4,142 research outputs found
New interactions: past and future experiments
In this talk I will review the present status and future perspectives of some
popular extensions of the conventional three-neutrino oscillation scenario,
from a purely phenomenological point of view. For concreteness I will focus
only on three specific scenarios: non-standard neutrino interactions with
matters, models with extra sterile neutrinos, and neutrino decay and
decoherence.Comment: LaTeX file using jpconf class, 8 pages, 2 tables. Proceedings of the
"XXIII International Conference on Neutrino Physics and Astrophysics"
(Neutrino 08), Christchurch, New Zealand, May 25-31, 200
Performance study update of observations in divergent mode for the Cherenkov Telescope Array
Due to the limited field of view (FoV) of Cherenkov telescopes, the time
needed to achieve target sensitivity for surveys of the extragalactic and
Galactic sky is large. To optimize the time spent to perform such surveys, a
so-called "divergent mode" of the Cherenkov Telescope Array Observatory (CTAO)
was proposed as an alternative observation strategy to the traditional parallel
pointing. In the divergent mode, each telescope points to a position in the sky
that is slightly offset, in the outward direction, from the original center of
the field of view. This bring the advantage of increasing the total
instantaneous arrays' FoV. From an enlarged field of view also benefits the
search for very-high-energy transient sources, making it possible to cover
large sky regions in follow-up observations, or to quickly cover the
probability sky map in case of Gamma Ray Bursts (GRB), Gravitational Waves
(GW), and other transient events. In this contribution, we present the proposed
implementation of the divergent pointing mode and its first preliminary
performance estimation for the southern CTAO array
Performance study update of observations in divergent mode for the Cherenkov Telescope Array
Due to the limited field of view (FoV) of Cherenkov telescopes, the time
needed to achieve target sensitivity for surveys of the extragalactic and
Galactic sky is large. To optimize the time spent to perform such surveys, a
so-called "divergent mode" of the Cherenkov Telescope Array Observatory (CTAO)
was proposed as an alternative observation strategy to the traditional parallel
pointing. In the divergent mode, each telescope points to a position in the sky
that is slightly offset, in the outward direction, from the original center of
the field of view. This bring the advantage of increasing the total
instantaneous arrays' FoV. From an enlarged field of view also benefits the
search for very-high-energy transient sources, making it possible to cover
large sky regions in follow-up observations, or to quickly cover the
probability sky map in case of Gamma Ray Bursts (GRB), Gravitational Waves
(GW), and other transient events. In this contribution, we present the proposed
implementation of the divergent pointing mode and its first preliminary
performance estimation for the southern CTAO array.Comment: Presented at the 38th International Cosmic Ray Conference (ICRC
2023), 2023 (arXiv:2309.08219
Precision on leptonic mixing parameters at future neutrino oscillation experiments
We perform a comparison of the different future neutrino oscillation
experiments based on the achievable precision in the determination of the
fundamental parameters theta_{13} and the CP phase, delta, assuming that
theta_{13} is in the range indicated by the recent Daya Bay measurement. We
study the non-trivial dependence of the error on delta on its true value. When
matter effects are small, the largest error is found at the points where CP
violation is maximal, and the smallest at the CP conserving points. The
situation is different when matter effects are sizable. As a result of this
effect, the comparison of the physics reach of different experiments on the
basis of the CP discovery potential, as usually done, can be misleading. We
have compared various proposed super-beam, beta-beam and neutrino factory
setups on the basis of the relative precision of theta_{13} and the error on
delta. Neutrino factories, both high-energy or low-energy, outperform
alternative beam technologies. An ultimate precision on theta_{13} below 3% and
an error on delta of < 7^{\circ} at 1 sigma (1 d.o.f.) can be obtained at a
neutrino factory.Comment: Minor changes, matches version accepted in JHEP. 30 pages, 9 figure
Exact and Approximate Formulas for Neutrino Mixing and Oscillations with Non-Standard Interactions
We present, both exactly and approximately, a complete set of mappings
between the vacuum (or fundamental) leptonic mixing parameters and the
effective ones in matter with non-standard neutrino interaction (NSI) effects
included. Within the three-flavor neutrino framework and a constant matter
density profile, a full set of sum rules is established, which enables us to
reconstruct the moduli of the effective leptonic mixing matrix elements, in
terms of the vacuum mixing parameters in order to reproduce the neutrino
oscillation probabilities for future long-baseline experiments. Very compact,
but quite accurate, approximate mappings are obtained based on series
expansions in the neutrino mass hierarchy parameter \eta \equiv \Delta
m^2_{21}/\Delta m^2_{31}, the vacuum leptonic mixing parameter s_{13} \equiv
\sin\theta_{13}, and the NSI parameters \epsilon_{\alpha\beta}. A detailed
numerical analysis about how the NSIs affect the smallest leptonic mixing angle
\theta_{13}, the deviation of the leptonic mixing angle \theta_{23} from its
maximal mixing value, and the transition probabilities useful for future
experiments are performed using our analytical results.Comment: 29 pages, 8 figures, final version published in J. High Energy Phy
An Instanton Picture O.P.E. <A^2> Condensate?
Gluon two- and three-point Green Functions computed in Landau gauge from the
lattice show the existence of power corrections to the purely perturbative
expressions, that can be explained through an Operator Product Expansion as the
influence of a non gauge invariant mass dimension two condensate. The
relationship of this condensate with topological properties of QCD, namely
instantons, will be studied, giving a first estimate of the contribution of
instantons to this condensate based in the direct lattice measure, after a
cooling process, of the instanton liquid properties.Comment: Lattice2002(topology) contribution, 3 pages, 2 figure
, and the neutrino mass hierarchy at a double baseline Li/B -Beam
We consider a -Beam facility where Li and B ions are
accelerated at , accumulated in a 10 Km storage ring and let
decay, so as to produce intense and beams. These beams
illuminate two iron detectors located at Km and
Km, respectively. The physics potential of this setup is analysed in full
detail as a function of the flux. We find that, for the highest flux ( ion decays per year per baseline), the sensitivity to
reaches ; the sign of
the atmospheric mass difference can be identified, regardless of the true
hierarchy, for ; and, CP-violation
can be discovered in 70% of the -parameter space for , having some sensitivity to CP-violation down to
for .Comment: 35 pages, 20 figures. Minor changes, matches the published versio
EUROnu-WP6 2010 Report
This is a summary of the work done by the Working Package 6 (Physics) of the
EU project "EUROnu" during the second year of activity of the project.Comment: 82 pages, 51 eps figure
Instantons and Condensate
We argue that the is similar to .Comment: 6 pages, 1 fig., 1 tab., RevTeX to be use
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