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) |
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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, 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: |
05 Dec 2022 14:58 |
BORIS DOI: |
10.7892/boris.86289 |
URI: |
https://boris.unibe.ch/id/eprint/86289 |
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