119243959
Lower bound on neutrino mass and possible CP violation in neutrino oscillations
The phenomenology of the most general lepton mass matrices obtained through weak basis transformations has been discussed. Using a hierarchical parametrization of these mass matrices, the exact relations for lepton mixing angles have been obtained assuming normal neutrino mass hierarchy and natural structures of lepton mass matrices. The recent three neutrino oscillation data together with the condition of naturalness on Dirac lepton mass matrices provide a lower bound on the lightest neutrino mass of m{\nu}1 > 3 meV along with a non-vanishing Dirac CP violating phase.
118676024
Generic lepton mass matrices and neutrino oscillations
Several intriguing aspects of neutrino oscillation phenomenology like the origin of small neutrino masses, the absolute neutrino mass scale, the neutrino mass hierarchy, i.e. normal or inverted and the nature of neutrinos, i.e. Dirac or Majorana, etc. have been addressed from a general perspective. We show how the fundamental considerations of unitary transformations, naturalness and seesaw mechanism suffices to determine the texture structure of fermion Yukawa couplings and discuss the significance of the effective mass in 0{\nu}{\beta}{\beta} decay for the texture structure of these couplings.
119290519
Minimal weak basis textures and quark mixing data
The phenomenology of the most general quark mass matrices with a minimum of three texture zeros obtained through weak basis (WB) transformations has been discussed within the framework of the standard model. The relationship between the textures, naturalness and WB transformations has also been studied. Adopting a ?hierarchical? parameterization for the quark mass matrix, we have detailed exact relations for the various elements of the quark mixing matrix along with the CP asymmetry angle ?, illustrating the?explicit relationship between the observed hierarchies among the WB quark mass matrices and the quark mixing matrix. Besides exploring the complete parameter space available to the (Mq)11, (q = u, d) elements in these mass matrices, their implications for quark mixing data and CP violation asymmetries have also been explored.
17250672
Implications of CP asymmetry parameter sin2β on structural features of texture specific mass matrices
Abstract In the context of Fritzsch-like texture 4 zero Hermitian quark mass matrices, we have attempted to find an ‘exact’ formula for sin 2 β wherein the dependence of β on the quark masses and the elements of the quark mass matrices is visible in a simple and clear manner. This has been achieved keeping in mind the strong hierarchy of the quark masses and assuming the weak hierarchy amongst the elements of the mass matrices. This ‘exact’ formula represents a vast improvement over the leading order formula based on strong hierarchy of the elements of the mass matrices. Apart from showing the compatibility of texture 4 zero mass matrices with the present value of sin 2 β and other CKM parameters, we find interesting conclusions regarding the structural features of the mass matrices.
15979251
Texture specific mass matrices with Dirac neutrinos and their implications
Considering Dirac neutrinos and Fritzsch-like texture six zero and five zero mass matrices, detailed predictions for cases pertaining to normal/inverted hierarchy as well as degenerate scenario of neutrino masses have been carried out. All the cases considered here pertaining to inverted hierarchy and degenerate scenario of neutrino masses are ruled out by the existing data. For the normal hierarchy cases, the lower limit of m{sub {nu}{sub 1}} and of s{sub 13} as well as the range of Dirac-like CP violating phase {delta}{sub l} would have implications for the texture specific cases considered here.
118456219
Lepton textures and neutrino oscillations
A systematic analysis of the textures arising in lepton mass matrices have been carried out using unitary transformations and condition of naturalness for the Dirac and Majorana neutrino possibilities. It is observed that the recent three neutrino oscillation data together with the effective mass in neutrinoless double beta decay provide vital clues in predicting the general structures of these lepton mass matrices.
123187586
Anomalous magnetic moments for uncharmed and charmed baryons
We studied anomalous magnetic moments of the baryons using Drell–Hearn sum rules and found that the observed moments agree better in the presence of symmetry breaking effects.
122779562
Charm Changing Radiative Weak Decays in AFS Model
119505534
Why the proton-neutron moment ratio is -1.46
Using the pion-cloud model of nucleons, the author finds that the observed ratio mu (p)/ mu (n) can be explained in the presence of core contributions to the nucleon moments.
122409884
Baryon masses in broken SU(8)
We demonstrate that the mass relations among 1/2/sup +/ baryons predicted in quark models can be obtained in SU(8) symmetry, by adding higher-order effects or by including spin-triplet mass breaking. The masses of 3/2/sup +/ isobars are also discussed.
121723426
Higher-order mass formulas in SU(4)
We derive mass formulas among hadrons (1/2/sup +/,3/2/sup +/,O/sup -/,1/sup -/) in SU(4) framework including second-order mass contributions from 84 and 20'' representations. Some hybrid mass relations are obtained by relating second-order parameters. masses of some hadrons are estimated.