The production of a diphoton resonance via photon-photon fusion

TL;DR

This paper investigates the production of a 750 GeV diphoton resonance via photon-photon fusion at the LHC, providing precise calculations and exploring implications for new physics, including parity and CP violation effects.

Contribution

It offers a detailed calculation of photon-photon luminosity and cross sections, analyzing both inclusive and exclusive production modes with small theoretical uncertainties.

Findings

Photon-photon fusion can produce the 750 GeV resonance with measurable cross sections.

Exclusive production mode is sensitive to the resonance's parity and CP-violating effects.

Simple cuts can isolate photon-photon contributions from other fusion processes.

Abstract

Motivated by the recent LHC observation of an excess of diphoton events around an invariant mass of 750 GeV, we discuss the possibility that this is due to the decay of a new scalar or pseudoscalar resonance dominantly produced via photon-photon fusion. We present a precise calculation of the corresponding photon-photon luminosity in the inclusive and exclusive scenarios, and demonstrate that the theoretical uncertainties associated with these are small. In the inclusive channel, we show how simple cuts on the final state may help to isolate the photon-photon induced cross section from any gluon-gluon or vector boson fusion induced contribution. In the exclusive case, that is where both protons remain intact after the collision, we present a precise cross section evaluation and show how this mode is sensitive to the parity of the object, as well as potential $CP$-violating effects. We also comment on the case of heavy-ion collisions and consider the production of new heavy colourless fermions, which may couple to such a resonance.