Search for quantum black holes in lepton+jet final states using proton-proton collisions at $\sqrt{s}=13.6$ TeV with the ATLAS detector

TL;DR

This paper reports a search for quantum black holes in lepton+jet final states at 13.6 TeV using ATLAS data, setting new exclusion limits up to 9.4 TeV with no significant excess observed.

Contribution

First search for quantum black holes at 13.6 TeV with the ATLAS detector, establishing the strongest exclusion limits to date.

Findings

No significant excess above Standard Model background.

Excluded quantum black hole production up to 9.4 TeV.

Set 95% CL upper limits on cross-section times branching ratio.

Abstract

A search for quantum black holes in electron+jet or muon+jet final states with high invariant mass is performed. The analysis uses data from $\sqrt{s}=13.6~\textrm{TeV}$ $pp$ collisions recorded by the ATLAS detector between 2022 and 2024 during Run~3 of the Large Hadron Collider, corresponding to an integrated luminosity of $164~\mathrm{fb}^{-1}$. This search is strongly motivated by a dramatic increase of the production cross-section by up to an order of magnitude for the highest masses considered, thanks to the small increase of $0.6~\textrm{TeV}$ in centre-of-mass energy between Run~2 and Run~3. No significant excess above the Standard Model background is observed, and 95\% CL upper limits are set on the production cross-section times branching ratio in several benchmark models, reaching a mass scale of $9.4~\textrm{TeV}$. These represent the strongest exclusion limits to date on quantum black hole production.