Searches for scalar leptoquarks in $pp$ collisions at $\sqrt{s}$ = 8 TeV with the ATLAS detector

TL;DR

This paper reports on searches for scalar leptoquarks in proton-proton collisions at 8 TeV using ATLAS data, setting mass exclusion limits up to around 1 TeV without observing any significant excess over the Standard Model.

Contribution

It provides new exclusion limits on scalar leptoquark masses across different generations using the full 8 TeV ATLAS dataset.

Findings

No significant excess observed in any channel.

Scalar leptoquarks are excluded up to 1050 GeV for first-generation.

Exclusion limits are set for second- and third-generation leptoquarks.

Abstract

Searches for pair-produced scalar leptoquarks are performed using 20 fb$^{-1}$ of proton-proton collision data provided by the LHC and recorded by the ATLAS detector at $\sqrt{s}=8$ TeV. Events with two electrons (muons) and two or more jets in the final state are used to search for first (second)-generation leptoquarks. The results from two previously published ATLAS analyses are interpreted in terms of third-generation leptoquarks decaying to $b\nu_{\tau}\bar{b}\bar{\nu_{\tau}}$ and $t\nu_{\tau}\bar{t}\bar{\nu_{\tau}}$ final states. No statistically significant excess above the Standard Model expectation is observed in any channel and scalar leptoquarks are excluded at 95% CL with masses up to $m_{\mathrm{LQ1}}$ < 1050 GeV for first-generation leptoquarks, $m_{\mathrm{LQ2}}$ < 1000 GeV for second-generation leptoquarks, $m_{\mathrm{LQ3}} < $ 625 GeV for third-generation leptoquarks in the $b\nu_{\tau}\bar{b}\bar{\nu_{\tau}}$ channel, and 200 $< m_{\mathrm{LQ3}} < $ 640 GeV in the $t\nu_{\tau}\bar{t}\bar{\nu_{\tau}}$ channel.