Fresh look at the LHC limits on vector leptoquarks

TL;DR

This paper provides updated and more accurate exclusion limits on vector leptoquarks at the LHC by considering all production mechanisms, interference effects, and the validity of the theoretical models, leading to improved constraints.

Contribution

It introduces comprehensive analysis including indirect production, interference effects, and mixed channels, significantly refining the LHC limits on vector leptoquarks compared to previous studies.

Findings

Interference effects can be constructive or destructive, affecting search sensitivity.

Including mixed production channels shifts mass exclusion limits.

High mass regime validity of the full theory is confirmed.

Abstract

Vector leptoquarks (vLQs) are popular candidates for searching for physics beyond the Standard Model. In this paper, we present updated exclusion limits on various vLQ species, accounting for all the relevant production mechanisms at the LHC. In particular, we highlight the critical role of indirect production and its interference with the Standard Model Drell-Yan process. This interference can be constructive or destructive, depending on the specific quantum numbers of the vLQ, and significantly impacts the sensitivity of current searches. Furthermore, we demonstrate that including QCD-QED mixed pair production channels leads to a noticeable shift in model-independent mass limits. Additionally, we examine the validity of the full theory with vLQs and corresponding effective operators in the high mass regime. Overall, our analysis yields a substantial improvement in the exclusion limits on vLQs compared to the existing results in the literature.