79 research outputs found
Octant Degeneracy, Quadrant of leptonic CPV phase at Long Baseline Neutrino Experiments and Baryogenesis
In a recent work by us, we have studied, how CP violation discovery potential
can be improved at long baseline neutrino experiments (LBNE/DUNE), by combining
with its ND (near detector) and reactor experiments. In this work, we discuss
how this study can be further analysed to resolve entanglement of the quadrant
of leptonic CPV phase and Octant of atmospheric mixing angle ,
at LBNEs. The study is done for both NH (Normal hierarchy) and IH (Inverted
hierarchy), HO (Higher Octant) and LO (Lower Octant). We show how baryogenesis
can enhance the effect of resolving this entanglement, and how possible values
of the leptonic CP-violating phase can be predicted in this
context. With respect to the latest global fit data of neutrino mixing angles,
we predict the values of for different cases. In this context
we present favoured values of ( range at 2 ) constrained by the latest updated BAU range and also confront
our predictions of with an up-to-date global analysis of
neutrino oscillation data. We find that some region of the favoured parameter space lies within the best fit values around . A detailed analytic and numerical study of
baryogenesis through leptogenesis is performed in this framework in a model
independent way.Comment: 14 pages, 5 figures, 2 Tables, New Analysi
Measuring the Sterile Neutrino CP Phase at DUNE and T2HK
The CP phases associated with the sterile neutrino cannot be measured in the
dedicated short-baseline experiments being built to test the sterile neutrino
hypothesis. On the other hand, these phases can be measured in long-baseline
experiments, even though the main goal of these experiments is not to test or
measure sterile neutrino parameters. In particular, the sterile neutrino phase
affects the charged-current electron appearance data in
long-baseline experiment. In this paper we show for the first time how well the
sterile neutrino phase can be measured by the next-generation
long-baseline experiments DUNE, T2HK (and T2HKK). We also show the expected
precision with which this sterile phase can be measured by combining the DUNE
data with data from T2HK or T2HKK. We also present the sensitivity of these
experiments to the sterile mixing angles, both by themselves, as well as when
DUNE is combined with T2HK or T2HKK.Comment: Published in EPJ C with minor correction
Exploring fake solutions in the sterile neutrino sector at long-baseline experiments
Active-sterile neutrino mixing is known to affect the neutrino oscillation
probabilities at both short as well as long-baselines. In particular,
constraints on active-sterile neutrino oscillation parameters can be obtained
from long-baseline experiments such as T2HK and DUNE. We present here existence
of fake solution in the appearance channel for the 3+1 scenario at
long-baseline experiments. We show that the appearance probability is same for
values of for which the fast oscillations are averaged out
and for . The fake solution does not
appear for the disappearance channel.Comment: 17 pages, 6 figures, accepted with some modification
Effect of Non Unitarity on Neutrino Mass Hierarchy determination at DUNE, NOA and T2K
The neutrino mass ordering is one of the principal unknowns in the neutrino
sector. Long baseline neutrino experiments have the potential of resolving this
issue as they are sensitive to large matter effects. The superbeam experiment
DUNE is one of the most promising candidates to study the neutrino mass
hierarchy, along with NOA and T2K. But in the presence of non unitarity of
the leptonic mixing matrix, the capability of such experiments to discriminate
between the two hierarchies gets suppressed. The mass hierarchy sensitivity of
DUNE decreases in the presence of new physics. In this paper we analyze the
origin and extent of this loss of sensitivity at the level of oscillation
probabilities, events, mass hierarchy sensitivity and the discovery reach of
DUNE, NOA and T2K.Comment: 23 pages, 9 figures, modified version, new text and figure added,
accepted for publication in Nuclear Physics
Trilinear Neutral Gauge Boson Couplings
We study the CP even trilinear neutral gauge boson vertices at one-loop in
the context of the Standard Model and the Minimal Supersymmetric Standard
Model, assuming two of the vector bosons are on-shell. We also study the
changes in the form-factors when these two bosons are off-shell.Comment: 19 pages, latex, a detailed study of off-shell form-factors included.
To appear in International Journal of Modern Physics,
Capabilities of long-baseline experiments in the presence of a sterile neutrino
Assuming that there is a sterile neutrino, we ask what then is the ability of
long-baseline experiments to i) establish that neutrino oscillation violates
CP, ii) determine the three-neutrino mass ordering, and iii) determine which
CP-violating phase or phases are the cause of any CP violation that may be
observed. We find that the ability to establish CP violation and to determine
the mass ordering could be very substantial. However, the effects of the
sterile neutrino could be quite large, and it might prove very difficult to
determine which phase is responsible for an observed CP violation. We explain
why a sterile neutrino changes the long-baseline sensitivities to CP violation
and to the mass ordering in the ways that it does. We note that long-baseline
experiments can probe the presence of sterile neutrinos in a way that is
different from, and complementary to, the probes of short-baseline experiments.
We explore the question of how large sterile-active mixing angles need to be
before long-baseline experiments can detect their effects, or how small they
need to be before the interpretation of these experiments can safely disregard
the possible existence of sterile neutrinos.Comment: Published in JHEP, 24 pages, 12 figures, IH results adde
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