118940895
"Bimaximal + Democratic"type neutrino mass matrix in view of quark-lepton complementarity
We demonstrate that `Bimaximal + Democratic' type neutrino mass matrix can accommodate the deviation of $\theta_\odot$ from its maximal value which referred in the literature as `quark-lepton complementarity' along with the other present day neutrino experimental results, namely, atmospheric, CHOOZ, neutrinoless double beta decay ($\beta\beta_{0\nu}$) and result obtained from WMAP experiment. We define a function $\chi_p$ in terms of solar and atmospheric neutrino mass squared differences and solar neutrino mixing angle (obtained from different experiments and our proposed texture). The masses and mixing angles are expressed in terms of three parameters in our proposed texture. The allowed region of the texture parameters is obtained through minimization of the above function. The proposed texture crucially depends on the value of the experimental results of $\beta\beta_{0\nu}$ experiment among all other above mentioned experiments. If, in future, $\beta\beta_{0\nu}$ experiments, namely, MOON, EXO, GENIUS shift the lower bound on $$ at the higher side by one order, the present texture will be ruled out.
126402826
Extension of Minimal Fermionic Dark Matter Model
15935653
Effect of flavour oscillations on the detection of supernova neutrinos
Neutrinos and antineutrinos of all three flavours are emitted during the post-bounce phase of a core-collapse supernova with having average energies more than that of They can be detected by the new earthbound detectors like SNO and Super-Kamiokande which are sensitive to neutrinos of all three flavours. In this letter we consider the effect of flavour oscillations on the neutrino flux and their expected number of events at the detector. We do a three-generation analysis and for the mass and mixing schemes we first consider the threefold maximal mixing model consistent with the solar and the atmospheric neutrino data and next a scenario with one m2~10-11 eV2 (solar range) and the other m2~10-18 eV2, for which the oscillation length is of the order of the supernova distance. In both these scenarios there are no matter effects in the resultant neutrino spectrum and one is concerned with vacuum oscillations. We find that though neutrino oscillations result in a depletion in the number of e and coming from the supernova, the actual signals at the detectors are appreciable enhanced as the e and energy spectra become harder.
46702702
A possible explanation of low energy γ-ray excess from galactic centre and Fermi bubble by a Dark Matter model with two real scalars
We promote the idea of multi-component Dark Matter (DM) to explain results from both direct and indirect detection experiments. In these models as contribution of each DM candidate to relic abundance is summed up to meet WMAP/Planck measurements of Ω{sub DM}, these candidates have larger annihilation cross-sections compared to the single-component DM models. We illustrate this fact by introducing an extra scalar to the popular single real scalar DM model. We also present detailed calculations for the vacuum stability bounds, perturbative unitarity and triviality constraints on this model. As direct detection experimental results still show some conflict, we kept our options open, discussing different scenarios with different DM mass zones. In the framework of our model we make an interesting observation: the existing direct detection experiments like CDMS II, CoGeNT, CRESST II, XENON 100 or LUX together with the observation of excess low energy γ-ray from galactic centre and Fermi bubble by Fermi Gamma-ray Space Telescope (FGST) already have the capability to distinguish between different DM halo profiles.
118455395
Quintom scalar field : Varying dark energy equation of state obtained from recent SNe Ia, BAO and OHD data
From the analysis of Supernova Ia data alongwith Observational Hubble Data (OHD) and Baryon Acoustic Oscillation (BAO) data, we attempt to find out the nature of a scalar potential that may be responsible for the Dark Energy of the universe. We demonstrate that in order to explain the varying dark energy equation of state ($\omega_X(z)$) as obtained in a model independent way from the analyses of observational data, we need to invoke a quintom scalar field having a "quintessence" part for $\omega_X(z) > -1$ and a "phantom" part for $\omega_X(z) < -1$. We consider a Gaussian type potential for these scalar fields and compare the dark energy equation of state derived from such potential with the one computed from the data analysis.
17989564
Dark Matter -- Possible Candidates and Direct Detection
The cosmological observations coupled with theoretical calculations suggest the existence of enormous amount of unseen and unknown matter or dark matter in the universe. The evidence of their existence, the possible candidates and their possible direct detections are discussed.
121757164
Energy dependence of mean square charged multiplicity in Regge--Mueller formalism
Abstract The energy dependence of the mean square multiplicity is obtained on the basis of a Regge-Mueller analysis, when a pomeron with α p(0) = 1 and subsidiary trajectories with α(0) = 1 2 are present. The expression for 〈 n ( n − 1)〉 is shown to be of the form c 1 (ln s ) 2 + c 2 (ln s ) + c 3 + c 4 (ln s ) 2 /√ s + c 5 ln s /√ s + c 6 /√ s , with the coefficients given in terms of certain well defined integrals over physically measurable quantities. We are unable, with available experimental data on inclusive reations to estimate all these coefficients. However, retaining only the terms that survive as s →∞, we obtain a simple expression for the correlation function f 2 = 〈 n ( n −1)〉 − 〈 n 〉 2 for which a reasonable estimate has been made. The agreement with experiment is good.
121251309
SOME QUARK--PARTON-MODEL INEQUALITIES FOR THE NEUTRON AND PROTON INELASTIC STRUCTURE FUNCTIONS.
120089980
ELECTROMAGNETIC MASS DIFFERENCES.
Abstract In Cottingham's approach to electromagnetic masses ( δm ) one encounters the problem of unknown subtractions in the fixed mass dispersion relations for the virtual Compton scattering amplitude. We avoid this problem and express δm in terms of measurable quantities, assuming knowledge of light-cone singularities of the electro-magnetic current commutator.
121043964
INELASTIC e--p SCATTERING DATA AND A NEW PARTON MODEL.
119974277
Inelastic-Compton-Scattering Inequalities in the Quark-Parton Model