arXiv:hep-ph/9912398·v2·High Energy Physics — Phenomenology
Low Energy Constants from Kl4 Form-Factors
G. Amorós (Lund U. & Helsinki U.)🇫🇮 · J. Bijnens🇸🇪 · P. Talavera (Lund U.)🇸🇪
Abstract
We have calculated the form-factors F and G in K ---> pi pi e nu decays (Kl4) to two-loop order in Chiral Perturbation Theory (ChPT). Combining this together with earlier two-loop calculations an updated set of values for the L's, the ChPT constants at p^4, is obtained. We discuss the uncertainties in the determination and the changes compared to previous estimates.
Comments: 6 pages, uses axodraw.sty, 2 figures, bug in program corrected, new numerical results