Signatures from an extra-dimensional seesaw model
2010 (English)In: Physical Review D, ISSN 1550-7998, Vol. 82, no 4, 045023- p.Article in journal (Refereed) Published
We study the generation of small neutrino masses in an extra-dimensional model, where singlet fermions are allowed to propagate in the extra dimension, while the standard model particles are confined to a brane. Motivated by the fact that extra-dimensional models are nonrenormalizable, we truncate the Kaluza-Klein towers at a maximal Kaluza-Klein number. This truncation, together with the structure of the bulk Majorana mass term, motivated by the Sherk-Schwarz mechanism, implies that the Kaluza-Klein modes of the singlet fermions pair to form Dirac fermions, except for a number of unpaired Majorana fermions at the top of each tower. These heavy Majorana fermions are the only sources of lepton number breaking in the model, and similarly to the type-I seesaw mechanism, they naturally generate small masses for the left-handed neutrinos. The lower Kaluza-Klein modes mix with the light neutrinos, and the mixing effects are not suppressed with respect to the light-neutrino masses. Compared to conventional fermionic seesaw models, such mixing can be more significant. We study the signals of this model at the Large Hadron Collider, and find that the current low-energy bounds on the nonunitarity of the leptonic mixing matrix are strong enough to exclude an observation.
Place, publisher, year, edition, pages
The American Physical Society , 2010. Vol. 82, no 4, 045023- p.
NEUTRINO OSCILLATIONS, PHENOMENOLOGICAL IMPLICATIONS, CP-VIOLATION, MASSES, UNIVERSE, MIXINGS, PHYSICS, LHC
IdentifiersURN: urn:nbn:se:kth:diva-26840DOI: 10.1103/PhysRevD.82.045023ISI: 000281070800010OAI: oai:DiVA.org:kth-26840DiVA: diva2:374598
FunderEU, FP7, Seventh Framework ProgrammeSwedish Research Council, 621-2008-4210
Denna artikel är en granskad och publicerad version av manuskriptet "Non-unitary neurtino mixing from an extra-dimensional seesaw model" som hör till avhandlingen "Astrophysical and Collider Signatures of Extra Dimensions".
This article is a peer-reviewed and published version of the manuscript "Non-unitary neurtino mixing from an extra-dimensional seesaw model" which is a part of the doctoral dissertation "Astrophysical and Collider Signatures of Extra Dimensions".2011-06-172010-11-292012-04-27Bibliographically approved