Diffractive pQCD mechanisms of exclusive production of $b \bar b$ dijets and $W^+ W^-$ pairs in proton-proton collisions

TL;DR

This paper analyzes the mechanisms behind exclusive production of $b ar b$ dijets and $W^+ W^-$ pairs in proton-proton collisions at the LHC, comparing QED and QCD contributions and exploring implications for new physics searches.

Contribution

It introduces a detailed calculation of diffractive QCD mechanisms for $W^+ W^-$ production using the Durham model, highlighting the small diffractive contribution relative to QED processes.

Findings

QED $ o W^+ W^-$ contribution is about 100 fb

Diffractive QCD contribution is only a small fraction of fb

Results suggest potential for new physics searches via anomalous couplings

Abstract

We discuss central exclusive production of $W^+W^-$ pairs in proton-proton collisions at LHC. Predictions for the total cross section and differential distributions in transverse momentum of $W^{\pm}$ and $WW$ invariant mass are presented. We discuss both $\gamma \gamma \to W^+ W^-$ mechanism as well as a new mechanism of exclusive diffractive production. The amplitude for the latter process is calculated in the Durham model. We compare the two (QED and QCD) types of contributions. The diffractive contribution is only a small fraction of fb compared to the $\gamma \gamma$ contribution which is of the order of 100 fb. This opens a possibility of searches for anomalous four-boson $\gamma \gamma W^+ W^-$ coupling due to physics beyond Standard Model.