Journal Article

Z-boson production in p-Pb collisions at sNN = 8.16 TeV and Pb-Pb collisions at sNN = 5.02 TeV

Andrei, C., Albuquerque, D. S. D., Colamaria, F., Marchisone, M., Kurepin, A. B., Muhuri, S., Pan, J., Karavicheva, T., Fan, F., Horak, D., Dobrin, A., Bombara, M., Elia, D., Jacak, B., Rakotozafindrabe, A., De Pasquale, S., Garg, K., Putschke, J., Adamová, D., Nesterov, D., Keidel, R., Riabov, V., Sumberia, V., Ahmad, S., Gaardhøje, J. J., Lindner, A., Augustinus, A., Krizkova Gajdosova, K., Tumkin, A., Cicalo, C., Khan, S., Costanza, S., Jaelani, S., Oliver, M. H., Rosas, E. D., Ronchetti, F., Greiner, L., Kim, H., Hussain, N., Kiselev, S., Scomparin, E., Zhang, S., Das, D., Grigoriev, V., Petrovici, M., Chapeland, S., Iddon, J. P., Nandi, B. K., Haake, R., Skaali, T. B., Kuryakin, A., Matonoha, O., Deng, W., Majka, R. D., Margagliotti, G. V., Cosentino, M. R., Takahashi, J., Munhoz, M. G., Adolfsson, J., Giubellino, P., Shabanov, A., Jonas, F., Fecchio, P., Kim, J., Dash, S., Samsonov, V., Lévai, P., Loginov, V., Shabetai, A., Windelband, B., Ghosh, S. K., Vercellin, E., Murray, S., Vargas, A., Ravasenga, I., Kuijer, P. G., Pezzi, R. P., Jacobs, P. M., Figiel, J., Khan, A. M., Lesser, E. D., Völkl, M. A., Závada, P., Bielčík, J., Bhatt, H., Neumann,

2020

Overview

A bstract Measurement of Z-boson production in p-Pb collisions at s NN = 8 . 16 TeV and Pb-Pb collisions at s NN = 5 . 02 TeV is reported. It is performed in the dimuon decay channel, through the detection of muons with pseudorapidity − 4 < η μ < − 2 . 5 and transverse momentum p T μ > 20 GeV/ c in the laboratory frame. The invariant yield and nuclear modification factor are measured for opposite-sign dimuons with invariant mass 60 < m μμ < 120 GeV/ c 2 and rapidity 2 . 5 < y cms μμ < 4. They are presented as a function of rapidity and, for the Pb-Pb collisions, of centrality as well. The results are compared with theoretical calculations, both with and without nuclear modifications to the Parton Distribution Functions (PDFs). In p-Pb collisions the center-of-mass frame is boosted with respect to the laboratory frame, and the measurements cover the backward ( − 4 . 46 < y cms μμ < − 2 . 96) and forward (2 . 03 < y cms μμ < 3 . 53) rapidity regions. For the p-Pb collisions, the results are consistent within experimental and theoretical uncertainties with calculations that include both free-nucleon and nuclear-modified PDFs. For the Pb-Pb collisions, a 3 . 4 σ deviation is seen in the integrated yield between the data and calculations based on the free-nucleon PDFs, while good agreement is found once nuclear modifications are considered.

• Publisher: Springer Berlin Heidelberg
• Subject: Classical and Quantum Gravitation / Elementary Particles / Fysik / Natural Sciences / Naturvetenskap / Physical Sciences / Physics / Physics and Astronomy / Quantum Field Theories / Quantum Field Theory / Quantum Physics / Regular Article - Experimental Physics / Relativity Theory / String Theory / Subatomic Physics / Subatomär fysik