Search for supersymmetry in final states with charm jets and missing transverse momentum in 13 TeV $pp$ collisions with the ATLAS detector

TL;DR

This paper reports a search for supersymmetric particles decaying into charm jets and neutralinos using 13 TeV proton-proton collision data, setting mass exclusion limits up to 850 GeV for certain decay scenarios.

Contribution

First to analyze charm jet final states in supersymmetry searches at 13 TeV with the ATLAS detector, establishing new mass exclusion limits.

Findings

Excluded top and charm squarks up to 850 GeV for massless neutralino.

Excluded squarks up to 500 GeV for small mass differences with neutralino.

No significant excess observed over Standard Model predictions.

Abstract

A search for supersymmetric partners of top quarks decaying as $\tilde{t}_1\to c\tilde\chi^0_1$ and supersymmetric partners of charm quarks decaying as $\tilde{c}_1\to c\tilde\chi^0_1$, where $\tilde\chi^0_1$ is the lightest neutralino, is presented. The search uses 36.1 ${\rm fb}^{-1}$ $pp$ collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS experiment at the Large Hadron Collider and is performed in final states with jets identified as containing charm hadrons. Assuming a 100% branching ratio to $c\tilde\chi^0_1$, top and charm squarks with masses up to 850 GeV are excluded at 95% confidence level for a massless lightest neutralino. For $m_{\tilde{t}_1,\tilde{c}_1}-m_{\tilde\chi^0_1} <$100 GeV, top and charm squark masses up to 500 GeV are excluded.