111 research outputs found
Neutrino Decay and Atmospheric Neutrinos
We reconsider neutrino decay as an explanation for atmospheric neutrino
observations. We show that if the mass-difference relevant to the two mixed
states \nu_\mu and \nu_\tau is very small (< 10^{-4} eV^2), then a very good
fit to the observations can be obtained with decay of a component of \nu_\mu to
a sterile neutrino and a Majoron. We discuss how the K2K and MINOS
long-baseline experiments can distinguish the decay and oscillation scenarios.Comment: 9 pages, Revtex, uses epsf.sty, 3 postscript figures. Additions and
corrections to references, minor changes in the text and to some number
Neutrino Oscillations in the Early Universe with Nonequilibrium Neutrino Distributions
Around one second after the big bang, neutrino decoupling and -
annihilation distort the Fermi-Dirac spectrum of neutrino energies. Assuming
neutrinos have masses and can mix, we compute the distortions using
nonequilibrium thermodynamics and the Boltzmann equation. The flavor behavior
of neutrinos is studied during and following the generation of the distortion.Comment: accepted for publication in Physical Review
One pion events by atmospheric neutrinos: A three flavor analysis
We study the one-pion events produced via neutral current (NC) and charged
current (CC) interactions by the atmospheric neutrinos. We analyze the ratios
of these events in the framework of oscillations between three neutrino
flavors. The ratios of the CC events induced by to that of the NC
events and a similar ratio defined with help us in distinguishing the
different regions of the neutrino parameter space.Comment: 14 pages, 4 figures (separate postscript files
T-violation tests for relativity principles
We consider the implications of a violation of the equivalence principle or
of Lorentz invariance in the neutrino sector for the T-asymmetry in a
three-flavour framework. We find that additional mixing due to these
mechanisms, while obeying all present bounds, can lead to a substantial
enhancement, suppression, and/or sign change in for the preferred
energies and baselines of a neutrino factory. This in turn allows for the
possibility of improving existing constraints by several orders of magnitude.Comment: 2 pages; Talk given at the 4th NuFact '02 Workshop (Neutrino
Factories Based On Muon Storage Rings), 1-6 Jul 2002, London, England; To
appear in proceeding
On the interactions of melatonin/β-cyclodextrin inclusion complex: A novel approach combining efficient semiempirical extended tight-binding (xtb) results with ab initio methods
Melatonin (MT) is a molecule of paramount importance in all living organisms, due to its presence in many biological activities, such as circadian (sleep–wake cycle) and seasonal rhythms (reproduction, fattening, molting, etc.). Unfortunately, it suffers from poor solubility and, to be used as a drug, an appropriate transport vehicle has to be developed, in order to optimize its release in the human tissues. As a possible drug-delivery system, β-cyclodextrin (βCD) represents a promising scaffold which can encapsulate the melatonin, releasing when needed. In this work, we present a computational study supported by experimental IR spectra on inclusion MT/βCD complexes. The aim is to provide a robust, accurate and, at the same time, low-cost methodology to investigate these inclusion complexes both with static and dynamic simulations, in order to study the main actors that drive the interactions of melatonin with β-cyclodextrin and, therefore, to understand its release mechanism
On the interactions of melatonin/β-cyclodextrin inclusion complex: A novel approach combining efficient semiempirical extended tight-binding (xtb) results with ab initio methods
Melatonin (MT) is a molecule of paramount importance in all living organisms, due to its presence in many biological activities, such as circadian (sleep–wake cycle) and seasonal rhythms (reproduction, fattening, molting, etc.). Unfortunately, it suffers from poor solubility and, to be used as a drug, an appropriate transport vehicle has to be developed, in order to optimize its release in the human tissues. As a possible drug-delivery system, β-cyclodextrin (βCD) represents a promising scaffold which can encapsulate the melatonin, releasing when needed. In this work, we present a computational study supported by experimental IR spectra on inclusion MT/βCD complexes. The aim is to provide a robust, accurate and, at the same time, low-cost methodology to investigate these inclusion complexes both with static and dynamic simulations, in order to study the main actors that drive the interactions of melatonin with β-cyclodextrin and, therefore, to understand its release mechanism
Neuroprotective role of phosphoserine in primary open-angle glaucoma patients
OBJECTIVE: To evaluate the neuroprotective role of phosphoserine (P-Ser) in primary open-angle glaucoma (POAG) patients and to compare its therapeutic effectiveness to placebo treatment. PATIENTS AND METHODS: Fifty-one patients (24 males and 27 females) between 35 and 61 years (average 46 years ± 3.8 SD) affected by POAG were enrolled in this study. Patients were divided in two groups: group A included 28 subjects that received an oral P-Ser treatment for 12 months; and group B included 23 subjects that received an oral placebo treatment for 12 months. Complete ophthalmological examination, standard automated perimetric examination, analysis of ON fibers via scanning laser polarimetry and glaucoma staging was performed in all patients at enrolment and 1, 3, 6, and 12 months after. Statistical analysis was performed using STATA 14.0 (Collage Station, TX, USA). RESULTS: Mean deviation (MD) and pattern standard deviation (PSD) analysis by means of 30-2 full threshold of the visual fields (VFs), retinal nerve fiber layer (RNFL) thickness by means of GDx, and IOP were considered to evaluate P-Ser therapy effectiveness in both groups. A statistically significant improvement (p<0.05) in VF, RNFL thickness and IOP compared to pre-treatment was found in patients in group A. CONCLUSIONS: Our study shows a significant improvement in several variables in patients with glaucoma treated with P-Ser compared to placebo and suggests a potential neuroprotective effect of P-Ser in treating glaucoma patients in association with the traditional hypotonic topical therapy
Accelerator and Reactor Neutrino Oscillation Experiments in a Simple Three-Generation Framework
We present a new approach to the analysis of neutrino oscillation
experiments, in the one mass-scale limit of the three-generation scheme. In
this framework we reanalyze and recombine the most constraining accelerator and
reactor data, in order to draw precise bounds in the new parameter space. We
consider our graphical representations as particularly suited to show the
interplay among the different oscillation channels. Within the same framework,
the discovery potential of future short and long baseline experiments is also
investigated, in the light of both the recent signal from the LSND experiment
and the atmospheric neutrino anomaly.Comment: uuencoded compressed tar file. Figures (13) available by ftp to
ftp://eku.sns.ias.edu/pub/lisi/ (192.16.204.30). Submitted to Physical Review
Fine structure splittings of excited P and D states in charmonium
It is shown that the fine structure splittings of the and
excited states in charmonium are as large as those of the state if the
same is used. The predicted mass
GeV appears to be 120 MeV lower that the center of gravity of the
multiplet and lies below the threshold. Our value of
is approximately 80 MeV lower than that from the paper by Godfrey and Isgur
while the differences in the other masses are \la 20 MeV. Relativistic
kinematics plays an important role in our analysis.Comment: 12 page
More Straightforward Extraction of the Fundamental Lepton Mixing Parameters from Long-Baseline Neutrino Oscillations
We point out the simple reversibility between the fundamental neutrino mixing
parameters in vacuum and their effective counterparts in matter. The former can
therefore be expressed in terms of the latter, allowing more straightforward
extraction of the genuine lepton mixing quantities from a variety of
long-baseline neutrino oscillation experiments. In addition to the
parametrization-independent results, we present the formulas based on the
standard parametrization of the lepton flavor mixing matrix and give a typical
numerical illustration.Comment: RevTex 10 pages. Minor changes. Phys. Rev. D in printin
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