New Dipole Penguin Contribution to K --> pi pi decays

Eeg, Jan O.; Kumericki, Kresimir; Picek, Ivica

New Dipole Penguin Contribution to K --> pi pi decays

Authors

Eeg, Jan O.

Kumericki, Kresimir

Picek, Ivica

Description

We point out that the standard chromomagnetic penguin dipole operator has a counterpart corresponding to off-shell momenta for external quarks. By employing the chiral quark model, we show that this new dipole penguin operator has the same bosonisation as the standard Q_6 operator. Accordingly, this new operator enlarges by ~ 5 % the referent Q_6 contribution, which gives the dominant contribution to the CP-violating ratio epsilon'/epsilon and also gives an important contribution to the Delta I = 1/2 amplitude.
17 pages, 1 PS figure, LaTeX, corresponds to published version