Stop decays in SUSY-QCD

Abstract

The partial widths are determined for stop decays to top quarks and gluinos, and gluino decays to stop particles and top quarks (depending on the masses of the particles involved). The widths are calculated including one-loop SUSY-QCD corrections. The radiative corrections for these strong-interaction decays are compared with the SUSY-QCD corrections for electroweak stop decays to quarks and neutralinos/charginos and top-quark decays to stops and neutralinos.Comment: 20 pages, LaTeX, 8 figures (uses epsfig). Complete postscript file available at http://rulgm4.LeidenUniv.nl/preprints.htm

Electroweak corrections to the decays of the top squark and gluino

“…The tree-level partial widths for the top squark and gluino decays,t 1,2 →g + t andg →t 1,2 + t as shown in Fig.1(a.1)-1(a.3), are given by [15]:…”

“…So the accurate calculations including quantum corrections for these decays are necessary. The largest radiative corrections for the squark-gluino sector in the MSSM are associated with the strong interaction, the relative SUSY-QCD corrections for the processt 2 →g + t can reach 35% and that forg →t 1 + t can reach −10% [15]. However, the investigation of the electroweak corrections for these processes is necessary in precise experimental measurement, since their electroweak corrections maybe also sizable and could not be neglected.…”

“…And in Ref. [15], the processes t j →g + t andg →t j + t are discussed including SUSY QCD corrections.…”

Stop reconstruction with tagged tops

“…Increasing the stop mass makes it more promising to look for decays to a bottom jet and the lightest chargino [8,9], a final state irreducible from a leptonic top decay. Finally, if the stop becomes heavier and the strong decay in a top quark and a gluino is not yet kinematically allowed, the stop can decay into a top quark and the lightest neutralino [3][4][5]. This final state has the advantage that at least hadronic top quarks we might be able to fully reconstruct, which puts us into a promising position to study angular correlations in the stop pair final state.…”

“…At the Tevatron, low-mass stop searches look for loop-induced stop decays [3][4][5] to charm quarks and the lightest neutralino [6,7]. Increasing the stop mass makes it more promising to look for decays to a bottom jet and the lightest chargino [8,9], a final state irreducible from a leptonic top decay.…”