New constraint on squark flavor mixing from 199Hg electric dipole moment

Abstract

A new constraint is obtained on the CP-violating flavor mixing between the left-handed top scalar quark (t̃L) and charm scalar quark (c̃L), by considering a chargino loop contribution to chromo-electric dipole moment of strange quark, which is limited by the electric dipole moment of the 199Hg atom. It is found that the flavor mixing should be suppressed to the level of O(0.1) for the CP phase of order unity, when tanβ is relatively large and sparticle masses lie in a few hundred GeV range. Although it is much stronger than the known constraint from the chargino loop contribution to b→sγ, the moderate constraint we obtain here is argued to leave room for sizable supersymmetric contribution to the CP asymmetry in Bd0→φKs.