Modelling uncertainties and prompt b-jet identification in $t\bar{t}b\bar{b}$ production with dilepton signatures at the LHC

TL;DR

This paper presents advanced NLO QCD predictions for $t\bar{t}b\bar{b}$ production with dilepton signatures at the LHC, focusing on uncertainties and prompt $b$-jet identification to improve background modeling in Higgs analyses.

Contribution

It provides state-of-the-art off-shell NLO QCD calculations for $t\bar{t}b\bar{b}$ production, including uncertainty estimates and a new method for prompt $b$-jet categorization.

Findings

Quantified dominant theoretical uncertainties.

Assessed impact of off-shell effects on cross sections.

Proposed a kinematic method for prompt $b$-jet identification.

Abstract

As one of the primary backgrounds to $pp \to t\bar{t}H(H\to b\bar{b})$, the QCD process of $t\bar{t}b\bar{b}$ hadroproduction demands very accurate theoretical predictions and estimates of uncertainties. On top of that, the capacity of properly identifying prompt $b$-jets is beneficial for many analyses. In this contribution we discuss state-of-the-art predictions for $t\bar{t}b\bar{b}$ production with dilepton decays at the LHC, as obtained from full off-shell NLO QCD calculations. We evaluate the dominant uncertainties of the calculation and the impact of the off-shell effects on fiducial cross sections. Furthermore, we explore a kinematic prescription for the categorisation of prompt $b$-jets.