Production of π0 and η mesons up to high transverse momentum in pp collisions at 2.76 TeV

Summary, in English

The invariant differential cross sections for inclusive π0 and η mesons at midrapidity were measured in pp collisions at s=2.76 TeV for transverse momenta 0.4 < pT< 40 GeV/c and 0.6 < pT< 20 GeV/c, respectively, using the ALICE detector. This large range in pT was achieved by combining various analysis techniques and different triggers involving the electromagnetic calorimeter (EMCal). In particular, a new single-cluster, shower-shape based method was developed for the identification of high-pT neutral pions, which exploits that the showers originating from their decay photons overlap in the EMCal. Above 4 GeV/c, the measured cross sections are found to exhibit a similar power-law behavior with an exponent of about 6.3. Next-to-leading-order perturbative QCD calculations differ from the measured cross sections by about 30% for the π0, and between 30–50% for the η meson, while generator-level simulations with PYTHIA 8.2 describe the data to better than 10–30%, except at pT< 1 GeV/c. The new data can therefore be used to further improve the theoretical description of π0 and η meson production. © 2017, CERN for the benefit of the ALICE collaboration.

• Author: S Acharya; D. Adamova; M.M Aggarwal; G Aglieri Rinella; M. Agnello; N Agrawal; Peter Christiansen; Martin Ljunggren; Anders Oskarsson; Tuva Richert; David Silvermyr; Evert Stenlund; Vytautas Vislavicius
• Department/s: Particle and nuclear physics
• Publishing year: 2017
• Language: English
• Publication/Series: European Physical Journal C
• Volume: 77
• Issue: 5
• Links: http://dx.doi.org/10.1140/epjc/s10052-017-4890-x
• Document type: Journal article
• Publisher: Springer Nature
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 1434-6044