The strong isospin-breaking correction for the gluonic penguin contribution to {epsilon}{prime}/{epsilon} at next-to-leading order in the chiral expansion
The strong isospin-breaking correction {Omega}{sub st}, which appears in estimates of the standard model value for the direct CP-violating ratio {epsilon}{prime}/{epsilon}, is evaluated to next-to-leading order (NLO) in the chiral expansion using chiral perturbation theory. The relevant linear combinations of the unknown NLO CP-odd weak low-energy constants (LEC's) which, in combination with one-loop and strong LEC contributions, are required for a complete determination at this order, are estimated using two different models. It is found that, to NLO, {Omega}{sub st}=0.08{+-}0.05, significantly reduced from the ''standard'' value, 0.25{+-}0.08, employed in recent analyses. The potentially significant numerical impact of this decrease on standard model predictions for {epsilon}{prime}/{epsilon}, associated with the decreased cancellation between gluonic penguin and electroweak penguin contributions, is also discussed.
- Sponsoring Organization:
- (US)
- OSTI ID:
- 40204974
- Journal Information:
- Physical Review D, Vol. 63, Issue 1; Other Information: DOI: 10.1103/PhysRevD.63.014008; Othernumber: PRVDAQ000063000001014008000001; 032101PRD; PBD: 1 Jan 2001; ISSN 0556-2821
- Publisher:
- The American Physical Society
- Country of Publication:
- United States
- Language:
- English
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