Diffractive pQCD mechanism of exclusive production of $W^+ W^-$ pairs in proton-proton collisions

TL;DR

This paper investigates the exclusive production of W+W- pairs in proton-proton collisions at the LHC, comparing photon-photon and diffractive gluon-gluon mechanisms, highlighting the potential for new physics searches.

Contribution

It introduces a new diffractive mechanism involving gluon fusion with intermediate Higgs and quark loops, and compares its significance to the photon-photon process in exclusive W+W- production.

Findings

Diffractive gluon-gluon contribution is a small fraction of the photon-photon contribution.

Photon-photon mechanism dominates the exclusive W+W- production at the LHC.

Results suggest promising avenues for searching for anomalous couplings beyond the Standard Model.

Abstract

We present a study of central exclusive production of $W^+W^-$ pairs in proton-proton collisions at the LHC. We compare the contribution of the $\gamma \gamma \to W^+ W^-$ mechanism with a new mechanism of exclusive diffractive production through the $gg \to W^+ W^-$ subprocess with intermediate virtual Higgs boson and quark box diagrams. The amplitude for the latter process is expressed in terms of the off-diagonal unintegrated gluon distribution functions. Several observables related to this process are calculated. The phase space integrated diffractive contribution when separated is only a small fraction of fb compared to 115.4 fb of the $\gamma\gamma$-contribution without absorption. This opens a possibility of efficient searches for anomalous boson $\gamma W^+ W^-$ and $\gamma \gamma W^+ W^-$ couplings due to new physics beyond Standard Model.