TY - JOUR

T1 - Matrix elements of electroweak penguin operators in the 1/NC expansion

AU - Knecht, Marc

AU - Peris, Santiago

AU - De Rafael, Eduardo

PY - 1999/1/1

Y1 - 1999/1/1

N2 - It is shown that the K → ππ matrix elements of the four-quark operator Q7, generated by the electroweak penguin-like diagrams of the Standard Model, can be calculated to first non-trivial order in the chiral expansion and in the 1/Nc expansion. Although the resulting B factors B7(1/2) and B7(3/2) are found to depend only logarithmically on the matching scale μ, their actual numerical values turn out to be rather sensitive to the precise choice of μ in the GeV region. We compare our results to recent numerical evaluations from lattice-QCD and to other model estimates. © 1999 Elsevier Science B.V. All rights reserved.

AB - It is shown that the K → ππ matrix elements of the four-quark operator Q7, generated by the electroweak penguin-like diagrams of the Standard Model, can be calculated to first non-trivial order in the chiral expansion and in the 1/Nc expansion. Although the resulting B factors B7(1/2) and B7(3/2) are found to depend only logarithmically on the matching scale μ, their actual numerical values turn out to be rather sensitive to the precise choice of μ in the GeV region. We compare our results to recent numerical evaluations from lattice-QCD and to other model estimates. © 1999 Elsevier Science B.V. All rights reserved.

U2 - https://doi.org/10.1016/S0370-2693(99)00425-6

DO - https://doi.org/10.1016/S0370-2693(99)00425-6

M3 - Article

VL - 457

SP - 227

EP - 235

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

SN - 0370-2693

ER -