$CP$ violation at one loop in the polarization-independent chargino production in ${e}^{+}{e}^{\ensuremath{-}}$ collisions

$C P$ violation at one loop in the polarization-independent chargino production in $e^{+} e^{-}$ collisions

K. Rolbiecki and J. Kalinowski

Phys. Rev. D 76, 115006 – Published 6 December 2007

Abstract

Recently Osland and Vereshagin noticed, based on sample calculations of some box diagrams, that in unpolarized $e^{+} e^{-}$ collisions $C P$ -odd effects in the nondiagonal chargino-pair production process are generated at one loop. Here we perform a full one-loop analysis of these effects and point out that in some cases the neglected vertex and self-energy contributions may play a dominant role. We also show that $C P$ asymmetries in chargino production are sensitive not only to the phase of $μ$ parameter in the chargino sector but also to the phase of stop trilinear coupling $A_{t}$ .