231 research outputs found
Minimal Neutrino Beta Beam for Large theta_13
We discuss the minimum requirements for a neutrino beta beam if theta_13 is
discovered by an upcoming reactor experiment, such as Double Chooz or Daya Bay.
We require that both neutrino mass hierarchy and leptonic CP violation can be
measured to competitive precisions with a single-baseline experiment in the
entire remaining theta_13 range. We find that for very high isotope production
rates, such as they might be possible using a production ring, a (B,Li) beta
beam with a gamma as low as 60 could already be sufficient to perform all of
these measurements. If only the often used nominal source luminosities can be
achieved, for example, a (Ne,He) beta beam from Fermilab to a possibly existing
water Cherenkov detector at Homestake with gamma \sim 190-350 (depending on the
Double Chooz best-fit) could outperform practically any other beam technology
including wide-band beam and neutrino factory.Comment: 11 pages, 2 figures, 1 tabl
Neutrino Mixings and Leptonic CP Violation from CKM Matrix and Majorana Phases
The high scale mixing unification hypothesis recently proposed by three of us
(R. N. M., M. K. P. and G. R.) states that if at the seesaw scale, the quark
and lepton mixing matrices are equal then for quasi-degenerate neutrinos,
radiative corrections can lead to large solar and atmospheric mixings and small
reactor angle at the weak scale in agreement with data. Evidence for
quasi-degenerate neutrinos could, within this framework, be interpreted as a
sign of quark-lepton unification at high scale. In the current work, we extend
this model to show that the hypothesis works quite successfully in the presence
of CP violating phases (which were set to zero in the first paper). In the case
where the PMNS matrix is identical to the CKM matrix at the seesaw scale, with
a Dirac phase but no Majorana phase, the low energy Dirac phase is predicted to
be () and leptonic CP-violation parameter and . If on the other hand, the
PMNS matrix is assumed to also have Majorana phases initially, the resulting
theory damps radiative magnification phenomenon for a large range of parameters
but nevertheless has enough parameter space to give the two necessary large
neutrino mixing angles. In this case, one has and as large as which are accessible to long
baseline neutrino oscillation experiments.Comment: 15 pages and 10 figures, typo correcte
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
Probing the Neutrino Mass Hierarchy with Super-Kamiokande
We show that for recently discovered large values of theta(13), a superbeam
with an average neutrino energy of ~ 5 GeV, such as those being proposed at
CERN, if pointing to Super-Kamiokande (L = 8770 km), could reveal the neutrino
mass hierarchy at 5 sigma in less than two years irrespective of the true
hierarchy and CP phase. The measurement relies on the near resonant matter
effect in the numu to nue oscillation channel, and can be done counting the
total number of appearance events with just a neutrino beam.Comment: 16 pages, 7 pdf figures, 2 tables. Format changed and text extended.
Four new pdf figures added. Dependency of the result on 1-3 mixing angle
discussed. Conclusions unchanged. Accepted in JHE
Information Content of Implicit Spot Prices Embedded in Single Stock Future Prices: Evidence from Indian Market
This study examines the information content of pricing error, measured by the difference between the implied price computed using the cost of carry model and the spot price of Single Stock Futures (SSFs), traded on National Stock Exchange (NSE), India. The returns of portfolios, based on ranking of such pricing errors, are investigated. The consistency of results is verified by controlling for established risk factors, that is, market, size, value and momentum premium, and idiosyncratic factors such as firm’s liquidity and size. Our study reveals that the pricing error is a priced risk factor that contains incremental information about stock returns of day t, and not beyond. We conclude that implied spot prices from stock futures market are useful for traders to profit in the spot market
Potential of optimized NOvA for large theta(13) & combined performance with a LArTPC & T2K
NOvA experiment has reoptimized its event selection criteria in light of the
recently measured moderately large value of theta(13). We study the improvement
in the sensitivity to the neutrino mass hierarchy and to leptonic CP violation
due to these new features. For favourable values of deltacp, NOvA sensitivity
to mass hierarchy and leptonic CP violation is increased by 20%. Addition of 5
years of neutrino data from T2K to NOvA more than doubles the range of deltacp
for which the leptonic CP violation can be discovered, compared to stand alone
NOvA. But for unfavourable values of deltacp, the combination of NOvA and T2K
are not enough to provide even a 90% C.L. hint of hierarchy discovery.
Therefore, we further explore the improvement in the hierarchy and CP violation
sensitivities due to the addition of a 10 kt liquid argon detector placed close
to NOvA site. The capabilities of such a detector are equivalent to those of
NOvA in all respects. We find that combined data from 10 kt liquid argon
detector (3 years of nu + 3 years of nubar run), NOvA (6 years of nu + 6 years
of nubar run) and T2K (5 years of nu run) can give a close to 2 sigma hint of
hierarchy discovery for all values of deltacp. With this combined data, we can
achieve CP violation discovery at 95% C.L. for roughly 60% values of deltacp.Comment: 22 pages, 24 pdf figures, 5 tables. In the appendix, new results are
presented with conservative choices of central values of oscillation
parameters. New references are added. Accepted in JHE
MiniBooNE Oscillation Results 2011
The MiniBooNE neutrino oscillation search experiment at Fermilab has recently
updated results from a search for
oscillations, using a data sample corresponding to
protons on target in anti-neutrino mode. This high statistics result represent
an increase in statistics of 52% compared to result published in 2010. An
excess of 57.7 28.5 events is observed in the energy range 200 MeV 3000 MeV. The data favor LSND-like
oscillations over a background only hypothesis at 91.1% confidence level in the
energy range 475 3000 MeV.Comment: 4 pages, 6 figures, talk given at NuFact 2011, XIIIth
InternationalWorkshop on Neutrino Factories, Super beams and Beta beams,
CERN/UNIGE, Geneva, Switzerland, August 1-6, 201
Phonon Hall effect in ionic crystals in the presence of static magnetic field
We study phonon Hall effect (PHE) for ionic crystals in the presence of
static magnetic field. Using Green-Kubo formula, we present an exact
calculation of thermal conductivity tensor by considering both positive and
negative frequency phonons. Numerical results are shown for some lattices such
as hexagonal lattices, triangular lattices, and square lattices. We find that
the PHE occurs on the nonmagnetic ionic crystal NaCl, although the magnitude is
very small which is due to the tiny charge-to-mass ratio of the ions. The
off-diagonal thermal conductivity is finite for nonzero magnetic field and
changes sign for high value of magnetic field at high temperature. We also
found that the off-diagonal thermal conductivity diverges as at low
temperature
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