CP violation in three-body chargino decays

MAKIKO NAGASHIMA; KEN KIERS; ALEJANDRO SZYNKMAN; DAVID LONDON; JENNA HANCHEY; KEVIN LITTLE

PHYSICAL REVIEW D

AMER PHYSICAL SOC

Año: 2009 vol. 80 p. 1 - 10

1550-7998

CP violation in supersymmetry can give rise to rate asymmetries in the decays of supersymmetric particles. In this work we compute the rate asymmetries for the three-body chargino decays χ˜2±→χ˜1±HH, χ˜2±→χ˜1±ZZ, χ˜2±→χ˜1±W+W- and χ˜2±→χ˜1±ZH. Each of the decays contains contributions mediated by neutral Higgs bosons that can possibly go on shell. Such contributions receive a resonant enhancement; furthermore, the strong phases required for the CP asymmetries come from the widths of the exchanged Higgs bosons. Our results indicate that the rate asymmetries can be relatively large in some cases, while still respecting a number of important low-energy bounds such as those coming from B meson observables and electric dipole moments. For the parameters that we consider, rate asymmetries of order 10% are possible in some cases.