Exclusive photon-photon production of muon pairs in proton-proton collisions at sqrt(s) = 7 TeV

TL;DR

This paper reports the first measurement of exclusive muon pair production via photon-photon fusion in proton-proton collisions at 7 TeV, confirming theoretical predictions within uncertainties.

Contribution

It provides the first experimental measurement of the cross section for exclusive muon pair production in proton-proton collisions at 7 TeV, validating photon-photon fusion models.

Findings

Measured cross section of 3.38 pb with uncertainties.

Distribution shapes agree with theoretical predictions.

Ratio to predicted cross section is approximately 0.83.

Abstract

A measurement of the exclusive two-photon production of muon pairs in proton-proton collisions at sqrt(s)= 7 TeV, pp to p mu^+ mu^- p, is reported using data corresponding to an integrated luminosity of 40 inverse picobarns. For muon pairs with invariant mass greater than 11.5 GeV, transverse momentum pT(mu) > 4 GeV and pseudorapidity |eta(mu)| < 2.1, a fit to the dimuon pt(mu^+ mu^-) distribution results in a measured cross section of sigma(pp to p mu^+ mu^- p) = 3.38 [+0.58 -0.55] (stat.) +/- 0.16 (syst.) +/- 0.14 (lumi.) pb, consistent with the theoretical prediction evaluated with the event generator Lpair. The ratio to the predicted cross section is 0.83 [+0.14-0.13] (stat.) +/- 0.04 (syst.) +/- 0.03 (lumi.). The characteristic distributions of the muon pairs produced via photon-photon fusion, such as the muon acoplanarity, the muon pair invariant mass and transverse momentum agree with those from the theory.