11,628 research outputs found

    Tripartite Neutrino Mass Matrix

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    The 3 X 3 Majorana neutrino mass matrix is written as a sum of 3 terms, i.e. M_nu = M_A + M_B + M_C, where M_A is proportional to the identity matrix and M_B and M_C are invariant under different Z_3 transformations. This M_nu is very suitable for understanding atmospheric and solar neutrino oscillations, with sin^2 (2 theta_atm) and tan^2 (theta_sol) fixed at 1 and 0.5 respectively, in excellent agreement with present data. It has in fact been proposed before, but only as an ansatz. This paper uncovers its underlying symmetry, thus allowing a complete theory of leptons and quarks to be constructed.Comment: 9 pages, no figur

    Softly Broken A_4 Symmetry for Nearly Degenerate Neutrino Masses

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    The leptonic Higgs doublet model of neutrino masses is implemented with an A_4 discrete symmetry (the even permutation of 4 objects or equivalently the symmetry of the tetrahedron) which has 4 irreducible representations: 1, 1', 1'', and 3. The resulting spontaneous and soft breaking of A_4 provides a realistic model of charged-lepton masses as well as a nearly degenerate neutrino mass matrix. Phenomenological consequences at and below the TeV scale are discussed.Comment: 11 pages, no figur

    Building Bonds on Teams: How Team Building Positively Impacts Young Athletes

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    Creating positive team culture in youth sports cultivates players who feel a part of a strong, close-knit organization which escalates their level of play and their desire to play. In addition to this, teams that have positive team culture develop on-field cohesion and trust that allows for sport strategy to be executed in a way that promotes success for the team as a whole. The methods used in coaching to promote this are focused on developing leadership, positive reinforcement, and other non-punitive measures. Scholarly research on this topic is sparse therefore this qualitative study attempts to add to the existing knowledge by analyzing information obtained during in-depth interviews with student-athlete

    New "Square Root" Model of Lepton Family Cyclic Symmetry

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    Following the newly formulated notion of form invariance of the neutrino mass matrix, a complete model of leptons is constructed. It is based on a specific unitary 3 X 3 matrix U in family space, such that U^2 is the simple discrete symmetry nu_e to -nu_e, nu_mu to nu_tau. Thus U also generates the cyclic group Z_4. The charged-lepton mass matrix is nearly diagonal while the neutrino mass matrix is of the form suitable for explaining maximal (large) mixing in atmospheric (solar) neutrino oscillations in the context of three nearly degenerate neutrino masses. Observable lepton flavor violation is predicted. Quarks may be treated in the same way as the charged leptons.Comment: 10 pages, no figur

    Tunable Cavity Optomechanics with Ultracold Atoms

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    We present an atom-chip-based realization of quantum cavity optomechanics with cold atoms localized within a Fabry-Perot cavity. Effective sub-wavelength positioning of the atomic ensemble allows for tuning the linear and quadratic optomechanical coupling parameters, varying the sensitivity to the displacement and strain of a compressible gaseous cantilever. We observe effects of such tuning on cavity optical nonlinearity and optomechanical frequency shifts, providing their first characterization in the quadratic-coupling regime.Comment: 4 pages, 5 figure

    Synthesis of new chiral organosulfur donors with hydrogen bonding functionality and their first charge transfer salts

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    The syntheses of a range of enantiopure organosulfur donors with hydrogen bonding groups are described including TTF related materials with two, four, six and eight hydroxyl groups and multiple stereogenic centres and a pair of chiral N-substituted BEDT-TTF acetamides. Three charge transfer salts of enantiopure poly-hydroxy-substituted donors are reported, including a 4:1 salt with the meso stereoisomer of the dinuclear [Fe2(oxalate)5 ]4- anion in which both cation and anion have chiral components linked together by hydrogen bonding, and a semiconducting salt with triiodide

    Thrombin is a novel regulator of hexokinase activity in mesangial cells

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    Thrombin is a novel regulator of hexokinase activity in mesangial cells.BackgroundHexokinase (HK) activity is fundamentally important to cellular glucose uptake and metabolism. Phorbol esters increase both HK activity and glucose utilization in cultured mesangial cells via a protein kinase C (PKC)- and extracellular signal-regulated kinases 1 and 2 (ERK1/2)-dependent mechanism. In adult kidneys, increased HK activity has been reported in both glomerular injury and in diabetes, but the mechanisms responsible for these changes are unknown. Thrombin, a known activator of both PKC and ERK1/2, is increased in the settings of renal injury and diabetes. Thus, thrombin may contribute to the observed changes in HK activity in vivo.MethodsThrombin and thrombin receptor agonists were tested for the ability to increase HK activity and glucose metabolism in murine mesangial (SV40 MES 13) cells. ERK1/2 activation was also evaluated in parallel. Thrombin inhibition (hirudins), PKC depletion, Ser-Thr kinase inhibition (H-7), MEK1/2 inhibition (PD98059), pertussis toxin (PTX), and general inhibitors of transcription or translation were then tested for the ability to attenuate these effects.ResultsThrombin (≥0.01 U/mL) mimicked the effect of phorbol esters, increasing HK activity 50% within 12 to 24 hours (P < 0.05). This effect was inhibited by hirudins, mimicked by thrombin receptor agonists, and accompanied by increased Glc utilization. H-7, PD98059, and general inhibitors of transcription or translation—but not PTX—prevented thrombin-induced HK activity at 24 hours. PKC depletion and PD98059 also blocked the associated phosphorylation and activation of ERK1/2.ConclusionsThrombin increases mesangial cell HK activity via a PTX-insensitive mechanism involving thrombin receptor activation, PKC-dependent activation of ERK1/2, and both ongoing gene transcription and de novo protein synthesis. As such, thrombin is a novel regulator of HK activity in mesangial cells and may play a role in coupling renal injury to metabolism

    How Neutrinos Get Mass and What Other Things May Happen Besides Oscillations

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    In this talk I address the theoretical issue of what new physics is required to make mν≠0m_\nu \neq 0. I then discuss what other things may happen besides neutrino oscillations. In particular I consider a possible new scenario of leptogenesis in R parity nonconserving supersymmetry.Comment: 7 pages including 1 figure, talk at WHEPP-

    Recalculation of Pion Compton Scattering in Perturbative QCD

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    We recalculated pion virtual Compton scattering in perturbative QCD in this paper. Our calculation avoids some deficiencies in existing literatures, and treats real Compton scattering as a limit case in which the mass of the virtual photon equals to zero. Expressions of the hard scattering amplitudes from 10 independent diagrams are given explicitly in the text. By comparing the effects of different distribution amplitudes on physical observables, we studied the self-consistence of pQCD calculation of this problem.Comment: 15 pages, 8 eps figs. accepted by Phys. Lett
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