2,718 research outputs found

    Quantum anomaly of the transverse Ward-Takahashi relation for the axial-vector vertex

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    We study the possible quantum anomaly for the transverse Ward-Takahashi relations in four dimensional gauge theories based on the method of computing the axial-vector and the vector current operator equations. In addition to the well-known anomalous axial-vector divergence equation (the Adler-Bell-Jackiw anomaly), we find the anomalous axial-vector curl equation, which leads to the quantum anomaly of the transverse Ward-Takahashi relation for the axial-vector vertex. The computation shows that there is no anomaly for the transverse Ward-Takahashi relation for the vector vertex.Comment: 6 pages, LaTe

    The frizzled pathway regulates the development of arista laterals.

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    BACKGROUND: The frizzled pathway in Drosophila has been studied intensively for its role in the development of planar polarity in wing hairs, thoracic bristles and ommatidia. Selected cells in the arista (the terminal segment of the antenna) elaborate a lateral projection that shares characteristics with both hairs and bristles. RESULTS: We found that mutations in putative downstream members of the frizzled pathway, such as inturned resulted in multipled and split laterals, but no obvious polarity defects. Mutations in upstream genes such as frizzled did not show an adult arista phenotype. When we examined lateral development in the mutants we found that, as is the case on the wing for hair development the frizzled pathway regulated the subcellular location for lateral initiation. However, on the arista an altered location for lateral initiation did not result in altered polarity, as did an altered site for hair initiation. The regulation of lateral development involved the preferential accumulation of Frizzled protein at the distal edges of lateral cells much as is seen on the wing. In contrast to the situation in wing cells, in arista cells the location for lateral initiation was close to but did not overlap the region of preferential Frizzled accumulation. CONCLUSION: Our data indicates that a modified version of the frizzled pathway regulates arista development. We conclude that the lack of a polarity defect in mutant aristae is likely to be a consequence of inherent differences in the cell biology of wing hair and lateral forming cells

    Di-hadron azimuthal correlation and Mach-like cone structure in parton/hadron transport model

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    In the framework of a multi-phase transport model (AMPT) with both partonic and hadronic interactions, azimuthal correlations between trigger particles and associated scattering particles have been studied by the mixing-event technique. The momentum ranges of these particles are 3<pTtrig<63< p^{trig}_T< 6 GeV/cc and 0.15<pTassoc<30.15< p_{T}^{assoc} < 3 GeV/cc (soft), or 2.5<pTtrig<2.5<p^{trig}_T< 4 GeV/cc and 1<pTassoc<2.51< p_{T}^{assoc} < 2.5 GeV/cc (hard) in Au + Au collisions at sNN\sqrt{s_{NN}} = 200 GeV. A Mach-like structure has been observed in correlation functions for central collisions. By comparing scenarios with and without parton cascade and hadronic rescattering, we show that both partonic and hadronic dynamical mechanisms contribute to the Mach-like structure of the associated particle azimuthal correlations. The contribution of hadronic dynamical process can not be ignored in the emergence of Mach-like correlations of the soft scattered associated hadrons. However, hadronic rescattering alone cannot reproduce experimental amplitude of Mach-like cone on away-side, and the parton cascade process is essential to describe experimental amplitude of Mach-like cone on away-side. In addition, both the associated multiplicity and the sum of pTp_{T} decrease, whileas the increases, with the impact parameter in the AMPT model including partonic dynamics from string melting scenario.Comment: 9 pages, 5 figures; Physics Letters B 641, 362-367 (2006

    Application of SH and Lamb Wave Emat’s for Evaluation of Adhesive Joint in Thin Plate

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    The applicability of SH wave for the evaluation of adhesive joint in thin plate was studied. The advantages of the SH guided wave is that its displacement and stress are oriented parallel to the adhesive-adherent interface, and therefore, it can be used to evaluate interface properties. The experimental studies are focused on the relations between acoustic parameters and geometry conditions, the comparison of ultrasonic data and strength data of the joint, and the attenuation in different cases. The experiments were done on lap-shear samples and long samples. For excitation and reception of SH waves, non-contact electromagnetic transducers were used. An additional investigation was carried out using Lamb waves for the same sample parameters

    Neutrino mass induced radiatively by supersymmetric leptoquarks

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    We show how nonzero Majorana neutrino masses can be radiatively generated by extending the MSSM with leptoquark chiral multiplets without violating R-parity. It is found that, with these particles, the R-parity conservation does not imply lepton number conservation. Neutrino masses generated at a one-loop level are closely related to the down quark mass matrix. The ratio of neutrino mass-squared splittings Δmν2ν12/Δmν3ν22\Delta m^2_{\nu_2-\nu_1}/\Delta m^2_{\nu_3-\nu_2} obtained is naturally close to Δmsd2/Δmbs2103\Delta m^2_{s-d}/\Delta m^2_{b-s}\sim 10^{-3} which is in the right region required to explain both the atmospheric neutrino data and the MSW solutions for the solar neutrino data.Comment: 13 pages, one figure, more constraints added. To appear in Phys. Lett.

    Collapse models with non-white noises II: particle-density coupled noises

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    We continue the analysis of models of spontaneous wave function collapse with stochastic dynamics driven by non-white Gaussian noise. We specialize to a model in which a classical "noise" field, with specified autocorrelator, is coupled to a local nonrelativistic particle density. We derive general results in this model for the rates of density matrix diagonalization and of state vector reduction, and show that (in the absence of decoherence) both processes are governed by essentially the same rate parameters. As an alternative route to our reduction results, we also derive the Fokker-Planck equations that correspond to the initial stochastic Schr\"odinger equation. For specific models of the noise autocorrelator, including ones motivated by the structure of thermal Green's functions, we discuss the qualitative and qantitative dependence on model parameters, with particular emphasis on possible cosmological sources of the noise field.Comment: Latex, 43 pages; versions 2&3 have minor editorial revision

    A Note on Transverse Axial Vector and Vector Anomalies in U(1) Gauge Theories

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    The transverse axial vector and vector anomalies in four-dimensional U(1) gauge theories studied in [10] is reexamined by means of perturbative methods. The absence of transverse anomalies for both axial vector and vector current is verified. We also show that the Pauli-Villars regularization and dimensional regularization give the same result on the transverse anomaly of both axial vector and vector current.Comment: Revtex4, 8 pages, two figures. Largely revised, using the Pauli-Villars regularization instead of dimensional regularization in the main proof. Final form to be published in Physics Letters

    Additional symmetries of constrained CKP and BKP hierarchies

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    The additional symmetries of the constrained CKP (cCKP) and BKP (cBKP) hierarchies are given by their actions on the Lax operators, and their actions on the eigenfunction and adjoint eigenfunction {Φi,Ψi}\{\Phi_i,\Psi_i \} are presented explicitly. Furthermore, we show that acting on the space of the wave operator, k\partial_k^* forms new centerless W1+cCW^{cC}_{1+\infty} and W1+cBW^{cB}_{1+\infty}-subalgebra of centerless W1+W_{1+\infty} respectively. In order to define above symmetry flows k\partial_k^* of the cCKP and cBKP hierarchies, two vital operators YkY_k are introduced to revise the additional symmetry flows of the CKP and BKP hierarchies.Comment: 14 pages, accepted by SCIENCE CHINA Mathematics(2010
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