Decrypting SO(10)-inspired leptogenesis
Encouraged by the recent results from neutrino oscillation experiments, we perform an analytical study of SO(10)-inspired models and leptogenesis with hierarchical right-handed (RH) neutrino spectrum. Under the approximation of negligible misalignment between the neutrino Yukawa basis and the charge...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2015-04-01
|
| Series: | Nuclear Physics B |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0550321315000516 |
| _version_ | 1819267397076385792 |
|---|---|
| author | Pasquale Di Bari Luca Marzola Michele Re Fiorentin |
| author_facet | Pasquale Di Bari Luca Marzola Michele Re Fiorentin |
| author_sort | Pasquale Di Bari |
| collection | DOAJ |
| description | Encouraged by the recent results from neutrino oscillation experiments, we perform an analytical study of SO(10)-inspired models and leptogenesis with hierarchical right-handed (RH) neutrino spectrum. Under the approximation of negligible misalignment between the neutrino Yukawa basis and the charged lepton basis, we find an analytical expression for the final asymmetry directly in terms of the low energy neutrino parameters that fully reproduces previous numerical results. This expression also shows that it is possible to identify an effective leptogenesis phase for these models. When we also impose the wash-out of a large pre-existing asymmetry NB−Lp,i, the strong thermal (ST) condition, we derive analytically all those constraints on the low energy neutrino parameters that characterise the ST-SO(10)-inspired leptogenesis solution, confirming previous numerical results. In particular we show why, though neutrino masses have to be necessarily normally ordered, the solution implies an analytical lower bound on the effective neutrino-less double beta decay neutrino mass, mee≳8 meV, for NB−Lp,i=10−3, testable with next generation experiments. This, in combination with an upper bound on the atmospheric mixing angle, necessarily in the first octant, forces the lightest neutrino mass within a narrow range m1≃(10–30) meV (corresponding to ∑imi≃(75–125) meV). We also show why the solution could correctly predict a non-vanishing reactor neutrino mixing angle and requires the Dirac phase to be in the fourth quadrant, implying sinδ (and JCP) negative as hinted by current global analyses. Many of the analytical results presented (expressions for the orthogonal matrix, RH neutrino mixing matrix, masses and phases) can have applications beyond leptogenesis. |
| first_indexed | 2024-12-23T21:16:31Z |
| format | Article |
| id | doaj.art-10c07302db8440fdb6d89be9bae8ec34 |
| institution | Directory Open Access Journal |
| issn | 0550-3213 |
| language | English |
| last_indexed | 2024-12-23T21:16:31Z |
| publishDate | 2015-04-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Nuclear Physics B |
| spelling | doaj.art-10c07302db8440fdb6d89be9bae8ec342022-12-21T17:30:53ZengElsevierNuclear Physics B0550-32132015-04-01893122157Decrypting SO(10)-inspired leptogenesisPasquale Di Bari0Luca Marzola1Michele Re Fiorentin2Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ, UK; Corresponding authors.Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu, Estonia; Corresponding authors.Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ, UK; Corresponding authors.Encouraged by the recent results from neutrino oscillation experiments, we perform an analytical study of SO(10)-inspired models and leptogenesis with hierarchical right-handed (RH) neutrino spectrum. Under the approximation of negligible misalignment between the neutrino Yukawa basis and the charged lepton basis, we find an analytical expression for the final asymmetry directly in terms of the low energy neutrino parameters that fully reproduces previous numerical results. This expression also shows that it is possible to identify an effective leptogenesis phase for these models. When we also impose the wash-out of a large pre-existing asymmetry NB−Lp,i, the strong thermal (ST) condition, we derive analytically all those constraints on the low energy neutrino parameters that characterise the ST-SO(10)-inspired leptogenesis solution, confirming previous numerical results. In particular we show why, though neutrino masses have to be necessarily normally ordered, the solution implies an analytical lower bound on the effective neutrino-less double beta decay neutrino mass, mee≳8 meV, for NB−Lp,i=10−3, testable with next generation experiments. This, in combination with an upper bound on the atmospheric mixing angle, necessarily in the first octant, forces the lightest neutrino mass within a narrow range m1≃(10–30) meV (corresponding to ∑imi≃(75–125) meV). We also show why the solution could correctly predict a non-vanishing reactor neutrino mixing angle and requires the Dirac phase to be in the fourth quadrant, implying sinδ (and JCP) negative as hinted by current global analyses. Many of the analytical results presented (expressions for the orthogonal matrix, RH neutrino mixing matrix, masses and phases) can have applications beyond leptogenesis.http://www.sciencedirect.com/science/article/pii/S0550321315000516 |
| spellingShingle | Pasquale Di Bari Luca Marzola Michele Re Fiorentin Decrypting SO(10)-inspired leptogenesis Nuclear Physics B |
| title | Decrypting SO(10)-inspired leptogenesis |
| title_full | Decrypting SO(10)-inspired leptogenesis |
| title_fullStr | Decrypting SO(10)-inspired leptogenesis |
| title_full_unstemmed | Decrypting SO(10)-inspired leptogenesis |
| title_short | Decrypting SO(10)-inspired leptogenesis |
| title_sort | decrypting so 10 inspired leptogenesis |
| url | http://www.sciencedirect.com/science/article/pii/S0550321315000516 |
| work_keys_str_mv | AT pasqualedibari decryptingso10inspiredleptogenesis AT lucamarzola decryptingso10inspiredleptogenesis AT michelerefiorentin decryptingso10inspiredleptogenesis |