QCD correction to gluino decay to t t ¯ χ ~ 0 1 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
g
~
→t
t
¯
χ
~
0
1
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
g
~
→t
t
¯
χ
~
0
1
on
tanβ
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
g
~
→t
t
¯
χ
~
0
1
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
t
¯
) and the missing energy (
E
miss
), and find that the line shapes of the LO distributions of
M
t
t
¯
and
E
miss
are not obviously distorted by the NLO QCD corrections.