1,206 research outputs found

    Unified parametrization of quark and lepton mixing matrices in tri-bimaximal pattern

    Full text link
    Parametrization of the quark and lepton mixing matrices is the first attempt to understand the mixing of fermions. In this work, we parameterize the quark and lepton matrices with the help of quark-lepton complementarity (QLC) in a tri-bimaximal pattern of lepton mixing matrix. In this way, we combine the parametrization of the two matrices with each other. We apply this new parametrization to several physical quantities, and show its simplicity in the expression of, e.g., the Jarlskog parameter of CP violation.Comment: 12 latex page

    Photon-meson transition form factors of light pseudoscalar mesons

    Full text link
    The photon-meson transition form factors of light pseudoscalar mesons π0\pi ^{0}, η\eta, and η′\eta ^{\prime} are systematically calculated in a light-cone framework, which is applicable as a light-cone quark model at low Q2Q^{2} and is also physically in accordance with the light-cone pQCD approach at large Q2Q^{2}. The calculated results agree with the available experimental data at high energy scale. We also predict the low Q2Q^{2} behaviors of the photon-meson transition form factors of π0\pi ^{0}, η\eta and η′\eta ^{\prime }, which are measurable in e+A(Nucleus)→e+A+Me+A({Nucleus})\to e+A+M process via Primakoff effect at JLab and DESY.Comment: 22 Latex pages, 7 figures, Version to appear in PR

    Experimental determination of the Weiss temperature of Mn12_{12}-ac and Mn12_{12}-ac-MeOH

    Get PDF
    We report measurements of the susceptibility in the temperature range from 3.53.5 K to 6.06.0 K of a series of Mn12_{12}-ac and Mn12_{12}-ac-MeOH samples in the shape of rectangular prisms of length lcl_c and square cross-section of side lal_a. The susceptibility obeys a Curie-Weiss Law, χ=C/(T−θ)\chi=C/(T-\theta), where θ\theta varies systematically with sample aspect ratio. Using published demagnetization factors, we obtain θ\theta for an infinitely long sample corresponding to intrinsic ordering temperatures Tc≈0.85T_c \approx 0.85 K and ≈0.74\approx 0.74 K for Mn12_{12}-ac and Mn12_{12}-ac-MeOH, respectively. The difference in TcT_c for two materials that have nearly identical unit cell volumes and lattice constant ratios suggests that, in addition to dipolar interactions, there is a non-dipolar (exchange) contribution to the Weiss temperature that differs in the two materials because of the difference in ligand molecules.Comment: 4.5 page

    Unified triminimal parametrizations of quark and lepton mixing matrices

    Full text link
    We present a detailed study on triminimal parametrizations of quark and lepton mixing matrices with different basis matrices. We start with a general discussion on the triminimal expansion of the mixing matrix and on possible unified quark and lepton parametrization using quark-lepton complementarity (QLC). We then consider several interesting basis matrices and compare the triminimal parametrizations with the Wolfenstein-like parametrizations. The usual Wolfenstein parametrization for quark mixing is a triminimal expansion around the unit matrix as the basis. The corresponding QLC lepton mixing matrix is a triminimal expansion around the bimaximal basis. Current neutrino oscillation data show that the lepton mixing matrix is very well represented by the tri-bimaximal mixing. It is natural to take it as an expanding basis. The corresponding zeroth order basis for quark mixing in this case makes the triminimal expansion converge much faster than the usual Wolfenstein parametrization. The triminimal expansion based on tri-bimaximal mixing can be converted to the Wolfenstein-like parametrizations discussed in the literature. We thus have a unified description between different kinds of parametrizations for quark and lepton sectors: the standard parametrizations, the Wolfenstein-like parametrizations, and the triminimal parametrizations.Comment: 14 latex pages, no figure, to appear in PR

    q-deformed Supersymmetric t-J Model with a Boundary

    Full text link
    The q-deformed supersymmetric t-J model on a semi-infinite lattice is diagonalized by using the level-one vertex operators of the quantum affine superalgebra Uq[sl(2∣1)^]U_q[\hat{sl(2|1)}]. We give the bosonization of the boundary states. We give an integral expression of the correlation functions of the boundary model, and derive the difference equations which they satisfy.Comment: LaTex file 18 page

