相关论文: Neutron Majorana mass from exotic instantons
We perform a joint analysis of current data from cosmology and laboratory experiments to constrain the neutrino mass parameters in the framework of bayesian statistics, also accounting for uncertainties in nuclear modeling, relevant for…
If the neutrino is Majorana type and the electroweak phase transition is second or weak first order, neutrino-induced interactions together with sphaleron transitions have the potential to erase a previously generated baryon asymmetry of…
A solution for the neutrino mass and mixing pattern is proposed which is compatible with all available experimental data on neutrino oscillations. This solution involves Majorana neutrinos of the pseudo-Dirac type, i.e. m_Majorana <<…
We consider an extension of the Standard Model by two right-handed neutrinos, especially with masses lighter than charged $K$ meson. This simple model can realize the seesaw mechanism for neutrino masses and also the baryogenesis by flavor…
We propose a new model where the Dirac mass term for neutrinos, the Majorana mass term for right-handed neutrinos, and the other new fermion masses arise via the spontaneous breakdown of the $U(1)_{B-L}$ gauge symmetry. The anomaly-free…
Addressing the mass origin and properties of neutrinos is of strong interest to particle physics, baryogenesis and cosmology. Popular explanations involve physics beyond the standard model, for example, the dimension-5 Weinberg operator or…
We have examined the importance of momentum dependent induced nucleon currents such as weak-magnetism and pseudoscalar couplings to the amplitude of neutrinoless double beta decay in the mechanisms of light and heavy Majorana neutrino as…
The fermionic nature of neutrinos and the origin of their tiny masses remain unresolved issues in particle physics, intrinsically connected to lepton number symmetry-conserved for Dirac, violated for Majorana, and effectively pseudo-Dirac…
We consider the possibility that the quark condensate formed by QCD confinement generates Majorana neutrino masses m_\nu via dimension seven operators. No degrees of freedom beyond the Standard Model are necessary, below the electroweak…
Assuming four-neutrino mixing and massive Majorana neutrinos, we study the implications of the neutrino oscillation solutions of the solar and atmospheric neutrino problems, of the results of the LSND experiment and of the constraints on…
The short-range part of the neutrinoless double beta amplitude is generated via the exchange of exotic particles, such as charged scalars, leptoquarks and/or diquarks. In order to give a sizeable contribution to the total decay rate, the…
This doctoral dissertation presents several works on nonstandard properties of neutrinos exploiting the synergies between effective field theory and models. The phenomena are first analysed by means of effective operators, which allow to…
We explore the possibility of interpreting the solar and atmospheric neutrino data within the context of the Minimal Supersymmetric Standard Model augmented by a single U(1) anomalous family symmetry spontaneously broken by non-zero vacuum…
With the help of current neutrino oscillation data, we illustrate the three-dimensional (3D) profiles of all the six distinct effective Majorana neutrino masses $|\langle m\rangle^{}_{\alpha \beta}|$ (for $\alpha, \beta = e, \mu, \tau$)…
We present simple and predictive realizations of neutrino masses in theories based on the $SU(6)$ grand unifying group. At the level of the lowest-dimension operators, this class of models predicts a skew-symmetric flavor structure for the…
We study Pontecorvo neutrino-antineutrino oscillations both in vacuum and in matter within a field theoretic approach, showing that this phenomenon can occur only if neutrinos have a Dirac-Majorana mass term. We find that matter effects…
Motivated by the Super-Kamiokande atmospheric neutrino data, we discuss possible textures for Majorana and Dirac neutrino masses within the see-saw framework. The main purposes of this paper are twofold: first to obtain intuition from a…
We have studied the constraints imposed by the results of neutrino oscillation experiments on the effective Majorana mass |<m>| that characterizes the contribution of Majorana neutrino masses to the matrix element of neutrinoless…
Heavy neutrino-antineutrino oscillations can naturally appear in mechanisms of low scale neutrino mass generation, where pairs of heavy neutrinos have almost degenerate masses. We discuss the case where the heavy neutrinos are sufficiently…
We show how R-parity can be dynamically broken by non-perturbative quantum gravity effects. In particular, in D-brane models, Exotic instantons provide a simple and calculable mechanism for the generation of R-parity violating bilinear,…