11,463 research outputs found
Probing neutrino transition magnetic moments with coherent elastic neutrino-nucleus scattering
We explore the potential of current and next generation of coherent elastic
neutrino-nucleus scattering (CENS) experiments in probing neutrino
electromagnetic interactions. On the basis of a thorough statistical analysis,
we determine the sensitivities on each component of the Majorana neutrino
transition magnetic moment (TMM), , that
follow from low-energy neutrino-nucleus experiments. We derive the sensitivity
to neutrino TMM from the first CENS measurement by the COHERENT
experiment, at the Spallation Neutron Source. We also present results for the
next phases of COHERENT using HPGe, LAr and NaI[Tl] detectors and for reactor
neutrino experiments such as CONUS, CONNIE, MINER, TEXONO and RED100. The role
of the CP violating phases in each case is also briefly discussed. We conclude
that future CENS experiments with low-threshold capabilities can improve
current TMM limits obtained from Borexino data.Comment: 25 pages, 8 figures, 2 tables, analysis updated; conclusions
unchanged; references added; matches published versio
Systematic Study Of Leptonic Mixing In A Class Of SU_H(2) Models
We perform a systematic analysis of the PMNS matrices which arise when one
assigns the three generations of leptons to the representation of a
horizontal symmetry. This idea has been previously explored by
Kuchimanchi and Mohapatra. However, we assume the neutrino mass matrix
results from leptonic couplings to triplet scalar fields and
hierarchies exist amongst lepton mass matrix elements which result from
couplings to scalar fields with different charges. Of the sixteen
candidate PMNS matrices which result it is found that only one is both
predictive and possesses a leading order structure compatible with experimental
data. The relevant neutrino mass matrix displays the symmetry
to leading order and we explore the perturbations required
to produce a realistic lepton spectrum. The effective mass in neutrinoless
double beta decay is required to lie in the range
, which is just below current
experimental bounds. is non-zero but not uniquely determined.Comment: To appear in Phys. Rev.
On q-Deformed Supersymmetric Classical Mechanical Models
Based on the idea of quantum groups and paragrassmann variables, we presenta
generalization of supersymmetric classical mechanics with a deformation
parameter dealing with the case. The
coordinates of the -superspace are a commuting parameter and a
paragrassmann variable , where . The generator and
covariant derivative are obtained, as well as the action for some possible
superfields.Comment: No figures, 14 pages, Latex, revised versio
Implications of the first detection of coherent elastic neutrino-nucleus scattering (CEvNS) with Liquid Argon
The CENNS-10 experiment of the COHERENT collaboration has recently reported
the first detection of coherent-elastic neutrino-nucleus scattering (CEvNS) in
liquid Argon with more than significance. In this work, we exploit
the new data in order to probe various interesting parameters which are of key
importance to CEvNS within and beyond the Standard Model. A dedicated
statistical analysis of these data shows that the current constraints are
significantly improved in most cases. We derive a first measurement of the
neutron rms charge radius of Argon, and also an improved determination of the
weak mixing angle in the low energy regime. We also update the constraints on
neutrino non-standard interactions, electromagnetic properties and light
mediators with respect to those derived from the first COHERENT-CsI data.Comment: discussion expanded including light mediators and nuclear
uncertainties, figures added, references added. V3: Fig. 7 corrected,
conclusions unchange
Quasi Harmonic Lattice Dynamics and Molecular Dynamics calculations for the Lennard-Jones solids
We present Molecular Dynamics (MD), Quasi Harmonic Lattice Dynamics (QHLD)
and Energy Minimization (EM) calculations for the crystal structure of Ne, Ar,
Kr and Xe as a function of pressure and temperature. New Lennard-Jones (LJ)
parameters are obtained for Ne, Kr and Xe to reproduce the experimental
pressure dependence of the density. We employ a simple method which combines
results of QHLD and MD calculations to achieve densities in good agreement with
experiment from 0 K to melting. Melting is discussed in connection with
intrinsic instability of the solid as given by the QHLD approximation. (See
http://www.fci.unibo.it/~valle for related papers)Comment: 7 pages, 5 figures, REVte
An extension of SPARQL for expressing qualitative preferences
In this paper we present SPREFQL, an extension of the SPARQL language that
allows appending a PREFER clause that expresses "soft" preferences over the
query results obtained by the main body of the query. The extension does not
add expressivity and any SPREFQL query can be transformed to an equivalent
standard SPARQL query. However, clearly separating preferences from the "hard"
patterns and filters in the WHERE clause gives queries where the intention of
the client is more cleanly expressed, an advantage for both human readability
and machine optimization. In the paper we formally define the syntax and the
semantics of the extension and we also provide empirical evidence that
optimizations specific to SPREFQL improve run-time efficiency by comparison to
the usually applied optimizations on the equivalent standard SPARQL query.Comment: Accepted to the 2017 International Semantic Web Conference, Vienna,
October 201
Emitters of -photon bundles
We propose a scheme based on the coherent excitation of a two-level system in
a cavity to generate an ultrabright CW and focused source of quantum light that
comes in groups (bundles) of photons, for an integer tunable with the
frequency of the exciting laser. We define a new quantity, the \emph{purity} of
-photon emission, to describe the percentage of photons emitted in bundles,
thus bypassing the limitations of Glauber correlation functions. We focus on
the case and show that close to 100% of two-photon emission and
90% of three-photon emission is within reach of state of the art cavity QED
samples. The statistics of the bundles emission shows that various
regimes---from -photon lasing to -photon guns---can be realized. This is
evidenced through generalized correlation functions that extend the standard
definitions to the multi-photon level.Comment: Introduce the n-th order N-photon correlation functions. Reorganized
to emphasize the N-photon emitter, now extended to the antibunching regime,
rather than only coherent emission as previsoul
Neutrino Unification
Present neutrino data are consistent with neutrino masses arising from a
common seed at some ``neutrino unification'' scale . Such a simple
theoretical ansatz naturally leads to quasi-degenerate neutrinos that could lie
in the electron-volt range with neutrino mass splittings induced by
renormalization effects associated with supersymmetric thresholds. In such a
scheme the leptonic analogue of the Cabibbo angle describing
solar neutrino oscillations is nearly maximal. Its exact value is correlated
with the smallness of . These features agree both with latest
data on the solar neutrino spectra and with the reactor neutrino data. The two
leading mass-eigenstate neutrinos present in \ne form a pseudo-Dirac neutrino,
avoiding conflict with neutrinoless double beta decay.Comment: RevTex format, 2 figures, 4 pages, a few new references, no other
important change, figures unchanged, version to be published in PR
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