A dispersive treatment of K_ι4 decays

Journal Article · Sun Jan 01 00:00:00 EST 2017 · Journal of Physics. Conference Series

DOI:https://doi.org/10.1088/1742-6596/800/1/012026· OSTI ID:1362016

Stoffer, Peter ^[1]; Colangelo, Gilberto ^[2]; Passemar, Emilie ^[3]

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1. Univ. of Bonn, Bonn (Germany)
2. Univ. of Bern, Bern (Switzerland)
3. Indiana Univ., Bloomington, IN (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

K_ι4 decays have several features of interest: they allow an accurate measurement of ππ-scattering lengths; the decay is the best source for the determination of some low-energy constants of chiral perturbation theory (χPT); one form factor of the decay is connected to the chiral anomaly. Here, we present the results of our dispersive analysis of K_ι4 decays, which provides a resummation of ππ- and Kπ-rescattering effects. The free parameters of the dispersion relation are fitted to the data of the high-statistics experiments E865 and NA48/2. By matching to χPT at NLO and NNLO, we determine the low-energy constants and L^r₁, L^r₂, and L^r₃. In contrast to a pure chiral treatment, the dispersion relation describes the observed curvature of one of the K_ι4 form factors, which we understand as an effect of rescattering beyond NNLO.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: AC05-06OR23177
• OSTI ID: 1362016
• Report Number(s): JLAB-THY-17-2489; DOE/OR/23177-4162
• Journal Information: Journal of Physics. Conference Series, Vol. 800; Conference: International Conference on Kaon Physics (KAON 2016), Birmingham (United Kingdom), 14-17 Sep 2016; ISSN 1742-6588
• Publisher: IOP Publishing
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS