6,766 research outputs found
disappearance at the SPL, T2K-I and the Neutrino Factory
We study the disappearance channel at T2K-phase I and the SPL and
analyse the achievable reduction of present uncertainties in and
. We analyse the impact of discrete ambiguities in
sign() and sign(). We show how the
disappearance channel at the Neutrino Factory is complementary to the
``golden'' and ``silver'' appearance channels and can be used to reduce the
eightfold-ambiguity problem in ().Comment: 2 pages, 3 epsfig; NUFACT'05, 21-26 June 2005, Frascat
Micro-orbits in a many-branes model and deviations from Newton's law
We consider a 5-dimensional model with geometry , with compactification radius . The Standard Model particles are
localized onto a brane located at y=0, with identical branes localized at
different points in the extra dimension. Objects located on our brane can orbit
around objects located on a brane at a distance , with an orbit and a
period significantly different from the standard Newtonian ones. We study the
kinematical properties of the orbits, finding that it is possible to
distinguish one motion from the other in a large region of the initial
conditions parameter space. This is a warm-up to study if a SM-like mass
distribution on one (or more) distant brane(s) may represent a possible dark
matter candidate. After using the same technique to the study of orbits of
objects lying on the same brane (), we apply this method to detect generic
deviations from the inverse-square Newton's law. We propose a possible
experimental setup to look for departures from Newtonian motion in the
micro-world, finding that an order of magnitude improvement on present bounds
can be attained at the 95% CL under reasonable assumptions.Comment: Two-column format (20 pages), 10 figures; minor corrections and some
added reference
Full QCD on APE100 Machines
We present the first tests and results from a study of QCD with two flavours
of dynamical Wilson fermions using the Hybrid Monte Carlo Algorithm (HMCA) on
APE100 machines.Comment: 23 pages, LaTeX, 13 PS figures not include
Physics reach of -beams and -factories: the problem of degeneracies
We discuss the physics reach of -Beams and -Factories from a
theoretical perspective, having as a guideline the problem of degeneracies. The
presence of degenerate solutions in the measure of the neutrino oscillation
parameters and is, in fact, the main problem that have
to be addressed in planning future neutrino oscillation experiments. If
degeneracies are not (at least partially) solved, it will be almost impossible
to perform, at any future facility, precise measurements of
and/or . After a pedagogical introduction on why degenerate solutions
arise and how we can get rid of them, we analyze the physics reach of current
-beam and -factory configurations. The physics reach of the
"standard" \BB is severely affected by degeneracies while a better result can
be obtained by higher- setups. At the \NF the combination of Golden and
Silver channels can solve the eightfold degeneracy down to Comment: 5 pages, 6 epsfig; NUFACT'05, 21-26 June 2005, Frascat
Invisible Z decay width bounds on active-sterile neutrino mixing in the (3+1) and (3+2) models
In this work we consider the standard model extended with singlet sterile
neutrinos with mass in the eV range and mixed with the active neutrinos. The
active-sterile neutrino mixing renders new contributions to the invisible Z
decay width which, in the case of light sterile neutrinos, depends on the
active-sterile mixing matrix elements only. We then use the current
experimental value of the invisible Z decay width to obtain bounds on these
mixing matrix elements for both (3+1) and (3+2) models.Comment: 10 pages, 5 figure
disappearance at the SPL, T2K-I, NOA and the Neutrino Factory
We study the measurement of the atmospheric neutrino oscillation parameters,
and , at the disappearance channel at
three conventional beam facilities, the SPL, T2K-phase I and NOA. These
two parameters have been shown to be of crucial importance in the measurement
of two of the unknowns of the PMNS mixing matrix, and the
leptonic CP-violating phase . In our analyis, the effect of the two
discrete ambiguities, and , is explicitly taken into account. We analyse also the
disappearance channel at the Neutrino Factory, and combine it with the
``golden'' and ``silver'' appearance
channels to study its impact on the measurement of and .
Eventually, we present the sensitivity of the four facilities to different
observables: , , maximal , the sign of the
atmospheric mass difference, , and the -octant,
.Comment: 40 pages using epsfig; bibliography modifie
Degeneracies at a beta-Beam and a Super-Beam Facility
The presence of degeneracies can considerably worsen the measure of the
neutrino oscillation parameters and . We study the
physics reach of a specific ``CERN'' setup, using a standard -Beam and
Super-Beam facility. These facilities have a similar sensitivity in both
parameters. Their combination does not provide any dramatic improvement as
expected due to their almost identical L/E ratio. We analyse if adding the
correspondent disappearance channels can help in reducing the effect of
degeneracies in the measure.Comment: 5 pages, 7 eps figure
Clone flow analysis for a theory inspired Neutrino Experiment planning
The presence of several clone solutions in the simultaneous measurement of
() has been widely discussed in literature. In this letter
we write the analytical formulae of the clones location in the
() plane as a function of the physical input pair
(). We show how the clones move with changing
. The "clone flow" can be significantly different if computed
(naively) from the oscillation probabilities or (exactly) from the
probabilities integrated over the neutrino flux and cross-section.
Using our complete computation we compare the clone flow of a set of possible
future neutrino experiments: the CERN SuperBeam, BetaBeam and Neutrino Factory
proposals. We show that the combination of these specific BetaBeam and
SuperBeam does not help in solving the degeneracies. On the contrary, the
combination of one of them with the Neutrino Factory Golden and Silver channel
can be used, from a theoretical point of view, to solve completely the
eightfold degeneracy.Comment: 23 pages, using epsfi
Circulating SIRT1 inversely correlates with epicardial fat thickness in patients with obesity
Background and aim: Obesity is increasing worldwide and is related to undesirable cardiovascular outcomes. Epicardial fat (EF), the heart visceral fat depot, increases with obesity and correlates with cardiovascular risk. SIRT1, an enzyme regulating metabolic circuits linked with obesity, has a cardioprotective effect and is a predictor of cardiovascular events. We aimed to assess the relationship of EF thickness (EFT) with circulating SIRT1 in patients with obesity.
Methods and results: Sixty-two patients affected by obesity and 23 lean controls were studied. Plasma SIRT1 concentration was determined by enzyme-linked immunosorbent assay (ELISA). EFT was measured by echocardiography. Body mass index (BMI), waist circumference, heart rate (HR), blood pressure, and laboratory findings (fasting glucose, insulin, HbA1c, cholesterol, and triglycerides) were assessed. SIRT1 was significantly lower (P = 0.002) and EFT was higher (P < 0.0001) in patients with obesity compared with lean controls. SIRT1 showed a negative correlation with EFT and HR in the obesity group (rho = -0.350, P = 0.005; rho = -0.303, P = 0.008, respectively). After adjustment for obesity-correlated variables, multiple linear regression analysis showed that EFT remained the best correlate of SIRT1 (beta = -0.352, P = 0.016).
Conclusions: Circulating SIRT1 correlates with the visceral fat content of the heart. Serum SIRT1 levels might provide additional information for risk assessment of coronary artery disease in patients with obesity. (C) 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved
Sterile neutrinos in neutrinoless double beta decay
We study possible contribution of the Majorana neutrino mass eigenstate
dominated by a sterile neutrino component to neutrinoless double beta
() decay. From the current experimental lower bound on the
-decay half-life of Ge we derive stringent constraints
on the mixing in a wide region of the values of mass. We
discuss cosmological and astrophysical status of in this mass region.Comment: 6 pages, 1 figure; v2 added comments and reference
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