217 research outputs found
Resolving the Mass Hierarchy with Atmospheric Neutrinos using a Liquid Argon Detector
We explore the potential offered by large-mass Liquid Argon detectors for
determination of the sign of Delta m_{31}^2, or the neutrino mass hierarchy,
through interactions of atmospheric neutrinos. We give results for a 100 kT
sized magnetized detector which provides separate sensitivity to \nu_\mu,
\bar{\nu}_\mu and, over a limited energy range, to \nu_e, \bar{\nu}_e.We also
discuss the sensitivity for the unmagnetized version of such a detector. After
including the effect of smearing in neutrino energy and direction and
incorporating the relevant statistical,theoretical and systematic errors, we
perform a binned \chi^2 analysis of simulated data. The \chi^2 is marginalized
over the presently allowed ranges of neutrino parameters and determined as a
function of \theta_{13}. We find that such a detector offers superior
capabilities for hierarchy resolution, allowing a > 4\sigma determination for a
100 kT detector over a 10 year running period for values of \sin^2 2\theta_{13}
\ge 0.05. For an unmagnetized detector, a 2.5\sigma hierarchy sensitivity is
possible for \sin^2 2\theta_{13} = 0.04.Comment: 13 pages, 3 figures, typing error in the abstract corrected, no other
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Large Matter Effects in Oscillations
We show that matter effects change the
oscillation probability by as much as 70% for certain ranges of energies and
pathlengths. Consequently, the survival
probability also undergoes large changes. A proper understanding of
survival rates must consider matter effects in as well as
. We comment on a) how these matter effects may be observed and the
sign of determined in atmospheric neutrino measurements and at
neutrino factories and b) how they lead to heightened sensitivity for small
.Comment: Version to appear in Phys. Rev. Let
A Study on the Relationship between Siltation and Flow Parameter of a Typical Alluvial River - Studied Open Channel Flow Bhogdoi River
The tendency of a river to change its course is the common feature of a river. This causes various problem to agricultural land, habitation, hydraulic structure etc located on the river banks. Soil erosion is one of the major threats to the society and it affects the economy of the state. It occurs when grains or assembly of grains are removed from the bank face by the flow. Due to strong forces of lift and drag exerted on the bank by flow, it detaches and removes soil from the intact soil. In our state as the mighty Brahmaputra river passes through the heart of Assam, therefore the affect of soil erosion is very horrible. From the earlier time various method are taken to eliminate soil erosion. The aim of this project is to record periodical observation of a tributary flowing into the river Brahmaputra to check its different properties i.e. the amount of silt carried, velocity during the period, discharge of the section, cross sectional properties and to study its various aspects to enhance some solution
Mass Hierarchy Determination via future Atmospheric Neutrino Detectors
We study the problem of determination of the sign of Delta m^2_{31}, or the
neutrino mass hierarchy, through observations of atmospheric neutrinos in
future detectors. We consider two proposed detector types :
(a) Megaton sized water Cerenkov detectors, which can measure the survival
rates of nu_\mu + \bar{\nu}_\mu and nu_e + \bar{\nu}_e and (b) 100 kton sized
magnetized iron detectors, which can measure the survival rates of \nu_\mu and
\bar{\nu}_\mu. For energies and path-lengths relevant to atmospheric neutrinos,
these rates obtain significant matter contributions from P_{\mu e}, P_{\mu \mu}
and P_{ee}, leading to an appreciable sensitivity to the hierarchy. We do a
binned \chi^2 analysis of simulated data in these two types of detectors which
includes the effect of smearing in neutrino energy and direction and
incorporates detector efficiencies and relevant statistical, theoretical and
systematic errors. We also marginalize the \chi^2 over the allowed ranges of
neutrino parameters in order to accurately account for their uncertainties.
Finally, we compare the performance of both types of detectors vis a vis the
hierarchy determination.Comment: 36 pages, 13 figures, revised version accepted in Physical Review
Neutrino mass hierarchy determination via atmospheric neutrinos with future detectors
The issue of determining the neutrino mass hierarchy is one of the outstanding questions in neutrino physics. We consider the potential of hierarchy determination using atmospheric neutrinos as the source in three different proposed future detectors: A large Iron Calorimeter detector, a megaton Water Cerenkov detector and a large-mass Liquid Argon detector. If the mixing angle θ13 is about 10° (close to CHOOZ upper bound), the hierarchy sensitivity is essentially determined by resonant matter effects. To maximize the potential of these effects in atmospheric neutrinos, charge discrimination capability in the detector is desirable. Hence, detectors with this capability have an advantage in hierarchy determination. We compare and contrast the performance of the above three detectors in this respect. We perform a realistic analysis of the above future detectors for atmospheric neutrinos and show that it is possible to achieve a significant hierarchy sensitivity if the detector characteristics are favourable
Neutrino mass hierarchy and octant determination with atmospheric neutrinos
The recent discovery by the Daya-Bay and RENO experiments, that \theta_{13}
is nonzero and relatively large, significantly impacts existing experiments and
the planning of future facilities. In many scenarios, the nonzero value of
\theta_{13} implies that \theta_{23} is likely to be different from \pi/4.
