481 research outputs found
Determination of the neutrino mass hierarchy in the regime of small matter effect
We point out a synergy between T-conjugated oscillation channels in the
determination of the neutrino mass hierarchy with oscillation experiments with
relatively short baselines (L < 700 km), where the matter effect is small. If
information from all four oscillation channels ,
, and is
available, a matter effect of few percent suffices to break the sign-degeneracy
and allows to determine the neutrino mass hierarchy. The effect is discussed by
analytical considerations of the relevant oscillation probabilities, and
illustrated with numerical simulations of realistic experimental setups.
Possible configurations where this method could be applied are the combination
of a super beam experiment with a beta beam or a neutrino factory, or a (low
energy) neutrino factory using a detector with muon and electron charge
identification.Comment: 13 pages, 3 figure
LHC phenomenology of supersymmetric models beyond the MSSM
We discuss various phenomenological aspects of supersymmetric models beyond
the MSSM. A particular focus is on models which can correctly explain neutrino
data and the possiblities of LHC to identify the underlying scenario.Comment: Contribution to the 16th International Symposium on Particles,
Strings and Cosmology (PASCOS 2010), Valencia (Spain), July 19-23, 201
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
Theta-13 as a Probe of Mu-Tau symmetry for Leptons
Many experiments are being planned to measure the neutrino mixing parameter
using reactor as well as accelerator neutrino beams. In this
note, the theoretical significance of a high precision measurement of this
parameter is discussed. It is emphasized that it will provide crucial
information about different ways to understand the origin of large atmospheric
neutrino mixing and move us closer towards determining the neutrino mass
matrix. For instance if exact symmetry in the
neutrino mass matrix is assumed to be the reason for maximal
mixing, one gets . Whether or can provide information about the way the
symmetry breaking manifests in the case of normal hierarchy. We also discuss
the same question for inverted hierarchy as well as possible gauge theories
with this symmetry.Comment: 12 pages; no figures; latex; more exact expressions given for some
parameters and minor typos corrected; paper accepted for publication in JHE
On the Evolution of the Neutrino State inside the Sun
We reexamine the conventional physical description of the neutrino evolution
inside the Sun. We point out that the traditional resonance condition has
physical meaning only in the limit of small values of the neutrino mixing
angle, theta<<1. For large values of theta, the resonance condition specifies
neither the point of the maximal violation of adiabaticity in the nonadiabatic
case, nor the point where the flavor conversion occurs at the maximal rate in
the adiabatic case. The corresponding correct conditions, valid for all values
of theta including theta>pi/4, are presented. An adiabaticity condition valid
for all values of theta is also described. The results of accurate numerical
computations of the level jumping probability in the Sun are presented. These
calculations cover a wide range of Delta m^2, from the vacuum oscillation
region to the region where the standard exponential approximation is good. A
convenient empirical parametrization of these results in terms of elementary
functions is given. The matter effects in the so-called "quasi-vacuum
oscillation regime" are discussed. Finally, it is shown how the known
analytical results for the exponential, 1/x, and linear matter distributions
can be simply obtained from the formula for the hyperbolic tangent profile. An
explicit formula for the jumping probability for the distribution N_e ~
(coth(x/l) +- 1) is obtained.Comment: 34 pages, 8 figure
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