Nuclear modification factor of light neutral-meson spectra up to high transverse momentum in p–Pb collisions at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"><mml:msqrt><mml:mrow><mml:msub><mml:mrow><mml:mi>s</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">NN</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:msqrt><mml:mo linebreak="goodbreak" linebreakstyle="after">=</mml:mo><mml:mn>8.16</mml:mn></mml:math> TeV
S. Acharya, D. Adamová, A. Adler, J. Adolfsson, G. Aglieri Rinella, M. Agnello, N. Agrawal, Z. Ahammed, S. Ahmad, S. U. Ahn, I. Ahuja, Zaenal Akbar, A. Akindinov, M. Al-Turany, S.N. Alam, D. Aleksandrov, B. Alessandro, H. M. Alfanda, R. Alfaro Molina, B. Ali, Y. Ali, A. Alici, N. Alizadehvandchali, A. Alkin, J. Alme, T. Alt, L. Altenkamper, I. Altsybeev, M. N. Anaam, C. Andrei, D. Andreou, A. Andronic, M. Angeletti, V. Anguelov, F. Antinori, P. Antonioli, C. Anuj, N. Apadula, L. Aphecetche, H. Appelshäuser, S. Arcelli, R. Arnaldi, I. C. Arsene, M. Arslandok, A. Augustinus, R. Averbeck, Sizar Aziz, M. D. Azmi, A. Badalá, Y. W. Baek, X. Bai, R. Bailhache, Y. Bailung, R. Bala, A. Balbino, A. Baldisseri, M. Ball, D. Banerjee, R. Barbera, L. Barioglio, M. Barlou, G. G. Barnaföldi, L. S. Barnby, V. Barret, C. Bartels, K. Barth, E. Bartsch, F. Baruffaldi, N. Bastid, S. Basu, G. Batigne, B. Batyunya, D. Bauri, J. L. Bazo Alba, I. G. Bearden, C. Beattie, I. Belikov, A. D. C. Bell Hechavarria, F. Bellini, R. Bellwied, S. Belokurova, V. Belyaev, G. Bencedi, S. Beolè, A. Bercuci, Y. Berdnikov, A. Berdnikova, D. Berényi, L. Bergmann, M. G. Besoiu, L. Betev, Partha Pratim Bhaduri, A. Bhasin, I. R. Bhat, M. A. Bhat, B. Bhattacharjee, P. Bhattacharya, L. Bianchi, N. Bianchi, J. Bielčík
Abstract
Neutral pion ( π 0 ) and η meson production cross sections were measured up to unprecedentedly high transverse momenta ( p T ) in p–Pb collisions at s NN = 8.16 TeV . The mesons were reconstructed via their two-photon decay channel in the rapidity interval − 1.3 < y < 0.3 in the ranges of 0.4 < p T < 200 GeV/ c and 1.0 < p T < 50 GeV/ c , respectively. The respective nuclear modification factor ( R pPb ) is presented for p T up to of 200 and 30 GeV/ c , where the former was achieved by extending the π 0 measurement in pp collisions at s = 8 TeV using the merged cluster technique. The values of R pPb are below unity for p T < 10 GeV/ c , while they are consistent with unity for p T > 10 GeV/ c , leaving essentially no room for final state energy loss. The new data provide strong constraints for nuclear parton distribution and fragmentation functions over a broad kinematic range and are compared to model predictions as well as previous results at s NN = 5.02 TeV .