Interpreting the CMS $\ell^+\ell^- jj E\!\!\!\!/_{\rm T}$ Excess with a Leptoquark Model

TL;DR

This paper explains the CMS $ ext{ll} jj E_T^{miss}$ excess using a leptoquark model with dark matter, fitting observed event rates and distributions, and makes predictions for future LHC runs and dark matter detection.

Contribution

It demonstrates that leptoquark decays into dark matter can account for the CMS excess in $ ext{ll} jj E_T^{miss}$, extending previous models to explain multiple anomalies.

Findings

Leptoquark decay into dark matter fits the CMS excess data.

The model reproduces the di-lepton invariant mass distribution.

Predictions are made for 14 TeV LHC and dark matter detection prospects.

Abstract

Motivated by excesses in $ee jj$ and $e\nu jj$ channels observed by the CMS collaboration, in 8 TeV LHC data, a model of lepto-quarks with mass around 500 GeV was proposed in the literature. In order to reproduce the claimed event rate, lepto-quarks were assumed to have a significant partial branching ratio into an extra sector, taken to be Dark Matter, other than the canonical $ej$. We here show that the decay channel of lepto-quark into Dark Matter can fit another excess claimed by CMS, in $\ell^+\ell^- jj E\!\!\!\!/_{\rm T}$: the event rate, the distribution in di-lepton invariant mass and the rapidity range are compatible with the data. We provide predictions for the forthcoming Run II of the 14 TeV LHC and discuss aspects of dark matter detection.