Weak triplet models of neutrino magnetic moments

Fajfer, Svjetlana (author), Saad, Shaikh (author)

Experimental limits on neutrino magnetic moments remain several orders of magnitude above the predictions of the Standard Model; therefore, any future detection would provide unambiguous evidence for new physics. In models with Dirac neutrinos, however, mechanisms that enhance the magnetic moment typically generate excessively large neutrino masses. Recently, it has been argued that in frameworks where neutrinos mix with weak-triplet Dirac fermions, the magnetic moment can be decoupled from the neutrino mass. In this work, we revisit this possibility and show that sizable enhancements remain highly nontrivial to realize naturally. We demonstrate that, although the minimal realization allows the magnetic moment to be decoupled from the neutrino mass, obtaining an observable enhancement requires a delicate adjustment of the model parameters. Moreover, in extended scenarios, the decoupling no longer persists: the magnetic moment and neutrino mass become intrinsically linked, such that attempts to enhance the former inevitably induce large contributions to the latter.

• Language: English
• Keywords: physics of elementary particles
• 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: 11 str.
• Numbering: Vol. 86, art. no. 1150
• PID: 20.500.12556/RUL-189477
• UDC: 539.120
• ISSN on article: 1434-6052
• DOI: 10.1140/epjc/s10052-026-16456-8
• COBISS.SI-ID: 294111747
• Publication date in RUL: 07.10.2026

Record is a part of a journal

• Title: European physical journal : Particles and fields
• Shortened title: Eur. phys. j., C Part. fields
• Publisher: Springer
• ISSN: 1434-6052
• COBISS.SI-ID: 516110361

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

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: N1-0321
• Name: Obarvani skalari v fiziki onkraj standardnega modela

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P1-0035
• Name: Teorija jedra, osnovnih delcev in polj