We study the possibility of texture zeros in Majorana light neutrino mass matrix in the light of dark large mixing angle (DLMA) solution to solar neutrino problem where solar mixing angle ($\sin^2{θ_{12}}\simeq 0.7 $) lies in the second octant instead of first octant in standard large mixing angle (LMA) scenario ($\sin^2{θ_{12}}\simeq 0.3 $). In three neutrino scenario, we find that LMA and DLMA solutions lead to different set of allowed and disallowed textures with one and two zeros. While being consistent with existing bounds from neutrino oscillation data, neutrinoless double beta decay and cosmology these allowed textures also lead to interesting correlations among light neutrino parameters which can distinguish LMA from DLMA solution. We also check the implications for texture zeros in $3+1$ neutrino scenario using both LMA and DLMA solutions. While LMA and DLMA solutions do not play decisive role in ruling out texture zeros in this case, they do give rise to distinct predictions and correlations between light neutrino parameters.
We analyze the effect of the Dark-large mixing angle (DLMA) solution on the effective Majorana mass ($m_{ββ}$) governing neutrino-less double beta decay ($0νββ$) in the presence of a sterile neutrino. We consider the 3+1 picture, comprising of one additional sterile neutrino. We have checked that the MSW resonance in the sun can take place in the DLMA parameter space in this scenario. Next we investigate how the values of the solar mixing angle $θ_{12}$ corresponding to the DLMA region alter the predictions of $m_{ββ}$ including a sterile neutrino in the analysis. We also compare our results w…
In the light of refined and large reactor mixing angle $θ_{13}$, we have revisited the texture three and two zero neutrino mass matrices in the flavor basis. For Majorana neutrinos, it has been explicitly shown that all the texture three zero mass matrices remain ruled out. Further, for both normal and inverted mass ordering, for the texture two zero neutrino mass matrices one finds interesting constraints on the Dirac-like CP violating phase $δ$ and Majorana phases $ρ$ and $σ$.
In this review, we present a derivation of the on-shell renormalization conditions for scalar and fermionic fields in theories with and without parity conservation. We also discuss the specifics of Majorana fermions. Our approach only assumes a canonical form for the renormalized propagators and exploits the fact that the inverse propagators are non-singular in $\varepsilon = p^2 - m_n^2$, where $p$ is the external four-momentum and $m_n$ is a pole mass. In this way, we obtain full agreement with commonly used on-shell conditions. We also discuss how they are implemented in renormalization.
We revisit the minimal supersymmetric SU(5) grand unified theory with three right-handed neutrinos in which universality conditions for soft-supersymmetry breaking parameters are imposed at an input scale above the unification scale. If the Majorana masses for the neutrinos are around $10^{15}$ GeV, large mixing angles and phases in the neutrino sector lead to flavor-violation and CP-violation in the right-handed down squark and left-handed slepton sectors. Since the observed Higgs boson mass and the proton decay constraints indicate sfermions have masses larger than a few TeV, flavor and CP c…
Current experimental sensitivity on neutrino magnetic moments is many orders of magnitude above the Standard Model prediction. A potential measurement of next-generation experiments would therefore strongly request new physics beyond the Standard Model. However, large neutrino magnetic moments generically tend to induce large corrections to the neutrino masses and lead to fine-tuning. We show that in a model where neutrino masses are proportional to neutrino magnetic moments. We revisit, discuss and propose mechanisms that still provide theoretical consistent explanations for a potential measu…
We study the phenomenology of scotogenic model in the case of Majorana Dark Matter (DM) candidate. This scenario gives important consequences since the parameter space of the model is almost unconstrained compared to the Inert Higgs Doublet Model (or the scotogenic model with scalar DM), and hence, offers new opportunities for discovery at future high energy collider, e.g. the HL-LHC. As an example, we focus on the production of the Standard Model (SM) Higgs boson in association with a pair of dark scalars. Owing to its clean signature, the $γγ$ decay channel of the SM Higgs boson is investiga…
A plausible explanation for the lightness of neutrino masses is that neutrinos are massless at tree level, with their mass (typically Majorana) being generated radiatively at one or more loops. The new couplings, together with the suppression coming from the loop factors, imply that the new degrees of freedom cannot be too heavy (they are typically at the TeV scale). Therefore, in these models there are no large mass hierarchies and they can be tested using different searches, making their detailed phenomenological study very appealing. In particular, the new particles can be searched for at c…
The interaction of neutrino transition magnetic dipole moments with magnetic fields can give rise to the phenomenon of neutrino spin-flavour precession (SFP). For Majorana neutrinos, the combined action of SFP of solar neutrinos and flavour oscillations would manifest itself as a small, yet potentially detectable, flux of electron antineutrinos coming from the Sun. Non-observation of such a flux constrains the product of the neutrino magnetic moment $μ$ and the strength of the solar magnetic field $B$. We derive a simple analytical expression for the expected $\barν_e$ appearance probability i…
Bilarge mixing matrix and its invariance under "horizontal conjugation" -- a new discrete transformation for neutrinos
在本文的第一部分，我们考虑了中微子的结构，其中狄拉克质量和右手马约拉纳质量是成比例的。如果前者也与带电轻子质量近似成正比，那么取$Δm^2_{32}\sim3\times 10^{-3}$ eV $^2$，我们近似估计为$Δm^2_{21}\sim{\cal O}(10^{-5}$ eV $^2)$，这与最近Kamland估计的$Δm^2_{21}\sim7\times 10^{-5}$ eV $^2$没有很大区别，与LMA太阳解一致。在第二部分中，我们一般地证明了中微子混合矩阵在同时离散变换$ν_e\to-ν_e$，$ν_μ\toν_τ$，$ν_τ\toν_μ$和$ν_1\to-ν_1$，$ν_2\to-ν_2$，$ν_3\toν_3$（中微子的"水平共轭"）下的{\it表征}混合矩阵的常见的双大形式，目前唯象地受到青睐。然后，在这种形式的情况下，质量中微子$ν_1$、$ν_2$、$ν_3$在它们的混合中得到一个新的量子数，{\it协变量}（中微子"水平宇称"，分别等于$-1,-1, 1$）。相反，这样的协方差可以是双大型混合矩阵的{PDMATHAMR原点}。在第5节中，“横向奇偶性”嵌入了一个组结构。
