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Article
Improved determination of the electroweak penguin contribution to e’/e in the chiral limit
Physics Letters B (2003)
  • Vincenzo Cirigliano
  • John Donoghue, University of Massachusetts - Amherst
  • Eugene Golowich
  • Kim Maltman
Abstract
We perform a finite energy sum rule analysis of the flavor ud two-point V-A current correlator, Delta Pi (Q^2). The analysis, which is performed using both the ALEPH and OPAL databases for the V-A spectral function, Delta rho, allows us to extract the dimension six V-A OPE coefficient, a_6, which is related to the matrix element of the electroweak penguin operator, Q_8, by chiral symmetry. The result for a_6 leads directly to the improved (chiral limit) determination epsilon'/epsilon = (- 15.0 +- 2.7) 10^{-4}. Determination of higher dimension OPE contributions also allows us to perform an independent test using a low-scale constrained dispersive analysis, which provides a highly nontrivial consistency check of the results.
Disciplines
Publication Date
2003
Publisher Statement
This is the pre-published version harvested from arXiv. The published version is located at http://arxiv.org/abs/hep-ph/0211420
Citation Information
Vincenzo Cirigliano, John Donoghue, Eugene Golowich and Kim Maltman. "Improved determination of the electroweak penguin contribution to e’/e in the chiral limit" Physics Letters B Vol. 555 (2003)
Available at: http://works.bepress.com/john_donoghue/138/