Kl4 - DECAYS BEYOND ONE LOOP
نویسندگان
چکیده
The matrix elements for K → ππlν decays are described by four form factors F,G,H and R. We complete previous calculations by evaluating R at next-to-leading order in the low-energy expansion. We then estimate higher order contributions using dispersion relations and determine the low-energy constants L1, L2 and L3 from data on Ke4 decays and on elastic pion scattering. Finally, we present predictions for the slope of the form factor G and for total decay rates. ♯ Work supported in part by Schweizerischer Nationalfonds/ Bundesamt für Bildung und Wissenschaft (BBW)/ EEC Human Capital and Mobility Program/ Fondazione ”Angelo della Riccia”/ INFN. a) NORDITA, Blegdamsvej 17, DK-2100 Copenhagen, Denmark. b) Universität Bern, Sidlerstrasse 5, CH−3012 Bern, Switzerland. c) Dipartimento di Fisica, Università di Roma II ”Tor Vergata”, Via della Ricerca Scientifica 1, I-00173 Roma, Italy.
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