Probing the neutrino mass through semileptonic meson decays

Bečirević, Damir (author), Chevallier, Claire (author), Fajfer, Svjetlana (author), Košnik, Nejc (author), Pavičić, Lovre (author)

We argue that a detailed analysis of semileptonic decays can test the possibility of a massive neutrino. The key observable, related to the forward–backward asymmetry, is exactly zero for a massless neutrino but becomes nonzero if the neutral lepton is heavy and interacts with Standard Model fields via lefthanded operators. For righthanded interactions, this quantity differs significantly from zero even for a massless righthanded neutrino. We demonstrate this explicitly using the example of a pseudoscalar meson decaying into another pseudoscalar meson. A similar discussion applies to decays into a vector meson, with an additional subtlety addressed in this work.

• Language: English
• Keywords: physics of elementary particles, neutrinos
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: Str. 035005-1-035005-12
• Numbering: Vol. 114, iss. 3
• PID: 20.500.12556/RUL-185469
• UDC: 539.120
• ISSN on article: 2470-0010
• DOI: 10.1103/793f-29kk
• COBISS.SI-ID: 287107075
• Publication date in RUL: 06.08.2026

Record is a part of a journal

• Title: Physical review
• Shortened title: Phys. rev., D
• Publisher: American Physical Society
• ISSN: 2470-0010
• COBISS.SI-ID: 29757223

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: fizika osnovnih delcev, nevtrini