    Pion-photon and photon-pion transition form factors in light-cone formalism

    Full text link
    We derive the minimal Fock-state expansions of the pion and the photon wave functions in light-cone formalism, then we calculate the pion-photon and the photon-pion transition form factors of γ∗π0→γ\gamma ^{\ast}\pi ^{0}\to \gamma and γ∗γ→π0\gamma ^{\ast}\gamma \to \pi ^{0} processes by employing these quark-antiquark wave functions of the pion and the photon. We find that our calculation for the γ∗γ→π0\gamma ^{\ast}\gamma \to \pi ^{0} transition form factor agrees with the experimental data at low and moderately high energy scale. Moreover, the physical differences and inherent connections between the transition form factors of γ∗π0→γ\gamma ^{\ast}\pi ^{0}\to \gamma and γ∗γ→π0 \gamma ^{\ast}\gamma \to \pi ^{0} have been illustrated, which indicate that these two physical processes are intrinsically related. In addition, we also discuss the π0→γγ\pi ^{0}\to \gamma \gamma form factor and the decay width Γ(π→γγ) \mathit{\Gamma}(\pi \to \gamma \gamma) at Q2=0Q^{2}=0.Comment: 20 pages, 2 figure

    Expanding Insight into Asymmetric Palladium-Catalyzed Allylic Alkylation of N-Heterocyclic Molecules and Cyclic Ketones

    Get PDF
    Eeny, meeny, miny … enaminones! Lactams and imides have been shown to consistently provide enantioselectivities substantially higher than other substrate classes previously investigated in the palladium-catalyzed asymmetric decarboxylative allylic alkylation. Several new substrates have been designed to probe the contributions of electronic, steric, and stereoelectronic factors that distinguish the lactam/imide series as superior alkylation substrates (see scheme). These studies culminated in marked improvements on carbocyclic allylic alkylation substrates

    Development of Complement Factor H-Based Immunotherapeutic Molecules in Tobacco Plants Against Multidrug-Resistant Neisseria gonorrhoeae

    Get PDF
    Novel therapeutics against the global threat of multidrug-resistant Neisseria gonorrhoeae are urgently needed. Gonococci possess several mechanisms to evade killing by human complement, including binding of factor H (FH), a key inhibitor of the alternative pathway. FH comprises 20 short consensus repeat (SCR) domains organized in a head-to-tail manner as a single chain. N. gonorrhoeae binds two regions in FH; domains 6 and 7 and domains 18 through 20. We designed a novel anti-infective immunotherapeutic molecule that fuses domains 18-20 of FH containing a D-to-G mutation in domain 19 at position 1119 (called FH*) with human IgG1 Fc. FH*/Fc retained binding to gonococci but did not lyse human erythrocytes. Expression of FH*/Fc in tobacco plants was undertaken as an alternative, economical production platform. FH*/Fc was expressed in high yields in tobacco plants (300-600 mg/kg biomass). The activities of plant- and CHO-cell produced FH*/Fc against gonococci were similar in vitro and in the mouse vaginal colonization model of gonorrhea. The addition of flexible linkers [e.g., (GGGGS)2 or (GGGGS)3] between FH* and Fc improved the bactericidal efficacy of FH*/Fc 2.7-fold. The linkers also improved PMN-mediated opsonophagocytosis about 11-fold. FH*/Fc with linker also effectively reduced the duration and burden of colonization of two gonococcal strains tested in mice. FH*/Fc lost efficacy: i) in C6(-/-) mice (no terminal complement) and ii) when Fc was mutated to abrogate complement activation, suggesting that an intact complement was necessary for FH*/Fc function in vivo. In summary, plant-produced FH*/Fc represent promising prophylactic or adjunctive immunotherapeutics against multidrug-resistant gonococci

    Determinant representations of scalar products for the open XXZ chain with non-diagonal boundary terms

    Full text link
    With the help of the F-basis provided by the Drinfeld twist or factorizing F-matrix for the open XXZ spin chain with non-diagonal boundary terms, we obtain the determinant representations of the scalar products of Bethe states of the model.Comment: Latex file, 28 pages, based on the talk given by W. -L. Yang at Statphys 24, Cairns, Australia, 19-23 July, 201
    • …
    corecore