7,336 research outputs found

    Threshold Effects on Quasi-degenerate Neutrinos with High-scale Mixing Unification

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    We consider threshold effects on neutrino masses and mixings in a recently proposed model for understanding large solar and atmospheric mixing angles using radiative magnification for the case of quasi-degenerate neutrinos. We show that the magnitude of the threshold effects is sufficient to bring concordance between the predictions of this model and latest data from KamLAND{\rm KamLAND} and SNO{\rm SNO} on observations of neutrino oscillations.Comment: Four pages, no figure

    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

    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

    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

    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

    Normal, Abby Normal, Prefix Normal

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    A prefix normal word is a binary word with the property that no substring has more 1s than the prefix of the same length. This class of words is important in the context of binary jumbled pattern matching. In this paper we present results about the number pnw(n)pnw(n) of prefix normal words of length nn, showing that pnw(n)=Ω(2ncnlnn)pnw(n) =\Omega\left(2^{n - c\sqrt{n\ln n}}\right) for some cc and pnw(n)=O(2n(lnn)2n)pnw(n) = O \left(\frac{2^n (\ln n)^2}{n}\right). We introduce efficient algorithms for testing the prefix normal property and a "mechanical algorithm" for computing prefix normal forms. We also include games which can be played with prefix normal words. In these games Alice wishes to stay normal but Bob wants to drive her "abnormal" -- we discuss which parameter settings allow Alice to succeed.Comment: Accepted at FUN '1

    Low-energy formulas for neutrino masses with tanβ\tan \beta-dependent hierarchy

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    Using radiative correction and seesaw mechanism,we derive analytic formulas for neutrino masses in SUSY unified theories exhibiting, for the first time, a new hierarchial relation among them.The new hierarchy is found to be quite significant especially for smaller values of tanβ\tan\beta.Comment: 10 pages,REVTEX, no figures,typographical errors rectifie

    Neutrino Mixings and Leptonic CP Violation from CKM Matrix and Majorana Phases

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    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 (0.3\simeq 0.3^{\circ}) and leptonic CP-violation parameter JCP(48)×105J_{CP} \simeq (4 - 8)\times 10^{-5} and θ13=3.5\theta_{13} = 3.5^{\circ}. 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 θ13=3.510\theta_{13} = 3.5^{\circ} - 10^{\circ} and JCP|J_{CP}| as large as 0.020.040.02-0.04 which are accessible to long baseline neutrino oscillation experiments.Comment: 15 pages and 10 figures, typo correcte
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