1,206 research outputs found
Unified parametrization of quark and lepton mixing matrices in tri-bimaximal pattern
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
The photon-meson transition form factors of light pseudoscalar mesons , , and are systematically calculated in a
light-cone framework, which is applicable as a light-cone quark model at low
and is also physically in accordance with the light-cone pQCD approach
at large . The calculated results agree with the available experimental
data at high energy scale. We also predict the low behaviors of the
photon-meson transition form factors of , and , which are measurable in 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 Mn-ac and Mn-ac-MeOH
We report measurements of the susceptibility in the temperature range from
K to K of a series of Mn-ac and Mn-ac-MeOH samples in
the shape of rectangular prisms of length and square cross-section of
side . The susceptibility obeys a Curie-Weiss Law, ,
where varies systematically with sample aspect ratio. Using published
demagnetization factors, we obtain for an infinitely long sample
corresponding to intrinsic ordering temperatures K and
K for Mn-ac and Mn-ac-MeOH, respectively. The
difference in 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
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
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 . 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
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 and
processes by employing these
quark-antiquark wave functions of the pion and the photon. We find that our
calculation for the 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 and have been illustrated, which indicate that these
two physical processes are intrinsically related. In addition, we also discuss
the form factor and the decay width at .Comment: 20 pages, 2 figure
Expanding Insight into Asymmetric Palladium-Catalyzed Allylic Alkylation of N-Heterocyclic Molecules and Cyclic Ketones
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
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
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
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