About the rapidity and helicity distributions of the W bosons produced at LHC

TL;DR

This paper discusses the characteristic distributions of leptons from W boson decays at the LHC, highlighting potential for precise measurement of W boson rapidity and helicity distributions based on decay asymmetries.

Contribution

It introduces a method to measure W boson rapidity and helicity distributions using decay lepton pseudorapidity distributions at the LHC.

Findings

Characteristic lepton pseudorapidity distributions depend on W helicity.

Potential for precise measurement of W polarization states at small transverse momentum.

Analysis of decay distributions can reveal W boson production dynamics.

Abstract

$W$ bosons are produced at LHC from a forward-backward symmetric initial state. Their decay to a charged lepton and a neutrino has a strong spin analysing power. The combination of these effects results in characteristic distributions of the pseudorapidity of the leptons decaying from $W^+$ and $W^-$ of different helicity. This observation may open the possibility to measure precisely the $W^+$ and $W^-$ rapidity distributions for the two transverse polarisation states of $W$ bosons produced at small transverse momentum.