Abstract

We present the first azimuthally differential measurements of the pion source size relative to the second harmonic event plane in Pb-Pb collisions at a center-of-mass energy per nucleon-nucleon pair of sqrt[s_NN]=2.76  TeV. The measurements have been performed in the centrality range 0%-50% and for pion pair transverse momenta 0.2<k_T<0.7  GeV/c. We find that the R_side and R_out radii, which characterize the pion source size in the directions perpendicular and parallel to the pion transverse momentum, oscillate out of phase, similar to what was observed at the Relativistic Heavy Ion Collider. The final-state source eccentricity, estimated via R_side oscillations, is found to be significantly smaller than the initial-state source eccentricity, but remains positive-indicating that even after a stronger expansion in the in-plane direction, the pion source at the freeze-out is still elongated in the out-of-plane direction. The 3+1D hydrodynamic calculations are in qualitative agreement with observed centrality and transverse momentum R_side oscillations, but systematically underestimate the oscillation magnitude.

Autore Pugliese

• Di Bari Domenico , Fiore Enrichetta Maria , Volpe Giacomo

Tutti gli autori

• DI BARI D.;FIORE E.M.;VOLPE G.;MAZZILLI M.

Titolo volume/Rivista

Non Disponibile

Anno di pubblicazione

2017

ISSN

0031-9007

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

Non Disponibile

Numero di citazioni Scopus

Non Disponibile

Ultimo Aggiornamento Citazioni

Non Disponibile

Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile