Search for new fermions ("quirks") at the Fermilab Tevatron Collider

TL;DR

This paper reports a search for hypothetical particles called quirks with unusual ionization signatures in collider data, setting new mass limits and exploring beyond Standard Model physics.

Contribution

It presents the first dedicated search for quirks with high ionization in collider events, establishing new mass constraints and probing scenarios with extra QCD-like sectors.

Findings

No evidence of quirks was observed.

Set a lower mass limit of 107 GeV for charged quirks.

Explored scenarios with various strong dynamics scales.

Abstract

We report results of a search for particles with anomalously high ionization in events with a high transverse energy jet and large missing transverse energy in $2.4$ fb$^{-1}$ of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron $p\bar{p}$ collider. Production of such particles (quirks) is expected in scenarios with extra QCD-like {\it SU(N)} sectors, and this study is the first dedicated search for such signatures. We find no evidence of a signal and set a lower mass limit of 107 ~GeV for the mass of a charged quirk with strong dynamics scale $\Lambda$ in the range from 10 keV to 1 MeV.