QCD correction to gluino decay to $t\bar{t}{\tilde{\chi }}_1^0$ in the MSSM

Abstract

We calculate the complete next-to-leading order QCD corrections to the three-body decay of gluino into top-pair associated with a lightest neutralino in the minimal supersymmetric standard model. We obtain that the LO and NLO QCD corrected decay widths of $\tilde{g}\to t\bar{t}{\tilde{\chi }}_1^0$ at the $SPS6$ benchmark point are $0.1490GeV$ and 0.1069 GeV respectively, and the relative correction is -28.2%. We investigate the dependence of the QCD correction to $\tilde{g}\to t\bar{t}{\tilde{\chi }}_1^0$ on $\tan \beta$ and the masses of gluino, scalar top quarks and the lightest neutralino around the $SPS6$ benchmark point, separately. We find that the NLO QCD corrections suppress the LO decay width, and the absolute relative correction can exceed 30% in some parameter space. Therefore, the QCD corrections to the three-body decay $\tilde{g}\to t\bar{t}{\tilde{\chi }}_1^0$ should be taken into account for the precise experimental measurement at future colliders. Moreover, we study the distributions of the top-pair invariant mass ($M_{t\bar{t}}$) and the missing energy ($E^{miss}$), and find that the line shapes of the LO distributions of $M_{t\bar{t}}$ and $E^{miss}$ are not obviously distorted by the NLO QCD corrections.

23 pages, 10 figures

References in corpus (2)

• Scalar one-loop 4-point integrals
• SUSY QCD one-loop effects in (un)polarized top-pair production at hadron colliders