Search for long-lived charged particles using the CMS detector in Run-2

TL;DR

This paper reports a search for long-lived charged particles at the LHC using CMS detector data from 2017-2018, employing a novel background prediction method based on ionization measurements to identify potential signals of new physics.

Contribution

It introduces a new background estimation technique using independent ionization variables and interprets results across multiple theoretical models of long-lived particles.

Findings

No significant excess observed, setting limits on particle masses.

Constraints placed on models with staus, stops, gluinos, and multiply charged particles.

First application of this ionization-based background prediction method in CMS long-lived particle searches.

Abstract

Long-lived charged particles are predicted by various theories beyond the Standard Model, leading to unique signatures that could reveal new physics. At the LHC, the CMS detector enables searches for these massive particles, identifiable by their characteristic ionization patterns. Using data collected during 2017-2018, we search for signals of anomalous ionization in the silicon tracker. We present a novel approach to background prediction, utilizing the distinct ionization measurements of the silicon pixel and strip detectors as independent variables. We interpret the results within several models including those with staus, stops, gluinos, and multiply charged particles as well as a new model with decays from a Z' boson