Quirks at the Tevatron and Beyond

TL;DR

This paper explores quirky particles transforming under multiple gauge groups, proposing models that explain the Wjj excess observed by CDF, and analyzing their collider phenomenology and experimental constraints.

Contribution

It introduces a novel quirky model with specific scalar quirks that can account for collider anomalies and provides detailed calculations of production and decay processes.

Findings

Quirky models can naturally explain the Wjj excess.

Quirkonium decays produce gluon jets without b-jet components.

Potential new signals include dijet, multi-W, and monojet events.

Abstract

We consider the physics and collider phenomenology of quirks that transform nontrivially under QCD color, SU(2)_W as well as an SU(N)_{ic} infracolor group. Our main motivation is to show that the recent Wjj excess observed by CDF naturally arises in quirky models. The basic pattern is that several different quirky states can be produced, some of which beta-decay during or after spin-down, leaving the lightest electrically neutral quirks to hadronize into a meson that subsequently decays into gluon jets. We analyze LEP II, Tevatron, UA2, and electroweak precision constraints, identifying the simplest viable models: scalar quirks ("squirks") transforming as color triplets, SU(2)_W triplets and singlets, all with vanishing hypercharge. We calculate production cross sections, weak decay, spin-down, meson decay rates, and estimate efficiencies. The novel features of our quirky model includes: quirkonium decay proceeds into a pair of gluon jets, without a b-jet component; there is essentially no associated Zjj or gamma+jj signal; and there are potentially new (parameter-dependent) contributions to dijet production, multi-W production plus jets, W+gamma, gamma+gamma resonance signals, and monojet signals. There may be either underlying event from low energy QCD deposition resulting from quirky spin-down, and/or qualitatively modified event kinematics from infraglueball emission.