Probing a leptophobic top-colour model with cross section measurements and precise signal and background predictions: a case study

TL;DR

This paper evaluates the sensitivity of current LHC measurements to a leptophobic top-colour model, comparing different theoretical predictions and deriving exclusion limits, thus providing a comprehensive analysis of the model's viability.

Contribution

It introduces a detailed comparison of the leptophobic top-colour model against state-of-the-art SM predictions using the CONTUR framework, incorporating higher-order calculations for improved accuracy.

Findings

Current measurements constrain the model's parameter space.

Higher-order SM predictions affect the exclusion limits.

Comparison with resonance searches highlights complementary sensitivities.

Abstract

The sensitivity of particle-level fiducial cross section measurements from ATLAS, CMS and LHCb to a leptophobic top-colour model is studied. The model has previously been the subject of resonance searches. Here we compare it directly to state-of-the-art predictions for Standard Model top quark production and also take into account next-to-leading order predictions for the new physics signal. We make use of the CONTUR framework to evaluate the sensitivity of the current measurements, first under the default CONTUR assumption that the measurement and the SM exactly coincide, and then using the full SM theory calculation for $t\bar{t}$ at next-to-leading and next-to-next-to-leading order as the background model. We derive exclusion limits, discuss the differences between these approaches, and compare to the limits from resonance searches by ATLAS and CMS.