arXiv subjects

Ankush

Publications and source records attributed to Ankush.

7 recordsLinked to original sources

arXiv2025

Predictive one-zero with vanishing sub-trace texture in neutrino mass matrix in light of dark matter and neutrinoless double beta decay

In this work, we investigate a predictive class of neutrino mass matrices characterized by one texture zero and one vanishing sub-trace within the framework of the scotogenic model, wherein neutrino masses, dark matter, and neutrinoless double beta decay are intrinsically correlated. We analyze twelve viable texture structures -- namely $B_{1,4,5}$, $C_{1,2,\ldots,5}$, $D_{4,5}$, and $F_{5,6}$ -- and examine their implications for the effective Majorana mass $(|M_{ee}|)$ governing neutrinoless double beta decay $(0\nu\beta\beta)$. Remarkably, all non-zero entries of the neutrino mass matrix can be parametrized in terms of this effective Majorana mass, establishing a direct theoretical link between low-energy observables and high-scale parameters of the model. Among the twelve textures, eleven predict dark matter masses of order TeV and yield correlated bounds on $|M_{ee}|$ -- making them testable in current and forthcoming $0\nu\beta\beta$ experiments -- while the textures $D_4$ and $F_{5,6}$ exhibit comparatively weaker correlations. In contrast, the texture $C_5$ is excluded due to its requirement of unrealistically large Yukawa couplings and its inability to realize dark matter in the TeV regime. Our analysis thus identifies a subset of predictive neutrino mass textures that consistently relate dark matter phenomenology and neutrinoless double beta decay observables within the scotogenic paradigm.

hep-ph↗

arXiv2024

Electron and Muon $(g-2)_{e,\mu}$ Anomalous Magnetic Moment in $U(1)_{L_e-L_{\mu}}$ Symmetry Model

The nature of neutrino (whether Majorana or Dirac) and the origin of neutrino masses are still some of the mysteries to be resolved. Also, the recent results on (g-2)$_{e,\mu}$ measurements deviate from the Standard Model (SM) predictions and motivate us towards new physics beyond the SM. In this work, we propose a model with the minimal field content in the framework of anomaly free extension of Standard Model; i.e. U(1)$_{L_e-L_{\mu}}$ symmetry model. We find this model capable of explaining the low energy neutrino phenomenology and anomalous magnetic moment(g-2)$_{e,\mu}$ of electron and muon, simultaneously. The field content is extended by a SU(2)$_L$ singlet scalar field $\phi$ and three right handed neutrinos N$_R$(R = 1,2,3). Thus, the neutrino masses are generated using the Type-I seesaw mechanism. The extended model leads to the results, which are in consistency with the experimental values of (g-2)$_{e,\mu}$ and also satisfy all the relevant experimental data.

hep-ph↗

arXiv2023

Mixed convection instability in a viscosity stratified flow in a vertical channel

The present study examines the linear instability characteristics of double-diffusive mixed convective flow in a vertical channel with viscosity stratification. The viscosity of the fluid is modelled as an exponential function of temperature and concentration, with an activation energy parameter determining its sensitivity to temperature variation. Three scenarios are considered: buoyancy force due to thermal diffusion only, buoyancy force due to temperature and solute acting in the same direction, and buoyancy force due to temperature and solute acting in opposite directions. A generalized eigenvalue problem is derived and solved numerically for linear stability analysis via the Chebyshev spectral collocation method. Results indicate that higher values of the activation energy parameter lead to increased flow stability. Additionally, when both buoyant forces act in opposite directions, the Schmidt number has both stabilizing and destabilizing effects across the range of activation energy parameters, similar to the case of pure thermal diffusion. Furthermore, the solutal-buoyancy-opposed base flow is found to be the most stable, while the solutal-buoyancy-assisted base flow is the least stable. As expected, an increase in Reynolds number is shown to decrease the critical Rayleigh number.

physics.flu-dyn↗

arXiv2023

Leptogenesis and Neutrinoless Double Beta Decay in the Scotogenic Hybrid Textures of Neutrino Mass Matrix

