New Physics at 1TeV?

S.I Godunov,V.A Andrianov,V.A Rubakov,M.D Fitkevich,A.A Andrianov,V.A Matveev,V.T Kim

doi:10.1051/epjconf/201612502009

Abstract

We consider the extension of the Standard Model with an extra scalar S which decays can be responsible for the diphoton excess with invariant mass ~ 750 GeV observed at the 13 TeV LHC run. Two scenarios of S production are considered: gluon fusion through a loop of heavy isosinglet quark(s) and photon fusion through a loop of heavy isosinglet leptons. In the second case many heavy leptons are needed or/and they should have large electric charges in order to reproduce experimental data on σ pp → sx ·Br( S → γγ )

Highlights

ATLAS and CMS collaborations recently announced a small enhancement over smooth background of two photon events with invariant mass 750 GeV [1, 2]
Though statistical significance of this enhancement is not large, it induced a whole bunch of theoretical papers devoted to its interpretation. The reason for this explosive activity is clear: maybe the Standard Model is changed at one TeV scale, and we are witnessing the first sign of New Physics
We analyze the possibility that the enhancement at 750 GeV diphoton invariant mass observed by ATLAS and CMS is due to decays of a new scalar S

Summary

Introduction

ATLAS and CMS collaborations recently announced a small enhancement over smooth background of two photon events with invariant mass 750 GeV [1, 2]. Though statistical significance of this enhancement is not large (within 3 standard deviations), it induced a whole bunch of theoretical papers devoted to its interpretation The reason for this explosive activity is clear: maybe the Standard Model is changed at one TeV scale, and we are witnessing the first sign of New Physics. Let us suppose that the observed enhancement is due to the γγ decay of a new particle It should be a boson with spin different from one: the simplest possibility is a scalar particle S with mS = 750 GeV. Nonzero hypercharges provide couplings of these particles with photon and Z-boson These particles can be quark(s) (color triplets) Ti or lepton(s) (color singlets) Li. These particles can be quark(s) (color triplets) Ti or lepton(s) (color singlets) Li They couple with S by Yukawa interactions with coupling constants λiT and λiL correspondingly.

Quarkophilic S

Leptophilic S

Conclusions