19,162 research outputs found
Constraints on neutrino decay lifetime using long-baseline charged and neutral current data
We investigate the status of a scenario involving oscillations and decay for
charged and neutral current data from the MINOS and T2K experiments. We first
present an analysis of charged current neutrino and anti-neutrino data from
MINOS in the framework of oscillation with decay and obtain a best fit for
non-zero decay parameter . The MINOS charged and neutral current data
analysis results in the best fit for ~eV, and zero decay parameter, which
corresponds to the limit for standard oscillations. Our combined MINOS and T2K
analysis reports a constraint at the 90\% confidence level for the neutrino
decay lifetime ~s/eV. This is the best limit
based only on accelerator produced neutrinos
Quantum decoherence and relaxation in neutrinos using long-baseline data
We investigate the effect of quantum decoherence and relaxation in neutrino
oscillations using MINOS and T2K data. The formalism of open quantum systems is
used to describe the interaction of a neutrino system with the environment,
where the strength of the interaction is regulated by a decoherence parameter
. We assume an energy dependence parameterized by \Gamma = \gamma_0
(E/\mbox{GeV})^n, with , and study three different scenarios. The
MINOS and T2K data present a complementary behavior, with regard to our
theoretical model, resulting in a better sensitivity for and ,
respectively. We perform a combined analysis of both experimental data and
include a reactor constraint on . The results of our
combined analyses improve significantly the previous bounds on for
, reporting an upper bound of ~GeV, at the 90\%
confidence level.Comment: Corrected typo
Plastic Deformation of 2D Crumpled Wires
When a single long piece of elastic wire is injected trough channels into a
confining two-dimensional cavity, a complex structure of hierarchical loops is
formed. In the limit of maximum packing density, these structures are described
by several scaling laws. In this paper it is investigated this packing process
but using plastic wires which give origin to completely irreversible structures
of different morphology. In particular, it is studied experimentally the
plastic deformation from circular to oblate configurations of crumpled wires,
obtained by the application of an axial strain. Among other things, it is shown
that in spite of plasticity, irreversibility, and very large deformations,
scaling is still observed.Comment: 5 pages, 6 figure
Magnetocaloric effect in manganites: metamagnetic transitions for magnetic refrigeration
We present a study of the magnetocaloric effect in La5/8-yPryCa3/8MnO3
(y=0.3) and Pr0.5Ca0.09Sr0.41MnO3 manganites. The low temperature state of both
ystems is the result of a competition between the antiferromagnetic and
ferromagnetic phases. The samples display magnetocaloric effect evidenced in an
adiabatic temperature change during a metamagnetic transition from an
antiferromagnetic to a ferromagnetic phase . As additional features,
La5/8-yPryCa3/8MnO3 exhibits phase separation characterized by the coexistence
of antiferromagnetic and ferromagnetic phases and Pr0.5Ca0.09Sr0.41MnO3
displays inverse magnetocaloric effect in which temperature decreases while
applying an external magnetic field. In both cases, a significant part of the
magnetocaloric effect appears from non-reversible processes. As the traditional
thermodynamic description of the effect usually deals with reversible
transitions, we developed an alternative way to calculate the adiabatic
temperature change in terms of the change of the relative ferromagnetic
fraction induced by magnetic field. To evaluate our model, we performed direct
measurement of the sample's adiabatic temperature change by means of a
differential thermal analysis. An excellent agreement has been obtained between
experimental and calculated data. These results show that metamagnetic
transition in manganites play an important role in the study of magnetic
refrigeration.Comment: Acepted to be published in Applied Physics Letter
Diretrizes para transferĂȘncia de tecnologia: modelo de incubação de empresas.
Diretrizes para transferĂȘncia de tecnologia; TransferĂȘncia de tecnologia; Incubação de empresas; Planos de negĂłcio e planejamento de marketing.bitstream/item/117504/1/snt-doc-02a.pd
Visible neutrino decay in the light of appearance and disappearance long-baseline experiments
FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO - CNPQCOORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL DE NĂVEL SUPERIOR - CAPESWe investigate the present constraints from MINOS and T2K experiments for the neutrino decay scenario induced by non-diagonal couplings of Majorons to neutrinos. As novelty, on top of the typical invisible decay prescription, we add the contribution of visible decay, where final products can be observed. This new effect depends on the nature of the neutrino-Majoron coupling, which can be of scalar or pseudoscalar type. Using the combination of disappearance data from MINOS and disappearance and appearance data from T2K, for normal ordering, we constrain the decay para alpha E Gamma for the heaviest neutrino, where E and are the neutrino energy and width, respectively. We find that when considering visible decay within appearance data, alpha < O (10(-5))eV(2), at 90% C.L., for both kinds of couplings, which is better by one order of magnitude compared to previous bounds.11129FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO - CNPQCOORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL DE NĂVEL SUPERIOR - CAPESFUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO - CNPQCOORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL DE NĂVEL SUPERIOR - CAPES014/19164-62015/20129-3311980/2013-9461147/2014-9Sem informaçãoA.M.G. and J.J.P. acknowledge funding by the Direccion de Gestion de la Investigacion at PUCP, through grant DGI-2015-3-0026. They would also like to thank S. Sanchez for discussions on the use of GENIE, as well as O.A. Diaz in the Direccion de Tecnologias de Informacion at PUCP, for implementing our code within the LEGION system. A.M.G is thankful for the Unicamp hospitality and for the support of the FAPESP funding grant 2015/20129-3. A.M.G and O.L.G.P are also thankful to the Oficina de Internacionalizacion de la Investigacion at PUCP. A.L.G. G. is supported by CAPES, and R.A.G. would like to thanks CNPq grants 461147/2014-9 and 311980/2013-9. O.L.G.P. is thankful for the PUCP hospitality and partial support under the Programa Latino Americano de Fisica (PLAF) from Brazilian Physics Society. He is also thankful for the support of FAPESP funding grant 2014/19164-6 and CNPq research fellowship 307269/2013-2 and 304715/2016-6 and partial funding from ICTP
The complex Sine-Gordon equation as a symmetry flow of the AKNS Hierarchy
It is shown how the complex sine-Gordon equation arises as a symmetry flow of
the AKNS hierarchy. The AKNS hierarchy is extended by the ``negative'' symmetry
flows forming the Borel loop algebra. The complex sine-Gordon and the vector
Nonlinear Schrodinger equations appear as lowest negative and second positive
flows within the extended hierarchy. This is fully analogous to the well-known
connection between the sine-Gordon and mKdV equations within the extended mKdV
hierarchy.
A general formalism for a Toda-like symmetry occupying the ``negative''
sector of sl(N) constrained KP hierarchy and giving rise to the negative Borel
sl(N) loop algebra is indicated.Comment: 8 pages, LaTeX, typos corrected, references update
Integrable Field Theories with Defects
The structure of integrable field theories in the presence of defects is
discussed in terms of boundary functions under the Lagrangian formalism.
Explicit examples of bosonic and fermionic theories are considered. In
particular, the boundary functions for the super sinh-Gordon model is
constructed and shown to generate the Backlund transformations for its soliton
solutions.Comment: talk presented at the XVth International Colloquium on Integrable
Systems and Quantum Symmetries, to appear in Czechoslovak Journal of Physics
(2006
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