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

• Autor(a) principal: Acharya, Shreyasi
• Data de Publicação: 2017
• Outros Autores: Gay Ducati, Maria Beatriz, Pereira, Luis Gustavo, Pezzi, Rafael Peretti, ALICE Collaboration
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/181523
• topic: Aceleradores de partículas; Colisao de ions pesados; Colisões proton-proton; Producao de mesons

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 newsingle-cluster, shower-shape based method was developed for the identification of highpT 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.