Additionally, large detectors will be sensitive to matter effects on the
oscillations of atmospheric neutrinos, making it possible to determine the
neutrino mass hierarchy and the octant of \theta_{23}. We show that a 50 kT
magnetized liquid argon neutrino detector can ascertain the mass hierarchy with
a significance larger than 4 sigma with moderate exposure times, and the octant
at the level of 2-3 sigma with greater exposure.Comment: 4 pages, 4 figures. Version published in Phys. Rev. Let
Bis(2,6-diaminopyridinium)–adipate–adipic acid–water (2/1/1/2)
The crystal structure of the title compound, 2C5H8N3
+·C6H8O4
2−·C6H10O4·2H2O, consists of aminopyridinium cations, adipate dianions, adipic acid molecules and disordered solvent water molecules [occupancies 0.50 (4) and 0.50 (4)]. Both the adipate and adipic acid are located across inversion centres. Eight-membered hydrogen-bonded rings exist involving aminopyridinium and adipate ions. Adipic acid molecules and adipate anions are linked into zigzag supramolecular chains by O—H⋯O hydrogen bonds
Molecular cloning of HSP17 gene (sHSP) and their differential expression under exogenous putrescine and heat shock in wheat (Triticum aestivum)
Polyamines (PAs) are low molecular weight ubiquitous nitrogenous compounds found in all the living organisms, which have been implicated in the expression of various stress-proteins against the abiotic stresses. Small heat shock proteins (sHSPs) are of particular importance in the thermotolerance and have been reported to act as molecular chaperones preventing denaturation or aggregation of the target proteins. Here, we report cloning of a small HSP of ~573 bp from C-306 cultivar of wheat (Triticum aestivum L), having open reading frame of 162 amino acids. In silico analysis showed the presence of an alpha crystalline domain (ACD), the signature domain for small HSPs. Consensus localization prediction (ConLoc) provides 98% consensus prediction of HSP17 in the nucleus. Quantitative real time polymerase chain reaction (qRT-PCR) analysis of HSP17 gene showed maximum (34 fold) transcript in C-306 and minimum (1.5 fold) in HD2329 cultivars of wheat in response to differential treatment of putrescine (1.5 to 2.5 mM + heat shock of 42°C for 2 h). Putrescine seems to enhance the transcript levels against the heat shock much more pronounced in thermotolerant than in the susceptible cultivars.Key words: Triticum aestivum, heat stress, small heat shock protein, putrescine, HSP17, polyamine, domain, cloning
Earth Matter Effects at Very Long Baselines and the Neutrino Mass Hierarchy
We study matter effects which arise in the muon neutrino oscillation and
survival probabilities relevant to atmospheric neutrino and very long baseline
beam experiments. The inter-relations between the three probabilities P_{\mu
e}, P_{\mu \tau} and P_{\mu \mu} are examined. It is shown that large and
observable sensitivity to the neutrino mass hierarchy can be present in P_{\mu
\mu} and P_{\mu \tau}. We emphasize that at baselines of > 7000 Km, matter
effects in P_{\mu \tau} can be large under certain conditions. The muon
survival rates in experiments with very long baselines thus depend on matter
effects in both P_{\mu \tau} and P_{\mu e}. We indicate where these effects are
sensitive to \theta_{13}, and identify ranges of E and L where the event rates
increase with decreasing \theta_{13}, providing a handle to probe small
\theta_{13}. The effect of parameter degeneracies in the three probabilities at
these baselines and energies is studied in detail. Realistic event rate
calculations are performed for a charge discriminating 100 kT iron calorimeter
which demonstrate the possibility of realising the goal of determining the
neutrino mass hierarchy using atmospheric neutrinos. It is shown that a careful
selection of energy and baseline ranges is necessary in order to obtain a
statistically significant signal, and that the effects are largest in bins
where matter effects in both P_{\mu e} and P_{\mu \tau} combine constructively.
Under these conditions, upto a 4\sigma signal for matter effects is possible
(for \Delta_{31}>0) within a timescale appreciably shorter than the one
anticipated for neutrino factories.Comment: 40 pages, 27 figures, version to match the published versio
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