# Search for long-lived particles using nonprompt jets and missing transverse momentum with proton-proton collisions at $\sqrt{s} =$ 13 TeV

## TL;DR

This paper reports a search for long-lived particles decaying into displaced jets and missing energy using CMS data, setting new limits on gluino masses for various decay lengths in a supersymmetry model.

## Contribution

It introduces a novel search method utilizing CMS calorimeter timing to identify nonprompt jets and provides the most stringent limits to date on gluino masses with long decay lengths.

## Key findings

- No excess over background observed.
- Excluded gluino masses up to 2500 GeV for certain decay lengths.
- Established the best limits for gluinos with decay lengths > 0.5 m.

## Abstract

A search for long-lived particles decaying to displaced, nonprompt jets and missing transverse momentum is presented. The data sample corresponds to an integrated luminosity of 137 fb$^{-1}$ of proton-proton collisions at a center-of-mass energy of 13 TeV collected by the CMS experiment at the CERN LHC in 2016-2018. Candidate signal events containing nonprompt jets are identified using the timing capabilities of the CMS electromagnetic calorimeter. The results of the search are consistent with the background prediction and are interpreted using a gauge-mediated supersymmetry breaking reference model with a gluino next-to-lightest supersymmetric particle. In this model, gluino masses up to 2100, 2500, and 1900 GeV are excluded at 95% confidence level for proper decay lengths of 0.3, 1, and 100 m, respectively. These are the best limits to date for such massive gluinos with proper decay lengths greater than $\sim$0.5 m.