Inclusive and exclusive diffractive production of dilepton pairs in proton-proton collisions at high energies

TL;DR

This paper calculates and compares various diffractive and exclusive dilepton production processes in high-energy proton-proton collisions, revealing their relative magnitudes and potential backgrounds for luminosity measurements at the LHC.

Contribution

First calculation of cross sections for inclusive, single, central, and exclusive diffractive dilepton production in proton-proton collisions using diffractive parton distributions.

Findings

Inclusive single-diffractive Drell-Yan is about 100 times smaller than the ordinary Drell-Yan process.

Central-diffractive processes are an order of magnitude smaller than single-diffractive processes.

Photon-pomeron and pomeron-photon processes can dominate over photon-photon in certain phase space regions.

Abstract

We calculate for the first time cross sections for single and central diffractive as well as exclusive diffractive production of dilepton pairs in proton-proton collisions. Several differential distributions are shown. The inclusive diffractive processes are calculated using diffractive parton distributions extracted from the analysis of diffractive structure function and dijet production at HERA. We find that the inclusive single-diffractive Drell-Yan process is by about 2 orders of magnitude smaller than ordinary Drell-Yan process. The central-diffractive processes are smaller by one order of magnitude compared to single-diffractive ones. We consider also exclusive production of dilepton pairs. The exclusive photon-pomeron (pomeron-photon) process constitutes a background to the QED photon-photon process proposed to be used for controlling luminosity at LHC. Both processes are compared then in several differential distributions. We find a region of the phase space where the photon-pomeron or pomeron-photon contributions can be larger than the photon-photon one.