22,871 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
Disagreement between capture probabilities extracted from capture and quasi-elastic backscattering excitation functions
Experimental quasi-elastic backscattering and capture (fusion) excitation
functions are usually used to extract the s-wave capture probabilities for the
heavy-ion reactions. We investigated the
O+Sn,Sm,Pb systems at energies near and below
the corresponding Coulomb barriers and concluded that the probabilities
extracted from quasi-elastic data are much larger than the ones extracted from
fusion excitation functions at sub and deep-sub barrier energies. This seems to
be a reasonable explanation for the known disagreement observed in literature
for the nuclear potential diffuseness derived from both methods.Comment: 9 pages, 3 figure
Supersymmetric Extension of the Quantum Spherical Model
In this work, we present a supersymmetric extension of the quantum spherical
model, both in components and also in the superspace formalisms. We find the
solution for short/long range interactions through the imaginary time formalism
path integral approach. The existence of critical points (classical and
quantum) is analyzed and the corresponding critical dimensions are determined.Comment: 21 pages, fixed notation to match published versio
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
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