Macroscopic strings and ``quirks'' at colliders

Abstract

We consider extensions of the standard model containing additional heavy particles ("quirks") charged under a new unbroken non-abelian gauge group as well as the standard model. We assume that the quirk mass m is in the phenomenologically interesting range 100 GeV-TeV, and that the new gauge group gets strong at a scale Λ < m. In this case breaking of strings is exponentially suppressed, and quirk production results in strings that are long compared to Λ −1 . The existence of these long stable strings leads to highly exotic events at colliders. For 100 eV < ∼ Λ < ∼ keV the strings are macroscopic, giving rise to events with two separated quirk tracks with measurable curvature toward each other due to the string interaction. For keV < ∼ Λ < ∼ MeV the typical strings are mesoscopic: too small to resolve in the detector, but large compared to atomic scales. In this case, the bound state appears as a single particle, but its mass is the invariant mass of a quirk pair, which has an event-by-event distribution. For MeV < ∼ Λ < ∼ m, the strings are microscopic, and the quirks annihilate promptly within the detector. For colored quirks, this can lead to hadronic fireball events with ∼ 10 3 hadrons with energy of order GeV emitted in conjunction with hard decay products from the final annihilation. arXiv:0805.4642v3 [hep-ph]

Chiral quirkonium decays

“…This is unlike the original model, Ref. [1], where quirks acquired "vector-like" masses independently of electroweak symmetry breaking. We are motivated in part by the discovery that chiral quirks bound in quirky baryons can lead to a viable asymmetric dark matter candidate [10].…”

“…Quirks are fermions transforming under the SM gauge group along with a new strongly-coupled "infracolor" group SU (N ) ic [1]. (Earlier ideas were also considered in Ref.…”

“…Quirks pairs produced in a collider remain in a bound state even when produced with large kinetic energies. This leads to several interesting collider physics and dark matter applications [1,[3][4][5][6][7][8][9][10][11][12][13][14]. (Other work on hidden valley models can be found in [15][16][17].)…”

“…Ref. [1] estimated the suppression factor in the annihilation probability scaling as (β/L) L+1 /L, where β is the quirk relative velocity and L > 0. Therefore, instead of annihilating immediately, the quirky bound states are expected to emit soft radiation to shed their angular momentum.…”

“…Therefore, instead of annihilating immediately, the quirky bound states are expected to emit soft radiation to shed their angular momentum. 1 As the quirky bound state reaches a low angular momentum state (L ∼ 1), the constituent quirks ultimately annihilate; some quirky meson decay rates for certain vector-like quirks have been discussed in [1,3,4,14]. This paper is organized as follows.…”