On small Dirac neutrino masses in string theory
We study how tiny Dirac neutrino masses consistent with experimental constraints can arise in string theory SM-like vacua. We use as a laboratory 4d N = 1 type IIA Calabi-Yau orientifold compactifications, and in particular recent results on Yukawa couplings at infinite field-space distance. In this...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:dnet:digitalcsic_::6833500822102127af3defc96def4055 |
| Acceso en línea: | http://hdl.handle.net/10261/429163 https://www.scopus.com/pages/publications/85217545542?origin=resultslist |
| Access Level: | acceso abierto |
| Palabra clave: | D-Branes Large Extra Dimensions String and Brane Phenomenology Theories of Flavour |
| Sumario: | We study how tiny Dirac neutrino masses consistent with experimental constraints can arise in string theory SM-like vacua. We use as a laboratory 4d N = 1 type IIA Calabi-Yau orientifold compactifications, and in particular recent results on Yukawa couplings at infinite field-space distance. In this regime we find Dirac neutrino masses of the form mν ≃ gν⟨H⟩, with gν the gauge coupling of the massive U(1) under which the right-handed neutrinos νR are charged, and which should be in the range gν ≃ 10−14 − 10−12 to reproduce neutrino data. The neutrino mass suppression occurs because the right-handed neutrino kinetic term behaves as Kνν ≃ 1/gν2. At the same time a tower of νR-like states appears with characteristic scale m0 ≃ gν2MP ≃ 0.1 − 500 eV, in agreement with Swampland expectations. Two large hidden dimensions only felt by the νR sector arise at the same scale, while the string scale is around Ms ≃ gνMP ≃ 10 − 700 TeV. Some phenomenological implications and model building challenges are described. We also describe the difficulties in obtaining appropriate tiny neutrino Yukawas in the cases of a single or more than two large dimensions. Thus the case with two large dimensions seems to be quite unique. © The Author(s) 2025. |
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