A search for charged massive long-lived particles

TL;DR

This paper reports a search for charged massive long-lived particles using data from the Fermilab Tevatron, setting new mass exclusion limits for various hypothetical particles predicted by theories beyond the standard model.

Contribution

It introduces a novel search method for long-lived charged particles based on their unique speed and ionization signatures, and sets new mass exclusion limits.

Findings

Excluded gaugino-like charginos below 267 GeV

Excluded higgsino-like charginos below 217 GeV

Excluded scalar top quarks below 285 GeV

Abstract

We report on a search for charged massive long-lived particles (CMLLPs), based on 5.2 fb$^{-1}$ of integrated luminosity collected with the D0 detector at the Fermilab Tevatron $p\bar{p}$ collider. We search for events in which one or more particles are reconstructed as muons but have speed and ionization energy loss $(dE/dx)$ inconsistent with muons produced in beam collisions. CMLLPs are predicted in several theories of physics beyond the standard model. We exclude pair-produced long-lived gaugino-like charginos below 267 GeV and higgsino-like charginos below 217 GeV at 95% C.L., as well as long-lived scalar top quarks with mass below 285 GeV.