Why three generations?
We discuss an anthropic explanation of why there exist three generations of fermions. If one assumes that the right-handed neutrino sector is responsible for both the matter–antimatter asymmetry and the dark matter, then anthropic selection favors three or more families of fermions. For successful l...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2016-07-01
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| Series: | Physics Letters B |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0370269316301721 |
| _version_ | 1811201229842284544 |
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| author | Masahiro Ibe Alexander Kusenko Tsutomu T. Yanagida |
| author_facet | Masahiro Ibe Alexander Kusenko Tsutomu T. Yanagida |
| author_sort | Masahiro Ibe |
| collection | DOAJ |
| description | We discuss an anthropic explanation of why there exist three generations of fermions. If one assumes that the right-handed neutrino sector is responsible for both the matter–antimatter asymmetry and the dark matter, then anthropic selection favors three or more families of fermions. For successful leptogenesis, at least two right-handed neutrinos are needed, while the third right-handed neutrino is invoked to play the role of dark matter. The number of the right-handed neutrinos is tied to the number of generations by the anomaly constraints of the U(1)B−L gauge symmetry. Combining anthropic arguments with observational constraints, we obtain predictions for the X-ray observations, as well as for neutrinoless double-beta decay. |
| first_indexed | 2024-04-12T02:18:37Z |
| format | Article |
| id | doaj.art-14c605b8359244879ec94a24e1edf6e2 |
| institution | Directory Open Access Journal |
| issn | 0370-2693 1873-2445 |
| language | English |
| last_indexed | 2024-04-12T02:18:37Z |
| publishDate | 2016-07-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Physics Letters B |
| spelling | doaj.art-14c605b8359244879ec94a24e1edf6e22022-12-22T03:52:12ZengElsevierPhysics Letters B0370-26931873-24452016-07-01758C36536910.1016/j.physletb.2016.05.025Why three generations?Masahiro Ibe0Alexander Kusenko1Tsutomu T. Yanagida2ICRR, University of Tokyo, Kashiwa, 277-8582, JapanKavli IPMU, University of Tokyo (WPI), Kashiwa, 277-8568, JapanKavli IPMU, University of Tokyo (WPI), Kashiwa, 277-8568, JapanWe discuss an anthropic explanation of why there exist three generations of fermions. If one assumes that the right-handed neutrino sector is responsible for both the matter–antimatter asymmetry and the dark matter, then anthropic selection favors three or more families of fermions. For successful leptogenesis, at least two right-handed neutrinos are needed, while the third right-handed neutrino is invoked to play the role of dark matter. The number of the right-handed neutrinos is tied to the number of generations by the anomaly constraints of the U(1)B−L gauge symmetry. Combining anthropic arguments with observational constraints, we obtain predictions for the X-ray observations, as well as for neutrinoless double-beta decay.http://www.sciencedirect.com/science/article/pii/S0370269316301721 |
| spellingShingle | Masahiro Ibe Alexander Kusenko Tsutomu T. Yanagida Why three generations? Physics Letters B |
| title | Why three generations? |
| title_full | Why three generations? |
| title_fullStr | Why three generations? |
| title_full_unstemmed | Why three generations? |
| title_short | Why three generations? |
| title_sort | why three generations |
| url | http://www.sciencedirect.com/science/article/pii/S0370269316301721 |
| work_keys_str_mv | AT masahiroibe whythreegenerations AT alexanderkusenko whythreegenerations AT tsutomutyanagida whythreegenerations |