| Title: |
Flavour covariant transport equations:An application to resonant leptogenesis |
| Authors: |
Dev, PSB; Millington, P; Pilaftsis, A; Teresi, D |
| Source: |
Dev, PSB, Millington, P, Pilaftsis, A & Teresi, D 2014, 'Flavour covariant transport equations : An application to resonant leptogenesis', NUCLEAR PHYSICS B, vol. 886, pp. 569-664. https://doi.org/10.1016/j.nuclphysb.2014.06.020 |
| Publication Year: |
2014 |
| Collection: |
The University of Manchester: Research Explorer - Publications |
| Subject Terms: |
Flavour Covariance; Discrete Symmetries; Transport Equations; Resonant Leptogenesis |
| Description: |
We present a fully flavour-covariant formalism for transport phenomena, by deriving Markovian master equations that describe the time-evolution of particle number densities in a statistical ensemble with arbitrary flavour content. As an application of this general formalism, we study flavour effects in a scenario of resonant leptogenesis (RL) and obtain the flavour-covariant evolution equations for heavy-neutrino and lepton number densities. This provides a complete and unified description of RL, capturing three distinct physical phenomena: (i) the resonant mixing between the heavy-neutrino states, (ii) coherent oscillations between different heavy-neutrino flavours, and (iii) quantum decoherence effects in the charged-lepton sector. To illustrate the importance of this formalism, we numerically solve the flavour-covariant rate equations for a minimal RL model and show that the total lepton asymmetry can be enhanced by up to one order of magnitude, as compared to that obtained from flavour-diagonal or partially flavour off-diagonal rate equations. Thus, the viable RL model parameter space is enlarged, thereby enhancing further the prospects of probing a common origin of neutrino masses and the baryon asymmetry in the Universe at the LHC, as well as in low-energy experiments searching for lepton flavour and number violation. The key new ingredients in our flavour-covariant formalism are rank-4 rate tensors, which are required for the consistency of our flavour-mixing treatment, as shown by an explicit calculation of the relevant transition amplitudes by generalizing the optical theorem. We also provide a geometric and physical interpretation of the heavy-neutrino degeneracy limits in the minimal RL scenario. Finally, we comment on the consistency of various suggested forms for the heavy-neutrino self-energy regulator in the lepton-number conserving limit. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| ISSN: |
0550-3213; 1873-1562 |
| Relation: |
info:eu-repo/semantics/altIdentifier/wos/000341344500023; info:eu-repo/semantics/altIdentifier/pissn/0550-3213; info:eu-repo/semantics/altIdentifier/eissn/1873-1562 |
| DOI: |
10.1016/j.nuclphysb.2014.06.020 |
| Availability: |
https://research.manchester.ac.uk/en/publications/d9db28ed-afcd-4eda-af40-cee4d1307e0b; https://doi.org/10.1016/j.nuclphysb.2014.06.020 |
| Rights: |
info:eu-repo/semantics/openAccess |
| Accession Number: |
edsbas.77E355C4 |
| Database: |
BASE |