Production of ${\pi ^0}$ and $\eta $ mesons up to high transverse momentum in pp collisions at 2.76 TeV

• Published in: The European physical journal. C, Particles and fields Particles and fields, 2017-05, Vol.77 (5)
• Main Authors: Aiola, S., Anson, C., Arnold, O. W., Badalà, A., Baek, Y. W., Bathen, B., Batyunya, B., Betev, L., Bhat, I. R., Biswas, S., Bock, F., Borissov, A., Carena, F., Chujo, T., Cicalo, C., Dainese, A., Das, D., Dietel, T., Dönigus, B., Erazmus, B., Esumi, S., Fabbietti, L., Floris, M., Fokin, S., Garabatos, C., Graham, K. L., Grelli, A., Gronefeld, J. M., Herghelegiu, A., Herrmann, F., Hosokawa, R., Hughes, C., Hussain, T., Jacazio, N., Jahnke, C., Uysal, A. Karasu, Karayan, L., Keijdener, D. L. D., Khatun, A., Kirsch, S., Klein, J., Klewin, S., Kolojvari, A., La Rocca, P., Lien, J., Ljunggren, H. M., Loizides, C., Lopez, X., Lunardon, M., Pedreira, M. Martinez, Mas, A., Milano, L., Mitu, C. M., Moretto, S., Nyanin, A., Orava, R., Pagano, D., Pandey, A. K., Papikyan, V., Pareek, P., Passfeld, A., Da Costa, H. Pereira, Peskov, V., Pestov, Y., Petrov, V., Pinazza, O., Piyarathna, D. B., Porter, J., Pruneau, C. A., Putschke, J., Räsänen, S. S., Rascanu, B. T., Riabov, V., Sahoo, S., Saini, J., Schutz, Y., Shtejer, K., Siemiarczuk, T., Snellings, R. J. M., Soramel, F., Sorensen, S., Srivastava, B. K., Stenlund, E., Šumbera, M., Szczepankiewicz, A., Muñoz, G. Tejeda, Trubnikov, V., Tsuji, T., Uras, A., van Leeuwen, M., Veen, A. M., Vértesi, R., Vilakazi, Z., Wang, H., Wessels, J. P., Wilkinson, J., Williams, M. C. S., Windelband, B., Zampolli, C., Zhou, Z.
• Format: Article
• Language: English
• Subjects: PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
• ISSN: 1434-6044

The invariant differential cross sections for inclusive π 0 and η mesons at midrapidity were measured in pp collisions at √s=2.76 TeV for transverse momenta 0.4 < p T < 40 GeV/c and 0.6 < p T < 20 GeV/c, respectively, using the ALICE detector. This large range in p T was achieved by combining various analysis techniques and different triggers involving the electromagnetic calorimeter (EMCal). Particularly, a new single-cluster, shower-shape based method was developed for the identification of high-p T 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 π 0 , 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 p T < 1 GeV/c. The new data can therefore be used to further improve the theoretical description of π 0 and η meson production.