One-loop effects on MSSM parameter determination via chargino production at the LC

Abstract

At a future linear collider very precise measurements, typically with errors of < 1%, are expected to be achievable. Such an accuracy gives sensitivity to the quantum corrections, which therefore must be incorporated in theoretical calculations in order to determine the underlying new physics parameters from prospective linear collider measurements. In the context of the chargino-neutralino sector of the minimal supersymmetric standard model, this involves fitting one-loop predictions to prospective measurements of the cross sections, forward-backward asymmetries and of the accessible chargino and neutralino masses. Taking recent results from LHC SUSY and Higgs searches into account we consider three benchmark scenarios, each with characteristic features. Our analysis shows how an accurate determination of the desired parameters is possible, providing in addition access to the stop masses and mixing angle. * aoife.bharucha@desy.de †

Neutralinos betray their singlino nature at the ILC

“…One should note that these are fundamental parameters without any assumption on the SUSY breaking scheme. Precise determination of these parameters is possible at a linear collider [11][12][13][14]22], provided thatχ 0 1 ,χ 0 2 andχ ± 1 can be produced at the LC and their masses as well as the polarized cross sections σ(e + e − →χ 0 1χ 0 2 ), σ(e + e − →χ + 1χ − 1 ) are measured. An accurate and rather model-independent determination of M 1 , M 2 , µ, tan β is performed by a χ 2 -minimisation that selects the parameters fitting the experimental results.…”