相关论文: Gravitational Waves from $\textit{Type-I}$ Strings…
The Inverse Seesaw scenario relates the smallness of the neutrino masses to a small $B-L$ breaking parameter. We investigate a possible dynamical generation of the Inverse Seesaw neutrino mass mechanism from the spontaneous breaking of a…
The type-I seesaw Lagrangian yields a non-generic set of active-sterile oscillation parameters - the neutrino mass eigenvalues and the physical elements of the full mixing matrix are entwined. For this reason one is able to, in principle,…
The mean spectrum and burst statistics of gravitational waves produced by a cosmological population of cosmic string loops are estimated using analytic approximations, calibrated with earlier simulations. Formulas are derived showing the…
The possibility of generating neutrino mass through see-saw mechanism involving U(1) chiral Peccei-Quinn and scale symmetries breakdown is discussed. We consider a generic scale invariant model which has three Majorana fermions and a…
Motivated by the see-saw mechanism for neutrinos which naturally generates small neutrino masses, we explore how a small GUT-scale mixing between the Standard Model Higgs and an otherwise massless hidden sector scalar can naturally generate…
Cosmic strings represent an attractive source of gravitational waves (GWs) from the early Universe. However, numerical computation of the GW signal from cosmic strings requires the evaluation of complicated integral and sum expressions,…
We investigate an alternative seesaw mechanism for neutrino mass generation. Neutrino mass is generated at loop level but the basic concept of usual seesaw mechanism is kept. One simple model is constructed to show how this mechanism is…
We introduce a novel hybrid framework combining type I and type II seesaw models for neutrino mass where a complex vacuum expectation value of a singlet scalar field breaks CP spontaneously. Using pragmatic organizing symmetries we…
In a class of gauged $U(1)$ extended Standard Models (SMs), the breaking of the $U(1)$ symmetry is not only a source for Majorana masses of right-handed (RH) neutrinos crucial for the seesaw mechanism, but also a source of stochastic…
In this paper, we propose a $G_{L-R}\times U(1)_{L_\mu-L_\tau}$ gauge-symmetric model where $G_{L-R}$ is the left-right gauge symmetry and $L_i$ is the $i-$flavor lepton number. We use the spontaneous breaking (SSB) of $U(1)_{L_\mu-L_\tau}$…
We propose models for neutrino masses and mixing in the framework of low scale $U(1)_{L_\mu-L_\tau}$ gauge extension of the standard model. The models are designed to spontaneously break $U(1)_{L_\mu-L_\tau}$ so that the…
We present how a neutrino condensate and small neutrino masses emerge from a topological formulation of gravitational anomaly. We first recapitulate how a gravitational $\theta$-term leads to the emergence of a new bound neutrino state…
We investigate the low-energy phenomenology of the Type-I seesaw mechanism within a 3+3 framework containing three active and three sterile neutrinos. Using the exact seesaw relation as a bridge between the high-scale sterile-sector…
The gravitational wave (GW) signals emitted by a network of cosmic strings are reexamined in view of the possible formation of a network of cosmic superstrings at the end of brane inflation. The reconnection probability $p$ of intersecting…
We present a predictive framework for neutrino mass generation based on the spontaneous breaking of a leptonic $U(1)_{L_\mu-L_\tau}$ symmetry within a supersymmetric setting. The breaking of the global symmetry gives rise to a Majoron-like…
The accessibility to physics responsible for tiny neutrino mass suggests that the mass should better originate from certain higher dimensional operators. The conventional three types of seesaw operate at dimension five with the help of…
The scattering and capture of right-handed neutrinos by an Abelian cosmic string in the SO(10) grand unification model are considered. The scattering cross-section of neutrinos per unit length due to the interaction with the gauge and Higgs…
We search for stochastic gravitational wave background emitted from cosmic strings using the Parkes Pulsar Timing Array data over 15 years. While we find that the common power-law excess revealed by several pulsar timing array experiments…
Cosmic strings, theoretical one-dimensional topological defects from the early universe, provide a valuable opportunity for exploring dark matter (DM) production and gravitational wave (GW) emission. Our study investigates the production of…
String theories in principle address the origin and values of the quark and lepton masses. Perhaps the small values of neutrino masses could be explained generically in string theory even if it is more difficult to calculate individual…