In our recent work we identify the hybrid textures of neutrino mass matrix which simultaneously account for dark matter (DM) and neutrinoless double beta decay ($0\nu\beta\beta$). We also obtained the bounds on dark matter mass and effective Majorana mass $|M_{ee}|$. In this work we look for those hybrid textures which altogether accounts for DM, $0\nu\beta\beta$ and leptogenesis. We have found correlation of baryon asymmetry of universe $Y$ with dark matter mass $M_1$ and effective Majorana mass $|M_{ee}|$. We use experimental bounds on relic density of dark matter ($\Omega h^2$) and baryon asymmetry of universe to identify the hybrid textures. We found that out of five hybrid textures which simultaneously satisfies the physics observations of the DM and $0\nu\beta\beta$ only three hybrid textures altogether satisfy the DM, $0\nu\beta\beta$ and leptogenesis. It is interesting to note that these three hybrid textures gives lower bound to the effective Majorana mass $|M_{ee}|$ which can be probed in current and future experiments like SuperNEMO, KamLAND-Zen, NEXT, and nEXO (5 year) have sensitivity reaches of 0.05 eV, 0.045 eV, 0.03 eV, and 0.015 eV, respectively.

hep-ph↗

arXiv2023

Dark Matter and $(g-2)_{e,\mu}$ in ISS(2,3) based Gauged $U(1)_{L_{e}-L{\mu}}$ Symmetric Model

We proposed a model which can explain the neutrino phenomenology, dark matter and anomalous magnetic moment$(g-2)$ in a common framework. The inverted sea saw (ISS)(2,3) mechanism has been incorporated, in which we get an extra sterile state and this state act as a viable dark matter candidate. The right handed neutrino mass is obtained in TeV scale, which is accessible at LHC. The anomaly free $U(1)_{L_{e}-L{\mu}}$ gauge symmetry is introduced to explain the anomalous magnetic moment of electron and muon because it provides a natural origin of $(g-2)$ in a very minimal setup. The corresponding MeV scale gauge boson successfully explain the anomalous magnetic moment of electron and muon$(g-2)_{e,\mu}$, simultaneously. Thus obtained neutrino phenomenology and relic abundance of dark matter are compatible with experimental results.

hep-ph↗

arXiv2021

Scotogenesis in Hybrid Textures of Neutrino Mass Matrix and Neutrinoless Double Beta Decay

We study the connection between dark matter (DM) and neutrinoless double beta ($0\nu\beta\beta$) decay in a scotogenic model with hybrid texture in the neutrino mass matrix. Characteristically, the framework allows to write all the non-zero elements of the mass matrix proportional to effective Majorana mass $\left|M_{ee}\right|$. The overall scale of the neutrino mass is found to be governed by non-zero $\left|M_{ee}\right|$. We have obtained interesting correlations of relic density of DM($\Omega h^2$) with DM mass $M_1$ and $\left|M_{ee}\right|$. Using experimental value of DM relic density($\Omega h^2$), the DM mass $M_1$, is found to be $\mathcal{O}$(1TeV) which is within reach of collider experiments. Specifically, for all five hybrid textures, the range of upper bound on DM mass $M_1$ is found to be ($2.27$-$5.31$)TeV. Another interesting feature of the model is the existence of lower bound on $|M_{ee}|$ for all allowed hybrid textures except texture $T_5$ which can be probed in current and future $0\nu\beta\beta$ decay experiments. With high sensitivities, these experiments shall establish the theoretical status of the proposed model. For example, the non-observation of $0\nu\beta\beta$ decay down to the sensitivity $\mathcal{O}(0.03)$eV will refute $T_3$ hybrid texture.

hep-ph↗

arXiv2018

Investigating Sterile Neutrino Flux in the Solar Neutrino Data

There are compelling evidences for the existence of a fourth degree of freedom of neutrinos i.e. sterile neutrino. In the recent studies the role of sterile component of neutrinos has been found to be crucial, not only in particle physics, but also in astrophysics and cosmology. This has been proposed to be one of the potential candidates of dark matter. In this work we investigate the updated solar neutrino data available from all the relevant experiments including Borexino and KamLAND solar phase in a model independent way, and obtain bounds on the sterile neutrino component present in the solar neutrino flux. The mystery of the missing neutrinos is further deepening as subsequent experiments are coming up with their results. The energy spectrum of solar neutrinos, as predicted by Standard Solar Models (SSM), is seen by neutrino experiments at different parts as they are sensitive to various neutrino energy ranges. It is interesting to note that more than $98\%$ of the calculated standard model solar neutrino flux lies below $1MeV$. Therefore, the study of low energy neutrinos can give us better understanding and the possibility to know about the presence of antineutrino and sterile neutrino components in solar neutrino flux. As such, this work becomes interesting as we include the data from medium energy ($\sim 1MeV$) experiments i.e. Borexino and KamLAND solar phase. In our study we retrieve the bounds existing in literature, and rather provide more stringent limits on sterile neutrino($\nu_{s}$) flux available in solar neutrino data.

hep-ph↗