24,444 research outputs found
Generalised CP and Family Symmetry
We perform a comprehensive study of the family symmetry
combined with the generalised CP symmetry . We investigate the
lepton mixing parameters which can be obtained from the original symmetry
breaking to different remnant symmetries in
the neutrino and charged lepton sectors, namely and subgroups
in the neutrino and the charged lepton sector respectively, and the remnant CP
symmetries from the breaking of are and
, respectively, where all cases correspond to a preserved
symmetry smaller than the full Klein symmetry, as in the semi-direct approach,
leading to predictions which depend on a single undetermined real parameter,
which may be fitted to the reactor angle for example. We discuss 26 possible
cases, including a global determination of the best fit parameters and
the correlations between mixing parameters, in each case.Comment: 71 pages, 10 figure
Physico-chemical factors and bacteria in fish ponds
Analyses of pond water and mud samples show that nitrifying bacteria (including ammonifying bacteria, nitrite bacteria, nitrobacteria and denitrifying bacteria) are in general closely correlated with various physico-chemical factors, ammonifying bacteria are mainly correlated with dissolved oxygen; denitrifying bacteria are inversely correlated with phosphorus; nitrite bacteria are closely correlated with nitrites, nitrobacteria are inversely correlated with ammoniac nitrogen. The nitrifying bacteria are more closely correlated with heterotrophic bacteria. Nitrobacteria are inversely correlated with anaerobic heterotrophic bacteria. The correlation is quite weak between all the nitrite bacteria which indicates that the nitrite bacteria have a controlling and regulating function in water quality and there is no interdependence as each plays a role of its own. The paper also discusses how the superficial soil (pond mud down to 3.5 cm deep) and different layers of the mud affect the biomass of bacteria. The study shows that the top superficial layer (down to 1.5 cm deep) is the major area for decomposing and converting organic matter
The decay of the and its nature as a molecule
We investigate the decay of with the assumption
that the is dynamically generated from the
interaction. In addition to the tree level diagrams that proceed via , we take into account also the final
state interactions of and . The
partial decay width and mass distributions of are
evaluated. We get a value for the partial decay width which, within errors, is
in fair agreement with the experimental result. The contribution from the tree
level diagrams is dominant, but the final state interactions have effects in
the mass distributions. The predicted mass distributions are significantly
different from phase space and tied to the nature of the
state.Comment: Published versio
Two ultracold atoms in a completely anisotropic trap
As a limiting case of ultracold atoms trapped in deep optical lattices, we
consider two interacting atoms trapped in a general anisotropic harmonic
oscillator potential, and obtain exact solutions of the Schrodinger equation
for this system. The energy spectra for different geometries of the trapping
potential are compared.Comment: 4 pages, 2 figure
Leptogenesis and residual CP symmetry
We discuss flavour dependent leptogenesis in the framework of lepton flavour
models based on discrete flavour and CP symmetries applied to the type-I seesaw
model. Working in the flavour basis, we analyse the case of two general
residual CP symmetries in the neutrino sector, which corresponds to all
possible semi-direct models based on a preserved in the neutrino sector,
together with a CP symmetry, which constrains the PMNS matrix up to a single
free parameter which may be fixed by the reactor angle. We systematically study
and classify this case for all possible residual CP symmetries, and show that
the -matrix is tightly constrained up to a single free parameter, with only
certain forms being consistent with successful leptogenesis, leading to
possible connections between leptogenesis and PMNS parameters. The formalism is
completely general in the sense that the two residual CP symmetries could
result from any high energy discrete flavour theory which respects any CP
symmetry. As a simple example, we apply the formalism to a high energy
flavour symmetry with a generalized CP symmetry, broken to two residual CP
symmetries in the neutrino sector, recovering familiar results for PMNS
predictions, together with new results for flavour dependent leptogenesis.Comment: 35 pages, 8 figure
A loop group method for minimal surfaces in the three-dimensional Heisenberg group
We characterize constant mean curvature surfaces in the three-dimensional
Heisenberg group by a family of flat connections on the trivial bundle \D
\times \GL over a simply connected domain in the complex plane.
In particular for minimal surfaces, we give an immersion formula, the so-called
Sym-formula, and a generalized Weierstrass type representation via the loop
group method.Comment: 40 pages, v2: The argument for branch points has been fixed and the
references have been updated. v3: The argument for canonical examples has
been fixed and the classification for homogeneous surfaces has been added v4:
Some typos are fixed and Remark 5.4 (3) is adde
- …