1,883 research outputs found
MiniBooNE and a (CP)^2 = -1 sterile neutrino
It has been taken as granted that the observation of two independent
mass-squared differences necessarily fixes the number of underlying mass
eigenstates as three, and that the addition of a sterile neutrino provides an
additional mass-squared difference. The purpose of this Letter is to argue that
if one considers a sterile neutrino component that belongs to the (CP)^2 = - 1
sector, then both of the stated claims are false. We also outline how the
results reported here, when combined with the forthcoming MiniBooNE data and
other experiments, can help settle the issue of the CP properties of the
sterile neutrino; if such a component does indeed exist.Comment: Mod. Phys. Lett. A (in press, 8 pages
Neutrino oscillations with disentanglement of a neutrino from its partners
We bring attention to the fact that in order to understand existing data on
neutrino oscillations, and to design future experiments, it is imperative to
appreciate the role of quantum entanglement. Once this is accounted for, the
resulting energy-momentum conserving phenomenology requires a single new
parameter related to disentanglement of a neutrino from its partners. This
parameter may not be CP symmetric. We illustrate the new ideas, with
potentially measurable effects, in the context of a novel experiment recently
proposed by Gavrin, Gorbachev, Veretenkin, and Cleveland. The strongest impact
of our ideas is on the resolution of various anomalies in neutrino oscillations
and on neutrino propagation in astrophysical environments.Comment: 6 page
Interplay of gravitation and linear superposition of different mass eigenstates
The interplay of gravitation and the quantum-mechanical principle of linear
superposition induces a new set of neutrino oscillation phases. These ensure
that the flavor-oscillation clocks, inherent in the phenomenon of neutrino
oscillations, redshift precisely as required by Einstein's theory of
gravitation. The physical observability of these phases in the context of the
solar neutrino anomaly, type-II supernovae, and certain atomic systems is
briefly discussed
Relatedness Measures to Aid the Transfer of Building Blocks among Multiple Tasks
Multitask Learning is a learning paradigm that deals with multiple different
tasks in parallel and transfers knowledge among them. XOF, a Learning
Classifier System using tree-based programs to encode building blocks
(meta-features), constructs and collects features with rich discriminative
information for classification tasks in an observed list. This paper seeks to
facilitate the automation of feature transferring in between tasks by utilising
the observed list. We hypothesise that the best discriminative features of a
classification task carry its characteristics. Therefore, the relatedness
between any two tasks can be estimated by comparing their most appropriate
patterns. We propose a multiple-XOF system, called mXOF, that can dynamically
adapt feature transfer among XOFs. This system utilises the observed list to
estimate the task relatedness. This method enables the automation of
transferring features. In terms of knowledge discovery, the resemblance
estimation provides insightful relations among multiple data. We experimented
mXOF on various scenarios, e.g. representative Hierarchical Boolean problems,
classification of distinct classes in the UCI Zoo dataset, and unrelated tasks,
to validate its abilities of automatic knowledge-transfer and estimating task
relatedness. Results show that mXOF can estimate the relatedness reasonably
between multiple tasks to aid the learning performance with the dynamic feature
transferring.Comment: accepted by The Genetic and Evolutionary Computation Conference
(GECCO 2020
Exotic Low Density Fermion States in the Two Measures Field Theory: Neutrino Dark Energy
We study a new field theory effect in the cosmological context in the Two
Measures Field Theory (TMT). TMT is an alternative gravity and matter field
theory where the gravitational interaction of fermionic matter is reduced to
that of General Relativity when the energy density of the fermion matter is
much larger than the dark energy density. In this case also the 5-th force
problem is solved automatically. In the opposite limit, where the magnitudes of
fermionic energy density and scalar field dark energy density become
comparable, nonrelativistic fermions can participate in the cosmological
expansion in a very unusual manner. Some of the features of such states in a
toy model of the late time universe filled with homogeneous scalar field and
uniformly distributed nonrelativistic neutrinos: neutrino mass increases as m ~
a^{3/2}; the neutrino gas equation-of-state approaches w=-1, i.e. neutrinos
behave as a sort of dark energy; the total (scalar field + neutrino)
equation-of-state also approaches w=-1; the total energy density of such
universe is less than it would be in the universe filled with the scalar field
alone. An analytic solution is presented. A domain structure of the dark energy
seems to be possible. We speculate that decays of the CLEP state neutrinos may
be both an origin of cosmic rays and responsible for a late super-acceleration
of the universe. In this sense the CLEP states exhibit simultaneously new
physics at very low densities and for very high particle masses.Comment: 47 pages, accepted for publication in Int.J.Mod.Phys.
Majorana-Like (j,0)+(0,j) Representation Spaces: Construction and Physical Interpretation
We present a formalism that extends the Majorana-construction to arbitrary
spin (j,0)+(0,j) representation spaces. For the example case of spin-1, a wave
equation satisfied by the Majorana-like (1,0)+(0,1) spinors is constructed and
its physical content explored. The (j,0)+(0,j) Majorana-construct is found to
possess an unusual classical and quantum field theoretic structure. Relevance
of our formalism to parity violation, hadronic phenomenologies, and grand
unified field theories is briefly pointed out.Comment: Replaced because some people were having trouble TeXing the old
version. No changes implemente
The quadratic spinor Lagrangian, axial torsion current, and generalizations
We show that the Einstein-Hilbert, the Einstein-Palatini, and the Holst
actions can be derived from the Quadratic Spinor Lagrangian (QSL), when the
three classes of Dirac spinor fields, under Lounesto spinor field
classification, are considered. To each one of these classes, there corresponds
a unique kind of action for a covariant gravity theory. In other words, it is
shown to exist a one-to-one correspondence between the three classes of
non-equivalent solutions of the Dirac equation, and Einstein-Hilbert,
Einstein-Palatini, and Holst actions. Furthermore, it arises naturally, from
Lounesto spinor field classification, that any other class of spinor field
(Weyl, Majorana, flagpole, or flag-dipole spinor fields) yields a trivial
(zero) QSL, up to a boundary term. To investigate this boundary term we do not
impose any constraint on the Dirac spinor field, and consequently we obtain new
terms in the boundary component of the QSL. In the particular case of a
teleparallel connection, an axial torsion 1-form current density is obtained.
New terms are also obtained in the corresponding Hamiltonian formalism. We then
discuss how these new terms could shed new light on more general
investigations.Comment: 9 pages, RevTeX, to be published in Int.J.Mod.Phys.D (2007
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