Monojet signatures from gluino and squark decays

TL;DR

This paper investigates monojet and dijet signals at the LHC to search for squarks and gluinos within two supersymmetric scenarios, demonstrating significant impacts on exclusion limits through recast analyses of existing data.

Contribution

It introduces new monojet signatures from squark and gluino decays in two supersymmetric scenarios and assesses their impact on exclusion limits using recast LHC analyses.

Findings

Significant impact of associated squark-wino production on exclusion limits.

Distinctive monojet signatures from nearly degenerate squark-gluino pairs.

Non-trivial exclusion limits in the squark-gluino mass plane.

Abstract

We study the monojet and dijet channels at the LHC as a tool for searching for squarks and gluinos. We consider two separate R-parity conserving supersymmetric scenarios. In the first scenario we postulate a large mass hierarchy between squarks ($\tilde q$) and winos ($\widetilde W$), and wino-like neutralino is assumed to be the lightest supersymmetric particle (LSP). The associated squark-wino production, $pp \to \tilde q \widetilde W$, then leads to a monojet-like signature, where the high $p_T$ jet is originated from the squark decay, $\tilde q \to q + \widetilde W$. We demonstrate that this associated production, as well as the $pp \to \widetilde W \widetilde W + {\rm jets}$ production, have a significant impact on the exclusion limit in the squark-neutralino mass plane. The second scenario postulates that the lighter of the squark and gluino is only a few GeV heavier than the LSP neutralino. The associated squark-gluino production, $pp \to \tilde q \tilde g$, then leads to a distinctive monojet signature, where the high $p_T$ jet is produced from the decay of the heavier coloured particle into the lighter one ($\tilde q \to q + \tilde g$ for $m_{\tilde q} > m_{\tilde g}$ and $\tilde g \to q + \tilde q$ for $m_{\tilde g} > m_{\tilde q}$). The lighter coloured particle is effectively regarded as an invisible particle since the decay products are soft due to the approximate mass degeneracy. We recast existing monojet and dijet analyses and find a non-trivial exclusion limit in the squark-gluino mass plane in this scenario.