K->pipie+e- decays and chiral low-energy constants

dc.creatorPichl, Hannes
dc.date2000-10-25
dc.date2001-03-21
dc.date.accessioned2026-07-07T12:26:05Z
dc.date.available2026-07-07T12:26:05Z
dc.descriptionThe branching ratios of the measured decay $K_L\toπ^+π^-e^+e^-$ and of the still unmeasured decay $K^+\toπ^+π^0e^+e^-$ are calculated to next-to-leading order in Chiral Perturbation Theory (CHPT). Recent experimental results are used to determine two possible values of the combination $(N^r_{16}-N_{17})$ of weak low-energy couplings (LECs) from the $\mathcal{O}(p^4)$ chiral Lagrangian. The obtained values are compared to the predictions of theoretical approaches to weak counterterm couplings to distinguish between the two values. Using the favoured value of the combination $(N^r_{16}-N_{17})$ and taking into account additional assumptions suggested by the considered models, one obtains the branching ratio of the second decay as a function of the unknown combination $(N^r_{14}+2N^r_{15})$ of weak low-energy couplings. Finally, using values of the individual LECs derived from a particular model, one predicts the branching ratio of the $K^+$ decay.
dc.description38 pages, 6 figures. Slightly enlarged version, references added, results unchanged. Accepted for publication in Eur.Phys.J.C
dc.identifierhttps://arxiv.org/abs/hep-ph/0010284
dc.identifierhttp://arxiv.org/abs/hep-ph/0010284
dc.identifierEur.Phys.J.C20:371-388,2001
dc.identifierdoi:10.1007/s100520100652
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/214772
dc.subjectHigh Energy Physics - Phenomenology
dc.titleK->pipie+e- decays and chiral low-energy constants
dc.typetext

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