744 research outputs found
Solar Neutrino Oscillation Parameters after KamLAND
We explore the impact of the data from the KamLAND experiment in constraining
neutrino mass and mixing angles involved in solar neutrino oscillations. In
particular we discuss the precision with which we can determine the the mass
squared difference and the mixing angle
from combined solar and KamLAND data. We show that the precision with which
\Delta m^_{solar} can be determined improves drastically with the KamLAND
data but the sensitivity of KamLAND to the mixing angle is not as good. We
study the effect of enhanced statistics in KamLAND as well as reduced
systematics in improving the precision. We also show the effect of the SNO salt
data in improving the precision. Finally we discuss how a dedicated reactor
experiment with a baseline of 70 km can improve the
sensitivity by a large amount.Comment: Talk given at 4th International Conference on Nonaccelerator New
Physics (NANP 03), Dubna, Russia, 23-28 Jun 200
Lepton Masses in a Minimal Model with Triplet Higgs Bosons and Flavor Symmetry
Viable neutrino and charged lepton masses and mixings are obtained by
imposing a flavor symmetry in a model with a few
additional Higgs. We use two triplet Higgs which are arranged as a
doublet of , and standard model singlet Higgs which are also put as
doublets of . We break the 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 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 and zero .
We allow for a mild breaking of the symmetry for the neutrinos and
study the phenomenology. We give predictions for and the CP
violating Jarlskog invariant , as a function of the 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
Interpretation of scanning tunneling quasiparticle interference and impurity states in cuprates
We apply a recently developed method combining first principles based Wannier
functions with solutions to the Bogoliubov-de Gennes equations to the problem
of interpreting STM data in cuprate superconductors. We show that the observed
images of Zn on the surface of BiSrCaCuO can only be understood
by accounting for the tails of the Cu Wannier functions, which include
significant weight on apical O sites in neighboring unit cells. This
calculation thus puts earlier crude "filter" theories on a microscopic
foundation and solves a long standing puzzle. We then study quasiparticle
interference phenomena induced by out-of-plane weak potential scatterers, and
show how patterns long observed in cuprates can be understood in terms of the
interference of Wannier functions above the surface. Our results show excellent
agreement with experiment and enable a better understanding of novel phenomena
in the cuprates via STM imaging.Comment: 5 pages, 5 figures, published version (Supplemental Material: 5
pages, 11 figures) for associated video file, see
http://itp.uni-frankfurt.de/~kreisel/QPI_BSCCO_BdG_p_W.mp
Neutrino parameters from matter effects in at long baselines
We show that the earth matter effects in the
survival probability can be used to cleanly determine the third leptonic mixing
angle and the sign of the atmospheric neutrino mass squared
difference, , using a -beam as a source.Comment: 4 pages, 4 eps figures; comments and references added, to appear in
Phys. Rev.
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. 
Recurrence recovery in heterogeneous Fermi--Pasta--Ulam--Tsingou systems
The computational investigation of Fermi, Pasta, Ulam, and Tsingou of arrays
of nonlinearly coupled oscillators has led to a wealth of studies in nonlinear
dynamics. Most studies of oscillator arrays have considered homogeneous
oscillators, even though there are inherent heterogeneities between
{individual} oscillators in real-world arrays. Well-known FPUT phenomena, such
as energy recurrence, can break down in such heterogeneous systems. In this
paper, we present an approach -- the use of structured heterogeneities -- to
recover recurrence in FPUT systems in the presence of oscillator
heterogeneities. We examine oscillator variabilities in FPUT systems with cubic
nonlinearities, and we demonstrate that centrosymmetry in oscillator arrays may
be an important source of recurrence.Comment: revised versio
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 mass eigenstate for the B
neutrinos from the Sun. However, if to use the experimental data alone, the
fraction of and, consequently, 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
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