Gluons to Diphotons via New Particles with Half the Signal's Invariant Mass

Gluons to Diphotons via New Particles with Half the Signal’s Invariant Mass

Dongjin Chway, Radovan Dermíšek, Tae Hyun Jung, and Hyung Do Kim

Phys. Rev. Lett. 117, 061801 – Published 5 August 2016

Abstract

Any new particle charged under $S U (3)_{C}$ and carrying an electric charge will leave an imprint in the diphoton invariant mass spectrum, as it can mediate the $g g \to γ γ$ process through loops. The combination of properties of loop functions, threshold resummation, and gluon parton distribution functions can result in a peaklike feature in the diphoton invariant mass around twice the mass of a given particle even if the particle is short lived, and thus it does not form a narrow bound state. Using a recent ATLAS analysis, we set upper limits on the combined $S U (3)_{C}$ and electric charge of new particles and indicate future prospects. We also discuss the possibility that the excess of events in the diphoton invariant mass spectrum around 750 GeV originates from loops of a particle with a mass of around 375 GeV.

Received 1 May 2016

DOI:https://doi.org/10.1103/PhysRevLett.117.061801

Physics Subject Headings (PhySH)

Leptonic, semileptonic & radiative decays Particle production

Hypothetical fermions Hypothetical scalars

Particles & Fields

Authors & Affiliations

Dongjin Chway^1,*, Radovan Dermíšek^1,2,†, Tae Hyun Jung^1,‡, and Hyung Do Kim^1,§

¹Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747, Korea
²Physics Department, Indiana University, Bloomington, Indiana 47405, USA