Semiexclusive dilepton production in proton-proton collisions with one forward proton measurement at the LHC

TL;DR

This paper investigates semiexclusive dilepton production in proton-proton collisions at the LHC, analyzing photon-photon fusion mechanisms with forward proton detection, and evaluates the impact of proton measurement cuts and gap survival factors.

Contribution

It introduces a detailed analysis of dilepton production mechanisms with forward proton detection, including the effects of measurement cuts and the use of the SuperChic generator for gap survival factors.

Findings

Gap survival factor varies with the dissociative process type.

Proton measurement cuts significantly influence distribution shapes.

The study establishes relationships between gap survival, invariant mass, and lepton pair kinematics.

Abstract

We discuss the mechanisms of photon-photon fusion triggering the dilepton production in proton-proton collisions with rapidity gap in the main detector and one forward proton in the forward proton detectors. This correspond to the LHC measurements made by ATLAS+AFP and CMS+PPS. Transverse momenta of the intermediate photons and photon fluxes expressed by the form factors and structure functions are included. Moreover the influence of proton measurement and cuts on the $\xi_{1/2}$, $M_{ll}$, $Y_{ll}$, $p_{t,ll}$ distributions, cross section and gap survival factor are considered for both double-elastic and single-dissociative processes. The analyzes used the SuperChic generator to calculate the soft gap survival factor and to compare the results obtained with its use to the results obtained on the owned codes available. It is shown that the gap survival factor for the single dissociative mechanism is related to the emission of a (mini)jet into the main detector depending on the type of contribution. The dependence between this value and the invariant mass as well as the transverse momentum of the leptons pair and its rapidity was also found.