Rosell Escribá, IgnasiUCH. Departamento de Matemáticas, Física y Ciencias TecnológicasProducción Científica UCH 20102020-12-172020-12-172010-02-25Rosell, I. (2010). The Standard model prediction for K_e2-K_mu2 and pi_e2-pi_mu2. Proceedings of Science, vol. 086 (CD09), art. 042 (25 feb.). DOI: https://doi.org/10.22323/1.086.00421824-8039 (Electrónico)http://hdl.handle.net/10637/11773Esta comunicación se encuentra disponible en la página web de PoS en la siguiente URL: https://pos.sissa.it/086/042/pdfEsta comunicación forma parte de las comunicaciones leídas en la "6th International Workshop on Chiral Dynamics" dentro de la sesión "Tuesday, Working group 1" celebrada en Berna (Suiza) entre el 6-10 de julio de 2009.We have calculated the ratios R(P) e/m ≡ G(P → en¯e[g ])/G(P →mn¯m [g ]) (P = p ,K) in Chiral Perturbation Theory up to O(e2p4), finding R(p) e/m = (1.2352±0.0001)×10−4 and R(K) e/m = (2.477± 0.001)×10−5. This observable is helicity suppressed in the Standard Model, so that it is a sensitive probe of all Standard Model extensions that induce pseudoscalar currents and nonuniversal corrections to the lepton couplings. Ongoing experimental searches plan to reach uncertainties that are comparable to these results. At the moment R(K) e/m is in agreement with the final result by the KLOE Collaboration at DAFNE and it is at 1.4s of the preliminary result by the NA62 Experiment at CERN. New measurements of R(p) e/m are under way by the PEN Collaboration at PSI and by the PIENU Collaboration at TRIUMF.application/pdfesopen accessParticles (Nuclear physics)Partículas (Física nuclear)Cromodinámica cuántica.Campos, Teoría cuántica de.Lagrange, Funciones de.Lagrangian functions.Quantum field theory.Quantum chromodynamics.Comunicaciónhttps://doi.org/10.22323/1.086.0042https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es