Eur. Phys. J. C (2009) 62: 197-201
https://doi.org/10.1140/epjc/s10052-009-1034-y

Regular Article - Experimental Physics

ALICE-PHOS: acceptance and efficiency correction factors p−p→π ⁰+X at 10 TeV

SUBATECH, Ecole des Mines de Nantes, Université de Nantes, CNRS/IN2P3, 4 rue Alfred Kastler, 44307, Nantes, France

^* e-mail: lamia.benhabib@subatech.in2p3.fr

Received: 30 September 2008
Revised: 17 March 2009
Published online: 28 April 2009

Abstract

In ultra-relativistic Heavy-Ion Collisions (HIC), the properties of the quark gluon plasma (QGP) can be explored, in particular, via measurements of neutral pions. The π ⁰ is an important probe for both proton and heavy ion physics. In the former case, π ⁰ production provides an important mean of testing pQCD as well as useful data to constrain current and future theoretical models. In the latter case, π ⁰ measurements will serve as a baseline for exploring the nature of the HIC hard scattering. In the ALICE experiment, π ⁰ mesons are identified as they decay into two photons (π ⁰→γ γ) using the high-resolution photon spectrometer (PHOS). PHOS will measure π ⁰ transverse momentum over a wide range, from hundreds of MeV/c to several tens of GeV/c. An estimation of π ⁰ production cross-section in proton–proton collisions is calculated in a next-to-leading order (NLO) approximation and first presented. The π ⁰ geometrical acceptance and the identification efficiency along with the analysis on the invariant mass are the two important correction factors for obtaining a realistic π ⁰ spectrum discussed in this paper.