161 research outputs found
Muonless Events in ICAL at INO
The primary physics signal events in the ICAL at INO are the
charged current (CC) interactions with a well defined muon track. Apart from
these events, ICAL can also detect other types of neutrino interactions, i.e.
the electron neutrino charged current interactions and the neutral current
events. It is possible to have a dataset containing mostly CC events,
by imposing appropriate selection cuts on the events. The CC and
the neutral current events form the background to these events. This study uses
the Monte Carlo generated neutrino events, to design the necessary selection
cuts to obtain a CC rich dataset. An optimized set of constraints are
developed which balance the need for improving the purity of the sample and
having a large enough event sample. Depending on the constraints used, one can
obtain a neutrino data sample, with the purity of events varying
between 55% to 70%.Comment: 21 pages, 6 figure
Testing LSND at long-baseline neutrino experiments
Recently it was suggested that two very different mass-squared differences
play a role in atmospheric neutrino oscillations. The larger of these also
accounts for the LSND result and the smaller of these also drives the solar
neutrino oscillations. We consider the predictions of this scheme for
long-baseline experiments. We find that high statistics experiments, such as
MINOS, can observe a clean signal for this scheme, which is clearly
distinguishable from the usual scheme of atmospheric neutrino oscillations
driven by a single mass-squared difference.Comment: 13 pages, 3 figure
Non-Zero and in a Neutrino Mass Model with Symmetry
In this paper, we consider a neutrino mass model based on symmetry. The
spontaneous symmetry breaking in this model is chosen to obtain tribimaximal
mixing in the neutrino sector. We introduce invariant
perturbations in this model which can give rise to acceptable values of
and . Perturbation in the charged lepton sector
alone can lead to viable values of , but cannot generate
. Perturbation in the neutrino sector alone can lead to acceptable
and maximal CP violation. By adjusting the magnitudes of
perturbations in both sectors, it is possible to obtain any value of
.Comment: 16 pages, 3 figure
The need for an early anti-neutrino run of NOvA
The moderately large value of \ty, measured recently by reactor
experiments, is very welcome news for the future neutrino experiments. In
particular, the \nova experiment, with 3 years each of and \anu runs,
will be able to determine the mass hierarchy if one of the following two
favourable combinations is true: normal hierarchy with -180^\circ \leq \dcp
\leq 0 or inverted hierarchy with 0\leq \dcp \leq 180^\circ. In this report,
we study the hierarchy reach of the first 3 years of \nova data. Since \sin^2
2 \tz is measured to be non-maximal, \tz can be either in the lower or
higher octant. Pure data is affected by \ty-hierarchy and
octant-hierarchy degeneracies, which limit the hierarchy sensitivity of such
data. A combination of and \anu data is not subject to these
degeneracies and hence has much better hierarchy discrimination capability. We
find that, with a 3 year run, hierarchy determination is possible for
only two of the four octant-hierarchy combinations. Equal 1.5 year runs in
and \anu modes give good hierarchy sensitivity for all the four
combinations
Re-examining sin(2beta) and Delta m(d) from evolution of B(d) mesons with decoherence
In the time evolution of neutral meson systems, a perfect quantum coherence
is usually assumed. The important quantities of the B(d) system, such as sin
(2beta) and Delta m(d), are determined under this assumption. However, the
meson system interacts with its environment. This interaction can lead to
decoherence in the mesons even before they decay. In our formalism this
decoherence is modelled by a single parameter lambda. It is desirable to
re-examine the procedures of determination of sin(2beta) and Delta m(d) in
meson systems with decoherence. We find that the present values of these two
quantities are modulated by lambda. Re-analysis of B(d) data from B-factories
and LHCb can lead to a clean determination of lambda, sin(2beta) and Delta
m(d).Comment: Version accepted for publication in Physics Letters
Getting the best out of T2K and NOvA
We explore the combined physics potential of T2K and NOvA in light of the
moderately large measured value of theta13. For sin^2 2*theta13 = 0.1, which is
close to the best fit value, a 90% C.L. evidence for the hierarchy can be
obtained only for the combinations (Normal hierarchy, -170 <= deltaCP <= 0) and
(Inverted hierarchy, 0 <= deltaCP <= 170), with the currently planned runs of
NOvA and T2K. However, the hierarchy can essentially be determined for any
value of deltaCP, if the statistics of NOvA are increased by 50% and those of
T2K are doubled. Such an increase will also give an allowed region of deltaCP
around its true value, except for the CP conserving cases deltaCP = 0 or 180.
We demonstrate that any measurement of deltaCP is not possible without first
determining hierarchy. We find that comparable data from a shorter baseline (L
~ 130 km) experiment will not lead to any significant improvement.Comment: Version published in Phys. Rev.
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