Lepton Masses in a Minimal Model with Triplet Higgs Bosons and S3S_3 Flavor Symmetry

Viable neutrino and charged lepton masses and mixings are obtained by imposing a $S_3 \times Z_4 \times Z_3$ flavor symmetry in a model with a few additional Higgs. We use two $SU(2)_L$ triplet Higgs which are arranged as a doublet of $S_3$, and standard model singlet Higgs which are also put as doublets of $S_3$. We break the $S_3$ symmetry in this minimal model by giving vacuum expectation values (VEV) to the additional Higgs fields. Dictated by the minimum condition for the scalar potential, we obtain certain VEV alignments which allow us to maintain $\mu-\tau$ symmetry in the neutrino sector, while breaking it maximally for the charged leptons. This helps us to simultaneously explain the hierarchical charged lepton masses, and the neutrino masses and mixings. In particular, we obtain maximal $\theta_{23}$ and zero $\theta_{13}$. We allow for a mild breaking of the $\mu-\tau$ symmetry for the neutrinos and study the phenomenology. We give predictions for $\theta_{13}$ and the CP violating Jarlskog invariant $J_{CP}$, as a function of the $\mu-\tau$ symmetry breaking parameter. We also discuss possible collider signatures and phenomenology associated with lepton flavor violating processes.Comment: 29 pages, 5 figures. Version to be appeared in PRD. Phenomenology of Lepton flavor violation and possible collider signatures of this model have been include

A Note on Estimation of Population Mean in Sample Survey using Auxiliary Information

In this paper we have suggested a class of estimators for population mean using auxiliary information in two-phase sampling. When the population mean  is not known, a class of estimators for finite population mean  of the study variable y has been suggested. Expressions of bias and mean squared error are obtained upto the first order of approximation. Asymptotically optimum estimators (AOE’s) are also identified with its mean squared error formula. We found that proposed class of estimator are better than usual ratio and other estimators

A review: Solar cell current scenario and future trends

In recent years solar cell technology has achieved tremendous growth as sustainable source of energy. In last few years photovoltaic industries have emerged with an annual growth of 40%.Solar cells are renewable pollution free source of electrical energy which can easily replace traditional fossil fuels. In this article we have reviewed the previous and current status of various generations of solar cells and discussed about their future trends and aspects.&nbsp

Research and development work on substitute electrical resistance alloys for heating elements

From the start of the Second Five- Year Plan great emphasis has been laid on production and utilisation of electric power in various industrial and domestic appliances. Electric heating is thus gradually repla- cing solid-fuels, gas and oil heating . Increasing application of electric heat with all its attendant advantages will fail to register full impact unless suitable electrical heating elements , having long high temperature service life are indigenously avai- lable at reasonable cost

Confusing Sterile Neutrinos with Deviation from Tribimaximal Mixing at Neutrino Telescopes

We expound the impact of extra sterile species on the ultra high energy neutrino fluxes in neutrino telescopes. We use three types of well-known flux ratios and compare the values of these flux ratios in presence of sterile neutrinos, with those predicted by deviation from the tribimaximal mixing scheme. We show that in the upcoming neutrino telescopes, its easy to confuse between the signature of sterile neutrinos with that of the deviation from tribimaximal mixing. We also show that if the measured flux ratios acquire a value well outside the range predicted by the standard scenario with three active neutrinos only, it might be possible to tell the presence of extra sterile neutrinos by observing ultra high energy neutrinos in future neutrino telescopes.Comment: 22 pages, version to appear in Phys. Rev.

Influence of backward-facing step on the mixing efficiency of multi microjets at supersonic flow

© 2020 IAA The injection of the fuel is a highly important process for the enhancement of the scramjets. In this article, the presence of the backward-facing step on the mixing of the multi-fuel jets is expansively studied. The primary attention of this article is to scrutinize the flow feature of the fuel jet under the backward-facing step. The mixing mechanism of the fuel is also studied to compare this injection system with conventional methods. To do this, a 3-dimensional model is chosen to consider the real physic of the problem. Reynolds Average Navier-Stocks equations are solved with a computational fluid dynamic method to visualize the flow pattern of the fuel jet at the free stream Mach number of 4. SST turbulence model is also used for the calculation of the viscosity. Our results indicate that increasing the jet space from 4 to 10 times of jet diameter in the presence of the backward-facing step increases the mixing efficiency up to 20% in the downstream. Our findings depict that augmenting the number of fuel injectors from 4 to 8 augments the mixing rate up to 15% inside the combustor

On the Mass Eigenstate Composition of the 8B Neutrinos from the Sun

The present data of gallium experiments provide indirectly the only experimental limit on the fraction of $\nu_2$ mass eigenstate for the $^8$B neutrinos from the Sun. However, if to use the experimental data alone, the fraction of $\nu_2$ and, consequently, $sin^2\theta_{sol}$ still is allowed to be varied within a rather broad range. The further experimental efforts are needed to clear this point.Comment: 13 pages, 1 figure, 1 table. Corrected version, published in JCAP04(2007)00

Three Generation Neutrino Oscillation Parameters after SNO

We examine the solar neutrino problem in the context of the realistic three neutrino mixing scenario including the SNO charged current (CC) rate. The two independent mass squared differences $\Delta m^2_{21}$ and $\Delta m^2_{31} \approx \Delta m^2_{32}$ are taken to be in the solar and atmospheric ranges respectively. We incorporate the constraints on $\Delta$m$^2_{31}$ as obtained by the SuperKamiokande atmospheric neutrino data and determine the allowed values of $\Delta m^2_{21}$, $\theta_{12}$ and $\theta_{13}$ from a combined analysis of solar and CHOOZ data. Our aim is to probe the changes in the values of the mass and mixing parameters with the inclusion of the SNO data as well as the changes in the two-generation parameter region obtained from the solar neutrino analysis with the inclusion of the third generation. We find that the inclusion of the SNO CC rate in the combined solar + CHOOZ analysis puts a more restrictive bound on $\theta_{13}$. Since the allowed values of $\theta_{13}$ are constrained to very small values by the CHOOZ experiment there is no qualitative change over the two generation allowed regions in the $\Delta m^2_{21} - \tan^2 \theta_{12}$ plane. The best-fit comes in the LMA region and no allowed area is obtained in the SMA region at 3$\sigma$ level from combined solar and CHOOZ analysis.Comment: One reference added. Version to apprear in PR

Development of substitute high temperature creep resistant alloys

HIGH temperature creep resistant super strength alloys invariably contain considerable amounts of Ni,Co,W, etc. as alloying additions, in respect of which India lacks in raw material resources. Extensive work has been carried out on development of Cr-Mn-N type austenitic steels as substitute for 18 Cr 8 Ni austenitic stainless steel and their aging behaviour have been extensively studied at the National Metallurgical Laboratory in the last decade. The present work has been initiated to further study the high temperature creep behaviour of Cr-Mn-N type austenitic steels with a view to evolving suitable compositions and heat-treatment to obtain opti-mum high temperature creep strength and rupture ducti- lity in these alloys. In this group of steel Mn and N are used as the chief austenitic stabilizers besides C