Neutrino charge radius and electromagnetic dipole moments via scalar and vector leptoquarks
Abstract The one-loop contribution of scalar and vector leptoquarks (LQs) to the electromagnetic properties (NEPs) of massive Dirac neutrinos is presented via an effective Lagrangian approach. For the contribution of gauge LQs to the effective neutrino charge radius defined in Bernabeu et al. (Phys...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2024-03-01
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| Series: | European Physical Journal C: Particles and Fields |
| Online Access: | https://doi.org/10.1140/epjc/s10052-024-12495-1 |
| _version_ | 1797273471169855488 |
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| author | A. Bolaños-Carrera M. Guiot-Lomelí G. Tavares-Velasco |
| author_facet | A. Bolaños-Carrera M. Guiot-Lomelí G. Tavares-Velasco |
| author_sort | A. Bolaños-Carrera |
| collection | DOAJ |
| description | Abstract The one-loop contribution of scalar and vector leptoquarks (LQs) to the electromagnetic properties (NEPs) of massive Dirac neutrinos is presented via an effective Lagrangian approach. For the contribution of gauge LQs to the effective neutrino charge radius defined in Bernabeu et al. (Phys Rev Lett 89:101802, 2002. https://doi.org/10.1103/PhysRevLett.89.101802 [Erratum: Phys Rev Lett 89:229902 (2002)]), we considered a Yang–Mills scenario and used the background field method for the calculation. Analytical results for nonzero neutrino mass are presented, which can be useful to obtain the NEPs of heavy neutrinos, out of which approximate expressions are obtained for light neutrinos. For the numerical analysis we concentrate on the only renormalizable scalar and vector LQ representations that do not need extra symmetries to forbid tree-level proton decay. Constraints on the parameter space consistent with current experimental data are then discussed and it is found that the scalar $${\widetilde{R}}_2$$ R ~ 2 and the vector $$U_1$$ U 1 representations could yield the largest LQ contributions to the NEPs: for LQ couplings to both left- and right handed neutrinos of the order of O(1) and a LQ mass of 1.5-2 TeV, the magnetic dipole moment (MDM) of a Dirac neutrino with a mass in the eV scale can be of the order of $$10^{-9}$$ 10 - 9 – $$10^{-10}$$ 10 - 10 $$\mu _B$$ μ B , whereas its neutrino electric dipole moment (EDM) can reach values as high as $$10^{-20}$$ 10 - 20 – $$10^{-19}$$ 10 - 19 ecm. On the other hand, the effective NCR can reach values up to $$10^{-35}$$ 10 - 35 cm $$^2$$ 2 even if LQs do not couple to right-handed neutrinos, in which case the EDM vanishes and the contribution to the MDM would be negligible. |
| first_indexed | 2024-03-07T14:44:47Z |
| format | Article |
| id | doaj.art-7cdccf071ad447518ecb3548ff945ced |
| institution | Directory Open Access Journal |
| issn | 1434-6052 |
| language | English |
| last_indexed | 2024-03-07T14:44:47Z |
| publishDate | 2024-03-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | European Physical Journal C: Particles and Fields |
| spelling | doaj.art-7cdccf071ad447518ecb3548ff945ced2024-03-05T20:03:19ZengSpringerOpenEuropean Physical Journal C: Particles and Fields1434-60522024-03-0184312410.1140/epjc/s10052-024-12495-1Neutrino charge radius and electromagnetic dipole moments via scalar and vector leptoquarksA. Bolaños-Carrera0M. Guiot-Lomelí1G. Tavares-Velasco2Tecnologico de Monterrey, School of Engineering and SciencesFacultad de Ciencias Físico-Matemáticas, Benemérita Universidad Autónoma de PueblaFacultad de Ciencias Físico-Matemáticas, Benemérita Universidad Autónoma de PueblaAbstract The one-loop contribution of scalar and vector leptoquarks (LQs) to the electromagnetic properties (NEPs) of massive Dirac neutrinos is presented via an effective Lagrangian approach. For the contribution of gauge LQs to the effective neutrino charge radius defined in Bernabeu et al. (Phys Rev Lett 89:101802, 2002. https://doi.org/10.1103/PhysRevLett.89.101802 [Erratum: Phys Rev Lett 89:229902 (2002)]), we considered a Yang–Mills scenario and used the background field method for the calculation. Analytical results for nonzero neutrino mass are presented, which can be useful to obtain the NEPs of heavy neutrinos, out of which approximate expressions are obtained for light neutrinos. For the numerical analysis we concentrate on the only renormalizable scalar and vector LQ representations that do not need extra symmetries to forbid tree-level proton decay. Constraints on the parameter space consistent with current experimental data are then discussed and it is found that the scalar $${\widetilde{R}}_2$$ R ~ 2 and the vector $$U_1$$ U 1 representations could yield the largest LQ contributions to the NEPs: for LQ couplings to both left- and right handed neutrinos of the order of O(1) and a LQ mass of 1.5-2 TeV, the magnetic dipole moment (MDM) of a Dirac neutrino with a mass in the eV scale can be of the order of $$10^{-9}$$ 10 - 9 – $$10^{-10}$$ 10 - 10 $$\mu _B$$ μ B , whereas its neutrino electric dipole moment (EDM) can reach values as high as $$10^{-20}$$ 10 - 20 – $$10^{-19}$$ 10 - 19 ecm. On the other hand, the effective NCR can reach values up to $$10^{-35}$$ 10 - 35 cm $$^2$$ 2 even if LQs do not couple to right-handed neutrinos, in which case the EDM vanishes and the contribution to the MDM would be negligible.https://doi.org/10.1140/epjc/s10052-024-12495-1 |
| spellingShingle | A. Bolaños-Carrera M. Guiot-Lomelí G. Tavares-Velasco Neutrino charge radius and electromagnetic dipole moments via scalar and vector leptoquarks European Physical Journal C: Particles and Fields |
| title | Neutrino charge radius and electromagnetic dipole moments via scalar and vector leptoquarks |
| title_full | Neutrino charge radius and electromagnetic dipole moments via scalar and vector leptoquarks |
| title_fullStr | Neutrino charge radius and electromagnetic dipole moments via scalar and vector leptoquarks |
| title_full_unstemmed | Neutrino charge radius and electromagnetic dipole moments via scalar and vector leptoquarks |
| title_short | Neutrino charge radius and electromagnetic dipole moments via scalar and vector leptoquarks |
| title_sort | neutrino charge radius and electromagnetic dipole moments via scalar and vector leptoquarks |
| url | https://doi.org/10.1140/epjc/s10052-024-12495-1 |
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