Vector Leptoquarks and the 750 GeV Diphoton Resonance at the LHC

TL;DR

This paper proposes a model with vector leptoquarks and a scalar singlet to explain the 750 GeV diphoton resonance and lepton non-universality anomalies, aligning with experimental constraints and ruling out some scalar-only models.

Contribution

It introduces a unified model extending the Standard Model with vector leptoquarks and a scalar singlet to explain multiple anomalies simultaneously.

Findings

Identifies parameter space consistent with the 750 GeV resonance and experimental constraints.

Derives constraints on scalar-only BSM models explaining the resonance.

Shows certain scalar models are ruled out by current data.

Abstract

The ATLAS and CMS collaborations recently presented evidence of a resonance decaying to pairs of photons around 750 GeV. In addition, the BaBar, Belle, and LHCb collaborations have evidence of lepton non-universality in the semileptonic decays of $B$ mesons. In this work, we make a first step towards a unified explanation of these anomalies. Specifically, we extend the Standard Model by including vector leptoquarks and a scalar singlet that couples linearly to pairs of the leptoquarks. We find there is parameter space that gives the correct cross section for a putative 750 GeV resonance decaying to photons that is consistent with unitarity, measurements of the properties of the 125 GeV Higgs boson, and direct searches for resonances in other channels. In addition, we also show that constraints can be derived on any Beyond the Standard Model explanation of the 750 GeV resonance where the only new particles are scalars, which are strong enough to rule out certain types of models entirely.