7,907 research outputs found

    Radiative magnification of neutrino mixings and a natural explanation of the neutrino anomalies

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    We show that the neutrino mixing pattern with the large mixing required for the atmospheric neutrino problem and the small mixing angle MSW solution for the solar neutrino problem can be naturally generated through radiative magnification, even though all the mixing angles at the seesaw scale may be small. This can account for the neutrino anomalies as well as the CHOOZ constraints in the context of quark-lepton unified theories, where the quark and lepton mixing angles are expected to be similar in magnitude at the high scale. We also indicate the 4ν\nu mixing scenarios for which this mechanism of radiative magnification can provide a natural explanation.Comment: 14 pages RevTex, 2 eps figure

    Neutron matter - Quark matter phase transition and Quark star

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    We consider the neutron matter quark matter phase transition along with possible existence of hybrid quark stars. The equation of state for neutron matter is obtained using a nonperturbative method with pion dressing of the neutron matter and an analysis similar to that of symmetric nuclear matter. The quark matter sector is treated perturbatively in the small distance domain. For bag constant B1/4B^{1/4}=148 MeV, a first order phase transition is seen. In the context of neutron quark hybrid stars, Tolman-Oppenheimer-Volkoff equations are solved using the equations of state for quark matter and for neutron matter with a phase transition as noted earlier. Stable solutions for such stars are obtained with the Chandrasekhar limit as 1.58 MM_\odot and radius around 10 km. The bulk of the star is quark matter with a thin crust of neutron matter of less than a kilometer.Comment: 28 pages including 9 figures, Revtex, IP/BBSR/92-8

    Vanishing corrections on the intermediate scale and implications for unification of forces

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    In two-step breaking of a class of grand unified theories including SO(10),we prove a theorem showing that the scale MIM_I where the Pati-Salam gauge symmetry with parity breaks down to the standard gauge group,has vanishing corrections due to all sources emerging from higher scales μ>MI \mu >M_I such as the one-loop and all higher loop effects,the GUT-threshold,gravitational smearing,and string threshold effects. Implications of such a scale for the unification of gauge couplings with small Majorana neutrino masses are discussed.In string inspired SO(10) we show that MI5×1012M_I \simeq 5\times 10^{12},needed for neutrino masses,with the GUT scale MUMstrM_U \simeq M_{str} can be realized provided certain particle states in the predicted spectum are light.Comment: 21 pages, Late

    Negative differential resistance in nanoscale transport in the Coulomb blockade

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    Motivated by recent experiments, we have studied transport behavior of coupled quantum dot systems in the Coulomb blockade regime using the master (rate) equation approach. We explore how electron-electron interactions in a donor-acceptor system, resembling weakly coupled quantum dots with varying charging energy, can modify the systems response to an external bias, taking it from normal Coulomb blockade behavior to negative differential resistance (NDR) in the curent-voltage characteristics

    New Uncertainties in QCD-QED Rescaling Factors using Quadrature Method

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    In this paper we briefly outline the quadrature method for estimating uncertainties in a function of several variables and apply it to estimate the numerical uncertainties in QCD-QED rescaling factors. We employ here the one-loop order in QED and three-loop order in QCD evolution equations of fermion mass renormalization. Our present calculations are found to be new and also reliable compared to the earlier values employed by various authors.Comment: 14 page

    Radiative stability of neutrino-mass textures

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    Neutrino-mass textures proposed at high-scales are known to be unstable against radiative corrections especially for nearly degenerate eigen values. Within the renormalization group constraints we find a mechanism in a class of gauge theories which guarantees reproduction of any high-scale texture at low energies with radiative stability. We also show how the mechanism explains solar and atmospheric neutrino anomalies through the bimaximal texture at high scale.Comment: 4 pages REVTEX, 1 Postscript fi

    Running Neutrino Masses, Leptonic Mixing Angles and CP-Violating Phases: From MZM_{\rm Z} to ΛGUT\Lambda_{\rm GUT}

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    We derive renormalization group equations for neutrino masses, leptonic mixing angles and CP-violating phases running at energies above the seesaw threshold, both in the Standard Model and in the Minimal Supersymmetric Standard Model extended with three right-handed neutrinos. With these equations, we carry out a systematic study of the radiative correction that may arise to neutrino parameters, via their renormalization group evolution from the electroweak scale (MZM_{\rm Z}) to the scale of Grand Unified theories (ΛGUT\Lambda_{\rm GUT}). We study in detail three typically interesting neutrino mass patterns: normal hierarchy, near degeneracy and inverted hierarchy. Magnitudes of possible corrections in each case are carefully investigated. We also emphasize the significance of CP-violating phases in controlling the evolution behavior of all neutrino parameters.Comment: 45 pages, 2 tables, 10 figures; a misplaced graph in Figure 6 correcte

    Hot Nuclear Matter : A Variational Approach

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    We develop a nonperturbative technique in field theory to study properties of infinite nuclear matter at zero temperature as well as at finite temperatures. Here we dress the nuclear matter with off-mass shell pions. The techniques of thermofield dynamics are used for finite temperature calculations. Equation of state is derived from the dynamics of the interacting system in a self consistent manner. The transition temperature for nuclear matter appears to be around 15 MeV.Comment: 16 pages, IP/BBSR/91-3

    Fast protocol for high frequency in vitro cloning of Banana (Musa acuminata) cv. Grande Naine

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    An investigation was conducted on Fast Protocol for High Frequency in vitro cloning of Banana (Musa acuminata) cv. Grande Naine at the Biotechnology-cum-Tissue Culture Center, OUAT, Bhubaneswar, during the year 2012. This has helped to determine the best media compositions for shoot multiplication and rooting of cv. Grande Naine, so as to get optimum results with a minimized cost of production. MS medium supplemented with 4.0 mg/1 Benzylaminopurine (BAP) and 2.0 mg/1 Kinetin gave the highest number of shoot/explants (11.33) in 30 days. However, MS medium when supplemented with 6.0 mg/1 BAP produced a maximum number of leaves (19.07) with a maximum height 2.73 cm. Among various concentrations of indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) and naphthaleneacetic acid (NAA) for rooting. Half MS medium supplemented with 1.0 mg/1 IBA was found to be ideal for early rooting and producing more number of roots in 21 days. However, MS basal medium was found to be the best treatment to support the formation of long roots. This protocol can be very useful to the future research worker and as well as entrepreneurs for mass production of banana (Musa acuminata) cv. Grande Naine
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