Production of pi(0) and eta mesons up to high transverse momentum in pp collisions at 2.76 TeV

Acharya S., Adamova D., Aggarwal M. M., Rinella G. A., Agnello M., Agrawal N., ...More

EUROPEAN PHYSICAL JOURNAL C, vol.77, no.5, 2017 (SCI-Expanded) identifier identifier identifier


The invariant differential cross sections for inclusive pi(0) and eta mesons at midrapidity were measured in pp collisions at root 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 newsingle-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 pi(0), and between 30-50% for the. 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 pi(0) and eta meson production.