Lellouch-Lüscher factor for the K → 3π decays

Autor: Jin-Yi Pang, Rishabh Bubna, Fabian Müller, Akaki Rusetsky, Jia-Jun Wu
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Journal of High Energy Physics, Vol 2024, Iss 5, Pp 1-41 (2024)
Druh dokumentu: article
ISSN: 1029-8479
DOI: 10.1007/JHEP05(2024)269
Popis: Abstract We derive an explicit expression for the Lellouch-Lüscher (LL) factor in the K → 3π decays at leading order (without derivative couplings). Several important technical details are addressed, like a proper decomposition into the isospin amplitudes, the choice of a minimal set of effective couplings and the renormalization, as well as the algorithm for the solution of the pertinent Faddeev equations in the infinite volume which is based on the contour deformation method. Most importantly, our numerical results demonstrate that the three-body force contributes very little to the LL factor. This result paves the way for the study of the K → 3π decays on the lattice.
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