Directed Flow of Charged Particles at Midrapidity Relative to the Spectator Plane in Pb-Pb Collisions at root s(NN)=2.76TeV

0425246 - ÚJF 2014 RIV US eng J - Článek v odborném periodiku
Abelev, B. - Adam, J. - Adamová, Dagmar - Bielčík, J. - Bielčíková, Jana - Čepila, J. - Křelina, M. - Křížek, Filip - Krus, M. - Kučera, Vít - Kushpil, Svetlana - Kushpil, Vasilij - Mareš, Jiří A. - Pachr, M. - Petráček, V. - Petráň, M. - Polák, Karel - Pospíšil, V. - Schulc, M. - Šmakal, R. - Špaček, M. - Šumbera, Michal - Tlustý, D. - Vajzer, Michal - Wagner, V. - Zach, Č. - Závada, Petr … celkem 990 autorů
Directed Flow of Charged Particles at Midrapidity Relative to the Spectator Plane in Pb-Pb Collisions at root s(NN)=2.76TeV.
Physical Review Letters. Roč. 111, č. 23 (2013), s. 232302. ISSN 0031-9007. E-ISSN 1079-7114
Grant CEP: GA MŠMT(CZ) LG13031
Institucionální podpora: RVO:68378271 ; RVO:61389005
Klíčová slova: heavy ion collisions * quark-gluon plasma * ALICE
Kód oboru RIV: BG - Jaderná, atomová a mol. fyzika, urychlovače; BF - Elementární částice a fyzika vys. energií (FZU-D)
Impakt faktor: 7.728, rok: 2013

The directed flow of charged particles at midrapidity is measured in Pb-Pb collisions at root s(NN) p 2: 76 TeV relative to the collision symmetry plane defined by the spectator nucleons. A negative slope of the rapidity-odd directed flow component with approximately 3 times smaller magnitude than found at the highest RHIC energy is observed. This suggests a smaller longitudinal tilt of the initial system and disfavors the strong fireball rotation predicted for the LHC energies. The rapidity-even directed flow component is measured for the first time with spectators and found to be independent of pseudorapidity with a sign change at transverse momenta p(T) between 1.2 and 1: 7 GeV/c. Combined with the observation of a vanishing rapidity-even p(T) shift along the spectator deflection this is strong evidence for dipolelike initial density fluctuations in the overlap zone of the nuclei. Similar trends in the rapidity-even directed flow and the estimate from two-particle correlations at midrapidity, which is larger by about a factor of 40, indicate a weak correlation between fluctuating participant and spectator symmetry planes. These observations open new possibilities for investigation of the initial conditions in heavy-ion collisions with spectator nucleons.
Trvalý link: http://hdl.handle.net/11104/0231192