Neutral pion and eta meson measurements with the ALICE detector

Workshop for young scientists on the physics of ultrarelativistic nucleus-nucleus collisions 2016

Matyja, Adam^1,2

University of Tennessee, Knoxville

TN, United States^1

Institute of Nuclear Physics, PAN, Cracow, Poland^2

关键词: Electromagnetic calorimeter;    Hadron correlations;    Heavy ion collision;    Inner tracking system;    Modification factors;    Nuclear modification factors;    Quark-gluon plasma;    Time projection chambers;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/832/1/012011/pdf
DOI  :  10.1088/1742-6596/832/1/012011

来源: IOP

【 摘 要 】

The ALICE experiment at the LHC is optimized to study the quark-gluon plasma (QGP), created in heavy-ion collisions. The medium-induced energy loss of particles can be investigated via the measurement of neutral meson spectra in heavy-ion collisions as well as via neutral meson-hadron correlations. Neutral mesons are identified from decay photon pairs via the invariant mass technique. Photons are measured in ALICE directly in the two electromagnetic calorimeters (PHOS and EMCal), as well as via the method of photon conversion (PCM) into electron-positon pairs, where the latter are measured in the inner tracking system (ITS) and the time projection chamber (TPC). Results obtained from EMCal, PHOS and PCM are consistent and allow measurements of spectra with high precision over a wide kinematical range. Suppression of the high-pTmeson production is observed through the mesasurement of nuclear modification factor (RAA), which decreases with increasing the centrality of the collision. The suppression of the per-trigger yield on the away side in high-pTπ0hadron correlations as measured by the modification factor (IAA) also shows evidence for parton energy loss in the medium.