# Baryon asymmetry via leptogenesis in a neutrino mass model with complex scaling

## Abstract

Baryogenesis via leptogenesis is investigated in a specific model of light neutrino masses and mixing angles. The latter was proposed on the basis of an assumed complex-extended scaling property of the neutrino Majorana mass matrix M {sub ν}, derived with a type-1 seesaw from a Dirac mass matrix m {sub D} and a heavy singlet neutrino Majorana mass matrix M {sub R} . One of its important features, highlighted here, is that there is a common source of the origin of a nonzero θ{sub 13} and the CP violating lepton asymmetry through the imaginary part of m {sub D} . The model predicted CP violation to be maximal for the Dirac type and vanishing for the Majorana type. We assume strongly hierarchical mass eigenvalues for M {sub R} . The leptonic CP asymmetry parameter ε{sup α}{sub 1} mm with lepton flavor α, originating from the decays of the lightest of the heavy neutrinos N {sub 1} (of mass M {sub 1}) at a temperature T ∼ M {sub 1}, is what matters here with the lepton asymmetries, originating from the decays of N {sub 2,3}, being washed out. The light leptonic and heavy neutrino number densities (normalized to the entropymore »

- Authors:

- Saha Institute of Nuclear Physics, HBNI, 1/AF Bidhannagar, Kolkata 700064 (India)
- Centre of Excellence in Theoretical and Mathematical Sciences, SOA University, Khandagiri Square, Bhubaneswar 751030 (India)
- Center for Astroparticle Physics and Space Science, Bose Institute, Kolkata 700091 (India)

- Publication Date:

- OSTI Identifier:
- 22679980

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 03; Other Information: Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; BARYONS; BOLTZMANN EQUATION; CP INVARIANCE; DENSITY; ENTROPY; FLAVOR MODEL; GEV RANGE; MAJORANA SPINORS; MASS; MIXING ANGLE; NEUTRINO OSCILLATION; NEUTRINOS; PARTICLE PRODUCTION; SENSITIVITY; UNIVERSE; VISIBLE RADIATION

### Citation Formats

```
Samanta, Rome, Ghosal, Ambar, Chakraborty, Mainak, and Roy, Probir, E-mail: rome.samanta@saha.ac.in, E-mail: mainak.chakraborty2@gmail.com, E-mail: probirrana@gmail.com, E-mail: ambar.ghosal@saha.ac.in.
```*Baryon asymmetry via leptogenesis in a neutrino mass model with complex scaling*. United States: N. p., 2017.
Web. doi:10.1088/1475-7516/2017/03/025.

```
Samanta, Rome, Ghosal, Ambar, Chakraborty, Mainak, & Roy, Probir, E-mail: rome.samanta@saha.ac.in, E-mail: mainak.chakraborty2@gmail.com, E-mail: probirrana@gmail.com, E-mail: ambar.ghosal@saha.ac.in.
```*Baryon asymmetry via leptogenesis in a neutrino mass model with complex scaling*. United States. doi:10.1088/1475-7516/2017/03/025.

```
Samanta, Rome, Ghosal, Ambar, Chakraborty, Mainak, and Roy, Probir, E-mail: rome.samanta@saha.ac.in, E-mail: mainak.chakraborty2@gmail.com, E-mail: probirrana@gmail.com, E-mail: ambar.ghosal@saha.ac.in. Wed .
"Baryon asymmetry via leptogenesis in a neutrino mass model with complex scaling". United States.
doi:10.1088/1475-7516/2017/03/025.
```

```
@article{osti_22679980,
```

title = {Baryon asymmetry via leptogenesis in a neutrino mass model with complex scaling},

author = {Samanta, Rome and Ghosal, Ambar and Chakraborty, Mainak and Roy, Probir, E-mail: rome.samanta@saha.ac.in, E-mail: mainak.chakraborty2@gmail.com, E-mail: probirrana@gmail.com, E-mail: ambar.ghosal@saha.ac.in},

abstractNote = {Baryogenesis via leptogenesis is investigated in a specific model of light neutrino masses and mixing angles. The latter was proposed on the basis of an assumed complex-extended scaling property of the neutrino Majorana mass matrix M {sub ν}, derived with a type-1 seesaw from a Dirac mass matrix m {sub D} and a heavy singlet neutrino Majorana mass matrix M {sub R} . One of its important features, highlighted here, is that there is a common source of the origin of a nonzero θ{sub 13} and the CP violating lepton asymmetry through the imaginary part of m {sub D} . The model predicted CP violation to be maximal for the Dirac type and vanishing for the Majorana type. We assume strongly hierarchical mass eigenvalues for M {sub R} . The leptonic CP asymmetry parameter ε{sup α}{sub 1} mm with lepton flavor α, originating from the decays of the lightest of the heavy neutrinos N {sub 1} (of mass M {sub 1}) at a temperature T ∼ M {sub 1}, is what matters here with the lepton asymmetries, originating from the decays of N {sub 2,3}, being washed out. The light leptonic and heavy neutrino number densities (normalized to the entropy density) are evolved via Boltzmann equations down to electroweak temperatures to yield a baryon asymmetry through sphaleronic transitions. The effects of flavored vs. unflavored leptogenesis in the three mass regimes (1) M {sub 1} < 10{sup 9} GeV, (2) 10{sup 9} GeV < M {sub 1} < 10{sup 12} GeV and (3) M {sub 1} > 10{sup 12} GeV are numerically worked out for both a normal and an inverted mass ordering of the light neutrinos. Corresponding results on the baryon asymmetry of the universe are obtained, displayed and discussed. For values close to the best-fit points of the input neutrino mass and mixing parameters, obtained from neutrino oscillation experiments, successful baryogenesis is achieved for the mass regime (2) and a normal mass ordering of the light neutrinos with a nonzero θ{sub 13} playing a crucial role. However, the other possibility of an inverted mass ordering for the same mass regime, though disfavored, cannot be excluded. A discussion is also given on the sensitivity of our result to the masses M {sub 2,3} of the heavier neutrinos N {sub 2,3}.},

doi = {10.1088/1475-7516/2017/03/025},

journal = {Journal of Cosmology and Astroparticle Physics},

number = 03,

volume = 2017,

place = {United States},

year = {Wed Mar 01 00:00:00 EST 2017},

month = {Wed Mar 01 00:00:00 EST 2017}

}