Eur. Phys. J. C (2006) 45: 451-457
https://doi.org/10.1140/epjc/s2005-02442-3

Theoretical Physics

ΔS = 0 effective weak chiral Lagrangianfrom the instanton vacuum

¹ Department of Physics and Nuclear Physics and Radiation Technology Institute (NuRI), Pusan National University, 609-735, Busan, Republic of Korea
² Departament de Fisica Teórica, Universitat de Valéncia, 46100, Burjassot (Valéncia), Spain
³ Seoul National University, School of Physics, 151-742, Seoul, Republic of Korea
⁴ Institute of Basic Science, Sungkyunkwan University, 440-746, Suwon, Republic of Korea

^* e-mail: hjlee@www.apctp.org

Received: 13 February 2005
Revised: 9 August 2005
Published online: 9 December 2005

Abstract

We investigate the ΔS = 0 effective chiral Lagrangian from the instanton vacuum. Based on the ΔS = 0 effective weak Hamiltonian from the operator product expansion and renormalization group equations, we derive the strangeness-conserving effective weak chiral Lagrangian from the instanton vacuum to order and the next-to-leading order in the 1/N _c expansion at the quark level. We find that the quark condensate and a dynamical term which arise from the QCD and electroweak penguin operators appear in the next-to-leading order in the 1/N _c expansion for the ΔS = 0 effective weak chiral Lagrangian, while they are in the leading order terms in the ΔS = 1 case. Three different types of form factors are employed and we find that the dependence on the different choices of the form factor is rather insensitive. The low-energy constants of the Gasser-Leutwyler type are determined and discussed in the chiral limit.