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

Non-classical photon pair generation in atomic vapours

A scheme for the generation of non-classical pairs of photons in atomic vapours is proposed. The scheme exploits the fact that the cross correlation of the emission of photons from the extreme transitions of a four-level cascade system shows anti-bunching which has not been reported earlier and which is unlike the case of the three level cascade emission which shows bunching. The Cauchy-Schwarz inequality which is the ratio of cross-correlation to the auto correlation function in this case is estimated to be $10^3-10^6$ for controllable time delay, and is one to four orders of magnitude larger compared to previous experiments. The choice of Doppler free geometry in addition to the fact that at three photon resonance the excitation/deexcitation processes occur in a very narrow frequency band, ensures cleaner signals.Comment: 18 pages, 7 figure

Transesterification of Waste Cooking Oil Catalysed by Crystalline Copper Doped Zinc Oxide Nanocatalyst

Biodiesel has its unique position in the field of renewable energy as alternate fuel to diesel due to fuel price, energy requirement and petroleum crisis. In this study, biodiesel was produced from Waste Cooking Oil (WCO) using Copper doped Zinc Oxide (CZO) nanocatalysts. The synthesized Copper doped Zinc Oxide nanocatalysts were characterized by X-Ray Diffraction (XRD) and High Resolution Transmission Electron Microscope (HRTEM). Design of experiment was framed using Taguchi method to limit the experiments and to find the optimum reaction conditions. The effect of process parameters such as oil-to-methanol ratio (O/M), catalyst type, catalyst concentration, temperature and time on the transesterification reactions using characterized Copper doped Zinc Oxide nanocatalyst were investigated. The 4% (weight /weight) nanocatalyst concentration, 1:5 Oil to methanol molar ratio at 60°C temperature and 40 minutes of reaction time were found to be optimum, in which the maximum biodiesel yield of 98 % (w/w) was obtained. Hence it was determined that nanocatalysts exhibited good catalytic activities on biodiesel production from Waste Cooking Oil (WCO)

Transesterification of Waste Cooking Oil Catalysed by Crystalline Copper Doped Zinc Oxide Nanocatalyst

Biodiesel has its unique position in the field of renewable energy as alternate fuel to diesel due to fuel price, energy requirement and petroleum crisis. In this study, biodiesel was produced from Waste Cooking Oil (WCO) using Copper doped Zinc Oxide (CZO) nanocatalysts. The synthesized Copper doped Zinc Oxide nanocatalysts were characterized by X-Ray Diffraction (XRD) and High Resolution Transmission Electron Microscope (HRTEM). Design of experiment was framed using Taguchi method to limit the experiments and to find the optimum reaction conditions. The effect of process parameters such as oil-to-methanol ratio (O/M), catalyst type, catalyst concentration, temperature and time on the transesterification reactions using characterized Copper doped Zinc Oxide nanocatalyst were investigated. The 4% (weight /weight) nanocatalyst concentration, 1:5 Oil to methanol molar ratio at 60°C temperature and 40 minutes of reaction time were found to be optimum, in which the maximum biodiesel yield of 98 % (w/w) was obtained. Hence it was determined that nanocatalysts exhibited good catalytic activities on biodiesel production from Waste Cooking Oil (WCO)