Signatures from an extra-dimensional seesaw model

Journal Article · Sun Aug 15 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.82.045023· OSTI ID:21421010

Blennow, Mattias ^[1]; Melbeus, Henrik; Ohlsson, Tommy; He, Zhang ^[2]

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1. Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, 80805 Muenchen (Germany)
2. Department of Theoretical Physics, School of Engineering Sciences, Royal Institute of Technology (KTH)-AlbaNova University Center, Roslagstullsbacken 21, 106 91 Stockholm (Sweden)

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.

• OSTI ID: 21421010
• Journal Information: Physical Review. D, Particles Fields, Vol. 82, Issue 4; Other Information: DOI: 10.1103/PhysRevD.82.045023; (c) 2010 American Institute of Physics; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BRANES
CERN LHC
FERMIONS
KALUZA-KLEIN THEORY
LEPTON NUMBER
MAJORANA THEORY
MASS
MIXING
NEUTRINOS
PARTICLES
STANDARD MODEL
ACCELERATORS
CYCLIC ACCELERATORS
ELEMENTARY PARTICLES
FIELD THEORIES
GRAND UNIFIED THEORY
LEPTONS
MASSLESS PARTICLES
MATHEMATICAL MODELS
PARTICLE MODELS
QUANTUM FIELD THEORY
STORAGE RINGS
SYNCHROTRONS
UNIFIED GAUGE MODELS
UNIFIED-FIELD THEORIES