Neutrino Cosmology after WMAP 7-Year Data and LHC First Z' Bounds
Abstract
The gauge-extended U(1)C×SU(2)L×U(1)IR×U(1)L model elevates the global symmetries of the standard model (baryon number B and lepton number L) to local gauge symmetries. The U(1)L symmetry leads to three superweakly interacting right-handed neutrinos. This also renders a B-L symmetry nonanomalous. The superweak interactions of these Dirac states permit νR decoupling just above the QCD phase transition: 175≲TνRdec/MeV≲250. In this transitional region, the residual temperature ratio between νL and νR generates extra relativistic degrees of freedom at BBN and at the CMB epochs. Consistency with both WMAP 7-year data and recent estimates of the primordial He4 mass fraction is achieved for 3<MB-L/TeV<6. The model is fully predictive, and can be confronted with dijet and dilepton data from LHC7 and, eventually, LHC14.
- Publication:
-
Physical Review Letters
- Pub Date:
- February 2012
- DOI:
- 10.1103/PhysRevLett.108.081805
- arXiv:
- arXiv:1111.7264
- Bibcode:
- 2012PhRvL.108h1805A
- Keywords:
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- 14.60.Pq;
- 12.60.Cn;
- 98.80.Cq;
- Neutrino mass and mixing;
- Extensions of electroweak gauge sector;
- Particle-theory and field-theory models of the early Universe;
- High Energy Physics - Phenomenology;
- Astrophysics - Cosmology and Extragalactic Astrophysics;
- General Relativity and Quantum Cosmology
- E-Print:
- References added