in peripheral ultrarelativistic
heavy ion collisions at $\sqrt{s_{NN}} = 200$ GeV by using the ECHO-QGP numerical code,
implementing relativistic dissipative hydrodynamics in the causal Israel-Stewart
framework in 3+1 dimensions with an initial Bjorken flow profile. We consider and
discuss different definitions of vorticity which are relevant in relativistic
hydrodynamics. After demonstrating the excellent capabilities of our code, which
proves to be able to reproduce Gubser flow up to 8 fm/$c$, we show that, with the
initial conditions needed to reproduce the measured directed flow in peripheral
collisions corresponding to an average impact parameter $b=11.6$ fm
and with the Bjorken flow profile for a viscous Quark Gluon Plasma with $\eta/s=0.1$
fixed, a vorticity of the order of some $10^{-2} \; c$/fm can develop at freezeout.
The ensuing polarization of $\Lambda$ baryons does not exceed 1.4\% at midrapidity.
We show that the amount of developed directed flow is sensitive to both the initial
angular momentum of the plasma and its viscosity.
Author
Prof.
Francesco Becattini
(University of Florence (Italy))
Co-authors
Dr
Andrea Beraudo
(INFN Torino (Italy))
Mr
Gabriele Inghirami
(FIAS Frankfurt (Germany))
Dr
Luca Del Zanna
(Unviersity of Florence (Italy))
Dr
Valentina Rolando
(University of Ferrara (Italy))
