Speaker
Dr
Harri Niemi
(University of Jyväskylä, Department of Physics)
Description
Nowadays, relativistic dissipative fluid dynamics is a common tool to
describe the space-time evolution of the quark-gluon plasma (QGP)
created in ultrarelativistic heavy-ion collisions. The validity of the fluid-dynamical approach is experimentally confirmed by the fact that
initial-state anisotropies are directly converted into nonvanishing
(event-averaged) Fourier coefficients $\langle v_n \rangle$ of the
decomposition of the single-inclusive momentum distribution of hadrons
with respect to the azimuthal angle. From the magnitude of the $\langle v_n \rangle$ one can obtain information about the size of dissipative corrections and thus infer the value of the viscous coefficients of the QGP.
It has been realized that, for a proper comparison to experimental data
and a reliable extraction of viscosity, fluid-dynamical calculations have to be performed on an event-by-event basis. Therefore, fluid dynamics should not only be able to predict the correct event-averaged $\langle v_n\rangle$, but also their distributions. In this paper, we investigate the event-by-event distribution of the initial-state eccentricities $\varepsilon_n$, and show how they correlate with the event-by-event distribution of the Fourier coefficients $v_n$. In order to generate the initial state, we use the Monte-Carlo Glauber model of Ref.\ [1]. For the fluid-dynamical evolution, we use the model of Refs.\ [2]. The final hadron spectra are calculated with the Cooper-Frye freeze-out procedure.
We demonstrate that the event-by-event distributions of the $v_n$,
and not only their average values, are promising observables to
gain information about the initial state of the fluid-dynamical evolution and the transport properties of the hot and dense, strongly interacting matter created in heavy-ion collisions.
[1] H.~Holopainen, H.~Niemi, and K.~J.~Eskola,
Phys.\ Rev.\ {\bf C83}, 034901 (2011),
[arXiv:1007.0368 [hep-ph]].
[2] H.~Niemi, G.~S.~Denicol, P.~Huovinen, E.~Molnar, and D.~H.~Rischke,
Phys.\ Rev.\ Lett.\ {\bf 106}, 212302 (2011),
[arXiv:1101.2442 [nucl-th]];
H.~Niemi, G.~S.~Denicol, P.~Huovinen, E.~Molnar and D.~H.~Rischke,
arXiv:1203.2452 [nucl-th].
Primary author
Dr
Harri Niemi
(University of Jyväskylä, Department of Physics)
Co-authors
Dirk Rischke
(University Frankfurt)
Dr
Etele Molnar
(MTA Wigner Research Centre for Physics)
Gabriel Denicol
(Frankfurt University)
Hannu Holopainen
(Frankfurt Institute for Advanced Studies)
Pasi Huovinen
(Johann Wolfgang Goethe-Universität)
