B-L Cosmic strings and Baryogenesis
| dc.creator | Bhattacharjee, Pijushpani | |
| dc.creator | Sahu, Narendra | |
| dc.creator | Yajnik, U. A. | |
| dc.date | 2004-06-04 | |
| dc.date | 2004-11-02 | |
| dc.date.accessioned | 2026-07-07T03:52:37Z | |
| dc.date.available | 2026-07-07T03:52:37Z | |
| dc.description | Cosmic strings arising from breaking of the $U(1)_{B-L}$ gauge symmetry that occurs in a wide variety of unified models can carry zero modes of heavy Majorana neutrinos. Decaying and/or repeatedly self-interacting closed loops of these ``$B-L$'' cosmic strings can be a non-thermal source of heavy right-handed Majorana neutrinos whose decay can contribute to the observed baryon asymmetry of the Universe (BAU) via the leptogenesis route. The $B-L$ cosmic strings are expected in GUT models such as SO(10), where they can be formed at an intermediate stage of symmetry breaking well below the GUT scale $\sim 10^{16}$ GeV; such light strings are not excluded by the CMB anisotropy data and may well exist. We estimate the contribution of $B-L$ cosmic string loops to the baryon-to-photon ratio of the Universe in the light of current knowledge on neutrino masses and mixings implied by atmospheric and solar neutrino measurements. We find that $B-L$ cosmic string loops can contribute significantly to the BAU for $U(1)_{B-L}$ symmetry breaking scale $η_{B-L}\gsim 1.7\times 10^{11}\gev$. At the same time, in order for the contribution of decaying $B-L$ cosmic string loops not to exceed the observed baryon-to-photon ratio inferred from the recent WMAP results, the lightest heavy right-handed Majorana neutrino mass $M_1$ must satisfy the constraint $M_1 \leq 2.4 \times 10^{12}(η_{B-L}/10^{13}\gev)^{1/2}\gev$. This may have interesting implications for the associated Yukawa couplings in the heavy neutrino sector and consequently for the light neutrino masses generated through see-saw mechanism. | |
| dc.description | match with the published version | |
| dc.identifier | https://arxiv.org/abs/hep-ph/0406054 | |
| dc.identifier | http://arxiv.org/abs/hep-ph/0406054 | |
| dc.identifier | Phys.Rev. D70 (2004) 083534 | |
| dc.identifier | doi:10.1103/PhysRevD.70.083534 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/43531 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.subject | Astrophysics | |
| dc.title | B-L Cosmic strings and Baryogenesis | |
| dc.type | text |