A dispersive treatment of K ℓ 4 decays

Colangelo, Gilberto; Passemar, Emilie; Stoffer, Peter (2015). A dispersive treatment of K ℓ 4 decays. European physical journal. C - particles and fields, 75(4) EDP Sciences 10.1140/epjc/s10052-015-3357-1

[img]
Preview
Text
art%3A10.1140%2Fepjc%2Fs10052-015-3357-1.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (3MB) | Preview

Kℓ4 decays have several features of interest: they allow an accurate measurement of ππ-scattering lengths; they provide the best source for the determination of some low-energy constants of χPT; one form factor is directly related to the chiral anomaly, which can be measured here. We present a dispersive treatment of Kℓ4 decays that 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. The matching to χPT at NLO and NNLO enables us to determine the LECs Lr1, Lr2 and Lr3. With recently published data from NA48/2, the LEC Lr9 can be determined as well. In contrast to a pure chiral treatment, the dispersion relation describes the observed curvature of one of the form factors, which we understand as a rescattering effect beyond NNLO.

Item Type:

Journal Article (Original Article)

Division/Institute:

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

UniBE Contributor:

Colangelo, Gilberto; Passemar, Emilie and Stoffer, Peter

Subjects:

500 Science > 530 Physics

ISSN:

1434-6044

Publisher:

EDP Sciences

Language:

English

Submitter:

Esther Fiechter

Date Deposited:

31 Aug 2015 17:11

Last Modified:

31 Aug 2015 17:11

Publisher DOI:

10.1140/epjc/s10052-015-3357-1

BORIS DOI:

10.7892/boris.71428

URI:

https://boris.unibe.ch/id/eprint/71428

Actions (login required)

Edit item Edit item
Provide Feedback