Observation of nuclear modifications in W-+/- boson production in pPb collisions at root s(NN)=8.16 TeV

• Main Authors: Sirunyan, A. M., Tumasyan, A. R., Adam, Wolfgang, Ambrogi, Federico, Asilar, Ece, Md. Ali, Mohd. Adli
• Format: Article
• Language: English; English; English
• Published: Elsevier 2020
• Subjects: QC Physics
• Online Access: http://irep.iium.edu.my/88866/1/88866_Observation%20of%20nuclear%20modifications%20_article.pdf; http://irep.iium.edu.my/88866/2/88866_Observation%20of%20nuclear%20modifications%20_scopus.pdf; http://irep.iium.edu.my/88866/3/88866_Observation%20of%20nuclear%20modifications%20_wos.pdf; http://irep.iium.edu.my/88866/; https://reader.elsevier.com/reader/sd/pii/S0370269319307701?token=7639A92B6025BAB0BC01649FEBA2C9A0BBBAC59763F06834DB4D2AB235726A642F629147C9A7A207D8636EA54F162A06

The production of W± bosons is studied in proton-lead (pPb) collisions at a nucleon-nucleon centreof-mass energy of √sNN = 8.16 TeV. Measurements are performed in the W± → μ±νμ channel using a data sample corresponding to an integrated luminosity of 173.4 ± 6.1 nb−1, collected by the CMS Collaboration at the LHC. The number of positively and negatively charged W bosons is determined separately in the muon pseudorapidity region in the laboratory frame |ημ lab| < 2.4 and transverse momentum pμ T > 25 GeV/c. The W± boson differential cross sections, muon charge asymmetry, and the ratios of W± boson yields for the proton-going over the Pb-going beam directions are reported as a function of the muon pseudorapidity in the nucleon-nucleon centre-of-mass frame. The measurements are compared to the predictions from theoretical calculations based on parton distribution functions (PDFs) at next-to-leading-order. The results favour PDF calculations that include nuclear modifications and provide constraints on the nuclear PDF global fits.