Study of W boson production in pPb collisions at sqrt(s[NN]) = 5.02 TeV

TL;DR

This paper reports the first measurements of W boson production in proton-lead collisions at 5.02 TeV, revealing deviations from existing parton distribution models and highlighting the importance of including W data in nuclear PDFs.

Contribution

It provides the inaugural measurement of W boson production in pPb collisions, offering new data to improve nuclear parton distribution functions.

Findings

Deviations from current parton distribution function predictions

Measured W boson differential cross sections and asymmetries

Indicates the need to incorporate W data into global PDF fits

Abstract

The first study of W boson production in pPb collisions is presented, for bosons decaying to a muon or electron, and a neutrino. The measurements are based on a data sample corresponding to an integrated luminosity of 34.6 inverse nanobarns at a nucleon-nucleon centre-of-mass energy of sqrt(s[NN]) = 5.02 TeV, collected by the CMS experiment. The W boson differential cross sections, lepton charge asymmetry, and forward-backward asymmetries are measured for leptons of transverse momentum exceeding 25 GeV, and as a function of the lepton pseudorapidity in the abs(eta[lab]) < 2.4 range. Deviations from the expectations based on currently available parton distribution functions are observed, showing the need for including W boson data in nuclear parton distribution global fits.