Isospin-violating contributions to ∈′/∈

• DOI: 10.1007/jhep02(2020)032
• Publication Date: 2020-02-13T06:41:16Z
• Authors: V. Cirigliano; H. Gisbert; A. Pich; A. Rodríguez-Sánchez
• Keywords: Ignorance

A bstract The known isospin-breaking contributions to the K → ππ amplitudes are reanalyzed, taking into account our current understanding of quark masses and relevant non-perturbative inputs. We present a complete numerical reappraisal direct CP-violating ratio ∈ ′ /∈, where these corrections play quite significant role. obtain Standard Model prediction Re (∈ /∈) = (14 ± 5) · 10 − 4 , which is in very good agreement with measured ratio. uncertainty, has been estimated conservatively, dominated by ignorance about 1 /N C -suppressed some chiral-perturbation-theory low-energy constants.