Gluon dipole penguin contributions to ǫ′/ǫ and CP violation in Hyperon decays in the Standard Model

We consider the gluon dipole penguin operator contributions to ǫ′/ǫ and CP violation in hyperon decays. It has been proposed by Bertolini et al. that the contribution to ǫ′/ǫ may be significant. We show that there is a cancellation in the leading order contribution and this contribution is actually suppressed by a factor of order O(mπ,m 2 K)/Λ 2. We find that the same operator also contributes to CP violation in hyperon decays where it is not suppressed. The gluon dipole penguin operator can enhance CP violation in hyperon decays by as much as 25%. Typeset using REVTEX 1 In this paper we study the gluon dipole penguin operator s̄σtGμν(1−γ5)d contributions to ǫ′/ǫ and CP violation in hyperon decays in the Standard Model (SM). The effective ∆S = 1 Hamiltonian at leading order can be parametrized as Heff = GF √ 2 VudV ∗ us ∑