相关论文: First second of leptons
In the early Universe above the weak scale, both baryon $B$ and lepton $L$ numbers are violated by nonperturabive effects in the Standard Model while $B-L$ remains conserved. Introducing new physics which violates perturbatively $L$ and/or…
We study flavor oscillations in the early universe, assuming primordial neutrino-antineutrino asymmetries. Including collisions and pair processes in the kinetic equations, we not only estimate the degree of flavor equilibration, but for…
We explore the possibility that lepton family numbers and baryon number are such good symmetries of Nature because they are the global remnant of a spontaneously broken gauge symmetry. An almost arbitrary linear combination of these…
In a pure inverse seesaw framework, achieving a substantial lepton asymmetry that can be converted into the observed baryon asymmetry of the Universe is extremely challenging. The difficulty arises primarily due to two reasons, (i) partial…
We use the Wilkinson Microwave Anisotropy Probe (WMAP) data on the spectrum of cosmic microwave background anisotropies to put constraints on the present amount of lepton asymmetry L, parameterized by the dimensionless chemical potential…
The cosmological baryon asymmetry can be explained as remnant of heavy Majorana neutrino decays in the early universe. We study this mechanism for two models of neutrino masses with a large \nu_\mu-\nu_\tau mixing angle which are based on…
We study leptogenesis from the out-of-equilibrium decays of the lightest heavy neutrino $N_1$ in the medium (low) temperature regime, $T\lsim 10^{12}$ GeV ($10^{10}$ GeV), where the rates of processes mediated by the $\tau$ (and $\mu$)…
Large primordial lepton flavor asymmetries with almost vanishing total baryon-minus-lepton number can evade the usual BBN and CMB constraints if neutrino oscillations lead to perfect flavor equilibration. Solving the momentum averaged…
We propose a resonant leptogenesis scenario in a U(1)_{B-L} gauge extension of the standard model to generate large lepton asymmetries for cosmological baryon asymmetry and dark matter. After B-L number is spontaneously broken, inflaton can…
We explore constraints on the parameter space of the alternative left-right model originating from the leptonic sector. Our analyses focuses on both lepton-flavour-conserving observables, particularly the anomalous magnetic moment of the…
We give analytic approximations to the baryon asymmetry produced by thermal leptogenesis with hierarchical right-handed neutrinos. Our calculation includes flavour-dependent washout processes and CP violation in scattering, and neglects…
We investigate how a lepton asymmetry impacts the cosmic trajectory in the QCD phase diagram. We study the evolution of chemical potentials during the QCD epoch of the early Universe using susceptibilities from lattice QCD to interpolate…
Within a supersymmetric (SUSY) type-I seesaw framework with flavor-blind universal boundary conditions, we study the consequences of requiring that the observed baryon asymmetry of the Universe be explained by either thermal or non-thermal…
In supersymmetric standard models R-parity violating couplings are severely constrained, since otherwise they would erase the existing baryon asymmetry before the electroweak transition. It is often claimed that this cosmological constraint…
Cosmological constraints on grand unified theories with spontaneous lepton number violation are analysed. We concentrate on $SO(10)$, the simplest of the models possessing this property. It has been noted previously that the consistency of…
We consider an abelian extension of the Standard Model (SM) comprising a new gauge group $U(1)^\prime$, with the neutral gauge boson $Z^\prime$ having flavour violating couplings to quarks and leptons. The fermion content is the same as in…
We discuss flavour dependent lepton asymmetries in the Exceptional Supersymmetric Standard Model (E$_6$SSM). In the E$_6$SSM, the right-handed neutrinos do not participate in gauge interactions, and they decay into leptons and leptoquarks.…
The cosmological baryon asymmetry is closely related to neutrino properties due to the non-perturbative sphaleron processes in the high-temperature symmetric phase of the standard model. We review some aspects of this connection with…
The confirmation of the discrepancy with the Standard Model predictions in the anomalous magnetic moment by the Muon g-2 experiment at Fermilab points to a low scale of new physics. Flavour symmetries broken at low energies can account for…
We present a simple extension of the Standard Model with three right-handed neutrinos in a SUSY framework, with an additional U(1$)_\text{F}$ abelian flavor symmetry with a non standard leptonic charge $L_e-L_\mu-L_\tau$ for lepton doublets…