A dispersive treatment of Kl4 decays

Stoffer, Peter; Colangelo, Gilberto; Passemar, Emilie (2016). A dispersive treatment of Kl4 decays. PoS - proceedings of science, CD15, 067. Scuola Internazionale Superiore di Studi Avanzati SISSA

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Kl4 decays have several features of interest: they allow an accurate measurement of pp-scattering lengths; the decay is the best source for the determination of some low-energy constants of chiral perturbation theory (cPT); one form factor of the decay is connected to the chiral anomaly. We present the results of our dispersive analysis of Kl4 decays, which provides a resummation of pp- and Kp-rescattering effects. The free parameters of the dispersion relation are fitted to the data of the high-statistics experiments E865 and NA48/2. The data input is corrected for additional isospin-breaking effects, which were not taken into account in the experimental analyses. By matching to cPT at NLO and NNLO, we determine the low-energy constants Lr1, Lr2 and Lr3. In contrast to a pure chiral treatment, the dispersion relation describes the observed curvature of one of the Kl4 form factors, which we understand as an effect of rescattering beyond NNLO.

Item Type:

Conference or Workshop Item (Paper)

Division/Institute:

10 Strategic Research Centers > Albert Einstein Center for Fundamental Physics (AEC)
08 Faculty of Science > Institute of Theoretical Physics

UniBE Contributor:

Stoffer, Peter; Colangelo, Gilberto and Passemar, Emilie

Subjects:

500 Science > 530 Physics

ISSN:

1824-8039

Publisher:

Scuola Internazionale Superiore di Studi Avanzati SISSA

Language:

English

Submitter:

Esther Fiechter

Date Deposited:

31 Aug 2016 08:22

Last Modified:

31 Aug 2016 08:22

BORIS DOI:

10.7892/boris.86289

URI:

https://boris.unibe.ch/id/eprint/86289

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