Azimuthally differential pion femtoscopy in Pb-Pb collisions at 2.76 TeV with ALICE at the LHC

作者：Loggins Vera^*

来源：Nuclear Physics A, 2014, 931: 1088-1092.

DOI：10.1016/j.nuclphysa.2014.08.061

• LHC
• ALICE
• Femtoscopy
• Radii oscillation
• Final eccentricity
• Freeze-out

Femtoscopy of non-central heavy-ion collisions provides access to information on the geometry of the effective pion-emitting source. In particular, the source shape can be studied by measuring femtoscopic radii as a function of the pion emission angle relative to the collision symmetry planes. We present the results of azimuthally differential femtoscopy of Pb-Pb collisions at root(NN)-N-S = 2.76 TeV at the LHC relative to the second harmonic event plane. We observe a clear oscillation of the extracted radii as a function of the emission angle. We find that R-side and R-out oscillate out of phase for all centralities and pion transverse momenta. The relative amplitude of R-side oscillation decreases in more central collisions, but remains positive, which indicates that the source remains out-of-plane extended qualitatively similar to what was observed at RHIC energies. We compare our results to existing hydrodynamical and transport model calculations.

• 出版日期2014-11