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Title: Direct CP violation in K r arrow 3. pi. decay

Journal Article · · Physical Review, D (Particles Fields); (USA)
 [1]
  1. Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (US) Institute of Physics, Academia Sinica, Taipei, Taiwan 11529, Republic of China

In light of the fact that the presence of the {ital Z}{sup 0} penguin diagram suppresses strongly {epsilon}{sub 2{pi}}{sup {prime}}/{epsilon} in {ital K}{sup 0}{r arrow}2{pi} decay for large values of {ital m}{sub {ital t}}, we reanalyze the direct decay-amplitude {ital CP} violation in {ital K}{sup 0}{r arrow}3{pi} decays in the Kobayashi-Maskawa model. The effects due to electroweak penguins, isospin breaking, and higher-order weak chiral Lagrangians are studied in the large-{ital N}{sub {ital c}} approach. We find that the Li-Wolfenstein relation between {epsilon}{sub 3{pi}}{sup {prime}} and {epsilon}{sub 2{pi}}{sup {prime}} is modified dramatically: the former receives very large contributions from the higher-derivative chiral terms and sizable contributions from the isospin-breaking correction due to {pi}{sup 0}-{eta}-{eta}{prime} mixing and {eta}, {eta}{prime}{r arrow}3{pi} transitions. When the top quark becomes very heavy, effects of the electroweak penguin terms are enhanced. Unlike {epsilon}{sub 2{pi}}{sup {prime}}/{epsilon}, which decreases as {ital m}{sub {ital t}} increases, the {ital CP}-violating parameter {epsilon}{sub 3{pi}}{sup {prime}}/{epsilon} is of order 10{sup {minus}2} and increases with the heavy top-quark mass.

OSTI ID:
6143330
Journal Information:
Physical Review, D (Particles Fields); (USA), Vol. 43:5; ISSN 0556-2821
Country of Publication:
United States
Language:
English