Seeking leptoquarks in the $\bf t\bar{t}$ plus missing energy channel at the high-luminosity LHC

TL;DR

This paper proposes a search strategy for third-generation leptoquarks in the top-antitop plus missing energy channel at the high-luminosity LHC, assessing its potential to exclude or discover such particles up to nearly 2 TeV.

Contribution

It introduces a new search approach using top tagging and observables to differentiate scalar and vector leptoquarks at the HL-LHC.

Findings

Vector LQ can be excluded up to 1.96 TeV

Scalar LQ can be excluded up to 1.54 TeV

Several observables can distinguish LQ types in future discoveries

Abstract

The $t\bar t$ plus missing energy channel is one of the most efficient to detect third-generation leptoquarks (LQs). It offers an important test to models which explain flavor anomalies in $B$ meson decays. We outline a search strategy in the channel, relying on tagging the tops and on observables constructed out of the tops, and we assess the reach on LQs of the future high-luminosity LHC program. We find that with 3 ab$^{-1}$ a vector (scalar) LQ decaying 50% (100%) to top and neutrino can be excluded up to masses of 1.96 TeV (1.54 TeV). We also indicate several observables that, in case of a future discovery in the channel, can be used to distinguish a scalar LQ from a vector LQ. The implications of our findings to models addressing the recent flavor anomalies are finally discussed.