$T$-odd quark pair production and decay at $\gamma \gamma$ collider in the littlest Higgs model with $T$ parity in next-to-leading order QCD

TL;DR

This paper computes the next-to-leading order QCD corrections for T-odd mirror quark pair production at a gamma-gamma collider within the littlest Higgs model with T-parity, highlighting phase space effects and potential for experimental detection.

Contribution

It provides the first complete NLO QCD correction calculation for T-odd mirror quark pair production in the LHT model at gamma-gamma colliders, including decay and kinematic distributions.

Findings

NLO QCD corrections significantly alter LO cross sections.

K-factor increases near the production threshold.

Proper kinematic cuts can distinguish signals from Standard Model backgrounds.

Abstract

We calculate the complete next-to-leading order (NLO) QCD corrections to the $T$-odd mirror quark pair ($q_-\bar q_-=u_-\bar u_-$, $c_-\bar c_-$, $d_-\bar d_-$, $s_-\bar s_-$) production in the littlest Higgs model with $T$-parity (LHT) at a high energy $\gamma \gamma$ collider. We present the dependence of the leading order (LO) and NLO QCD corrected cross sections on the colliding energy $\sqrt{s}$. Our calculation includes the subsequent full weak decays of the final $T$-odd mirror quarks by adopting the narrow width approximation and the exclusive 2-jet event selection criterion. We provide the LO and QCD NLO kinematic distributions of final particles. We find that the NLO QCD correction is phase space dependent and modifies the LO cross section evidently. The $K$-factor increases noticeably when $\sqrt{s}$ approaches the threshold of the on-shell $q_-$-pair production. We conclude that it is possible to separate the signature of the $T$-odd quark pair production from possible Standard Model background by taking proper kinematic cut.