# Light Dirac neutrino in left-right-symmetric models

## Abstract

Recent experiments related to neutrino mass and neutrinoless double-..beta.. decay suggest that the electron neutrino is a Dirac particle with its mass of the order of 10--20 eV. In most of the existing grand-unified scenarios neutrinos turn out to be Majorana particles, unless an arbitrarily small Yukawa coupling and/or Higgs-field vacuum expectation value is introduced. In this paper we propose a model where one can readily accommodate an ultralight Dirac neutrino. It has been pointed out that any left-right-symmetric model with a second set of heavier fermions can have an ultralight Dirac neutrino, if the global symmetry which prevents any mixing between the two sets of fermions allows a mixing between antifermions and the heavier fermion. The complete potential has been minimized to obtain the mass matrix. It is shown that the required symmetry-breaking mass scales for the present case are consistent with low-energy values of sinX sup 2 theta sub w: and ..cap alpha../sub s/.

- Authors:

- Publication Date:

- Research Org.:
- Institute of Physics, Bhubaneswar 751005, India

- OSTI Identifier:
- 6771486

- Alternate Identifier(s):
- OSTI ID: 6771486

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Phys. Rev. D; (United States); Journal Volume: 35:3

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ELECTRON NEUTRINOS; MASS; BETA DECAY; DIRAC EQUATION; FERMIONS; GRAND UNIFIED THEORY; HIGGS MODEL; LAGRANGIAN FUNCTION; MAJORANA THEORY; SO-10 GROUPS; SU-5 GROUPS; SUPERSYMMETRY; SYMMETRY BREAKING; YUKAWA POTENTIAL; DECAY; DIFFERENTIAL EQUATIONS; ELEMENTARY PARTICLES; EQUATIONS; FIELD THEORIES; FUNCTIONS; LEPTONS; LIE GROUPS; MASSLESS PARTICLES; MATHEMATICAL MODELS; NEUTRINOS; NUCLEAR POTENTIAL; PARTIAL DIFFERENTIAL EQUATIONS; PARTICLE MODELS; POTENTIALS; SO GROUPS; SU GROUPS; SYMMETRY; SYMMETRY GROUPS; UNIFIED GAUGE MODELS; UNIFIED-FIELD THEORIES; WAVE EQUATIONS 645202* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Electromagnetic Interactions & Properties; 645400 -- High Energy Physics-- Field Theory

### Citation Formats

```
Mishra, S., Misra, S.P., Panda, S., and Sarkar, U.
```*Light Dirac neutrino in left-right-symmetric models*. United States: N. p., 1987.
Web. doi:10.1103/PhysRevD.35.975.

```
Mishra, S., Misra, S.P., Panda, S., & Sarkar, U.
```*Light Dirac neutrino in left-right-symmetric models*. United States. doi:10.1103/PhysRevD.35.975.

```
Mishra, S., Misra, S.P., Panda, S., and Sarkar, U. Sun .
"Light Dirac neutrino in left-right-symmetric models". United States. doi:10.1103/PhysRevD.35.975.
```

```
@article{osti_6771486,
```

title = {Light Dirac neutrino in left-right-symmetric models},

author = {Mishra, S. and Misra, S.P. and Panda, S. and Sarkar, U.},

abstractNote = {Recent experiments related to neutrino mass and neutrinoless double-..beta.. decay suggest that the electron neutrino is a Dirac particle with its mass of the order of 10--20 eV. In most of the existing grand-unified scenarios neutrinos turn out to be Majorana particles, unless an arbitrarily small Yukawa coupling and/or Higgs-field vacuum expectation value is introduced. In this paper we propose a model where one can readily accommodate an ultralight Dirac neutrino. It has been pointed out that any left-right-symmetric model with a second set of heavier fermions can have an ultralight Dirac neutrino, if the global symmetry which prevents any mixing between the two sets of fermions allows a mixing between antifermions and the heavier fermion. The complete potential has been minimized to obtain the mass matrix. It is shown that the required symmetry-breaking mass scales for the present case are consistent with low-energy values of sinX sup 2 theta sub w: and ..cap alpha../sub s/.},

doi = {10.1103/PhysRevD.35.975},

journal = {Phys. Rev. D; (United States)},

number = ,

volume = 35:3,

place = {United States},

year = {Sun Feb 01 00:00:00 EST 1987},

month = {Sun Feb 01 00:00:00 EST 1987}

}