We present a model-independent analysis of Leptonic CP violation for some well known mixing scenarios. In particular, we considered modified schemes for Bimaximal(BM), Democratic(DC), Hexagonal(HG) and Tribimaixmal(TBM) mixing for our numerical investigation. These model-independent corrections to mixing matrices are parameterized in terms of complex rotation matrices ($U$) with related modified PMNS matrix of the forms \big($U_{ij}^l\cdot V_{M},~V_{M}\cdot U_{ij}^r$ \big ) where $U_{ij}^{l, r}$ is complex rotation in ij sector and $V_{M}$ is unperturbed mixing scheme. We present generic formulae for mixing angles, Dirac CP phase($δ_{CP}$) and Jarkslog Invariant($J_{CP}$) in terms of correction parameters. The parameter space of each modified mixing case is scanned for fitting neutrino mixing angles using $χ^2$ approach and the corresponding predictions for Leptonic CP Phase($δ_{CP}$) and Jarkslog Invariant($J_{CP}$) has been evaluated from allowed parameter space. The obtained ranges are reported for all viable cases.
We explore the theoretical constraints on the observable parameters of neutrino mixing on predictions for the leptonic Dirac CP-violating phase within a well-studied class of simple theoretical models that includes a single source of CP violation due to charged lepton corrections. The approach guarantees that a physically meaningful prediction for the most likely values for the leptonic Dirac CP-violating phase is obtained.
We propose a new mechanism to explain neutrino masses with lepton number conservation, in which the Dirac neutrino masses are generated at the two-loop level involving a dark matter candidate. In this model, branching ratios of lepton flavor violating decays of the Higgs boson can be much larger than those of lepton flavor violating decays of charged leptons. If lepton flavor violating decays of the Higgs boson are observed at future collider experiments without detecting lepton flavor violating decays of charged leptons, most of the models previously proposed for tiny neutrino masses are excl…
We propose an idea that the observed CP violation in neutrino oscillation is originated from the phase in right-handed neutrino mixing by seesaw mechanism. We add small breaking terms $M_{ij}N_{R_i}N_{R_j} $ in model based on $A_4$ symmetry to generate non-diagonal right-handed neutrino mixing, which will give a small correction to TBM mixing via seesaw mechanism with nonzero reactor angle and CP violating phase. We estimate the CP violating phase by investigating the process of leptogenesis due to the decay of right-handed neutrino.
We explore the implications of recent results relating the Dirac CP-violating phase to predicted and measured leptonic mixing angles within a standard set of theoretical scenarios in which charged lepton corrections are responsible for generating a non-zero value of the reactor mixing angle. We employ a full set of leptonic sum rules as required by the unitarity of the lepton mixing matrix, which can be reduced to predictions for the observable mixing angles and the Dirac CP-violating phase in terms of model parameters. These sum rules are investigated within a given set of theoretical scenari…
The hypothetical dark photon portal connecting the visible and dark sectors of the Universe has received considerable attention in recent years, with a focus on CP-conserving kinetic mixing between the Standard Model (SM) hypercharge gauge boson and a new U(1)$_X$ gauge boson. In the effective field theory context, one may write down non-renormalizable CP-violating kinetic mixing interactions involving the $X$ and SU(2)$_L$ gauge bosons. We construct for the first time a renormalizable model for CP-violating kinetic mixing that induces CP-violating non-Abelian kinetic mixing at mass dimension …
We update and improve past efforts to predict the leptonic Dirac CP-violating phase with models that predict perturbatively modified tribimaximal or bimaximal mixing. Simple perturbations are applied to both mixing patterns in the form of rotations between two sectors. By translating these perturbed mixing matrices to the standard parameterization for the neutrino mixing matrix we derive relations between the Dirac CP-phase and the oscillation angles. We use these relations together with current experimental results to constrain the allowed range for the CP-phase and determine its probability …
This dissertation investigates the flavor mixing effects in supersymmetric models on electroweak precision observables, Higgs boson mass predictions, B-physics observables, quark flavor violating Higgs decays, lepton flavor violating charged lepton decays and lepton flavor violating Higgs decays. The flavor mixing effects are studied in model independent way i.e. by putting off-diagonal entries in the sfermion mass matrix by hand as well as in the minimal flavor violating constrained MSSM, where mixing can originate from CKM matrix in the case of squarks and from PMNS matrix in the case of sle…
A Novel Parametrization of tau-lepton Dominance and Simplified One-loop Renormalization-group Equations of Neutrino Mixing Angles and CP-violating Phases
We present predictions for CP violating phases of the Type-I seesaw model with four-zero textures on the Dirac mass matrix. For the four-zero textures, the effective low energy Majorana mass matrix is parametrized with seven parameters. They are three mass-dimensional parameters, two angles and two CP violating sources. The number of these parameters is less than that of the general description of the Majorana mass matrix with three neutrino masses, three mixing angles and three CP violating phases. In particular, only two independent CP violating sources give rise to three CP violating phases…
We study lepton flavor violation in a class of supersymmetric models with light sgoldstino - scalar superpartner of Goldstone fermions responsible for spontaneous supersymmetry breaking. Sgoldstino couplings to the Standard Model (SM) fermions are determined by the MSSM soft terms and, in general, provide with flavor violation in this sector. Sgoldstino admixture to the lightest Higgs boson results in changes of its coupling constants and, in particular, leads to lepton flavor-violating decay $h\toτμ$ of the Higgs resonance. We discuss viability and phenomenological consequences of this scenar…
On-shell renormalization of neutralino and chargino mass matrices in R-parity violating models - Correlation between LSP decays and neutrino mixing angles revisited
If neutrinos are Dirac, the conditions for cobimaximal mixing, i.e. $θ_{23}=π/4$ and $δ_{CP}=\pm π/2$ in the $3 \times 3$ neutrino mixing matrix, are derived. One example with $A_4$ symmetry and radiative Dirac neutrino masses is presented.
R-parity violation and CP-violating and CP-conserving spin asymmetries in l^+ l^- -> sneutrino -> tau^+ tau^-: probing sneutrino mixing at LEP2, NLC and mu^+mu^- colliders
The current paper is a technical work that is focused on Lorentz violation for Dirac fermions as well as neutrinos, described within the nonminimal Standard-Model Extension. We intend to derive two theoretical results. The first is the full propagator of the single-fermion Dirac theory modified by Lorentz violation. The second is the dispersion equation for a theory of $N$ neutrino flavors that enables the description of both Dirac and Majorana neutrinos. As the matrix structure of the neutrino field operator is very involved for generic $N$, we will use sophisticated methods of linear algebra…
CP violation in neutrino interactions is described by three phases contained in Pontecorvo-Maki-Nakagawa-Sakata mixing matrix ($U_{PMNS}$). We argue that the phenomenologocally consistent result of the Dirac CP violation can be obtained if $U_{PMNS}$ is constructed along bipair neutrino mixing scheme, namely, requiring that $ | U_{12} | = | U_{32} | {\rm and} | U_{22} | = | U_{23} | (\rm case 1)$ and $ | U_{12} | = | U_{22} | {\rm and} | U_{32} | = | U_{33}| (\rm case 2)$, where $U_{ij}$ stands for the $i$-$j$ matrix element of $U_{PMNS}$. As a results, the solar, atmospheric and reactor neutr…
