124 research outputs found

    Reduction of Vector and Axial--Vector Fields in a Bosonized Nambu--Jona--Lasinio Model

    Full text link
    We derive the effective action for pseudoscalar mesons by integrating out vector and axial--vector collective fields in the generating functional of the bosonized NJL--model. The corresponding modifications of the nonlinear effective Lagrangian and the bosonized currents, arising at O(p4)O(p^4), are discussed.Comment: 30p. 1 fig. on reques

    Radiative Kaon Decays and CPCP Violation

    Full text link
    The amplitudes of K→πγ∗→πe+e−K \rightarrow \pi \gamma^* \rightarrow \pi e^+e^- and K→ππγK \rightarrow \pi \pi \gamma decays have been calculated within chiral Lagrangian approach including higher-order derivative terms and meson loops. The selfconsistency of the simultaneous description of the experimental data on the nonleptonic and radiative kaon decays have been demonstrated. We estimate the effects of ``indirect'' and ``direct'' CPCP-violation in KL0→π0e+e−K^0_L \rightarrow \pi^0 e^+e^- decays and discuss CPCP-violating charge asymmetries in K±→π±π0γK^{\pm} \rightarrow \pi^{\pm} \pi^0 \gamma decays.Comment: 25 p., DESY 93-06

    On the p4p^4--corrections to K→3πK \to 3\pi decay amplitudes in nonlinear and linear chiral models

    Full text link
    The calculations of isotopic amplitudes and their results for the direct CPCP--violating charge asymmetry in K±→3πK^\pm \to 3\pi decays within the nonlinear and linear (σ\sigma--model) chiral Lagrangian approach are compared with each other. It is shown, that the latter, taking into account intermediate scalar resonances, does not reproduce the p4p^4--corrections of the nonlinear approach introduced by Gasser and Leutwyler, being saturated mainly by vector resonance exchange. The resulting differences concerning the CPCP violation effect are traced in some detail.Comment: 14 page

    Heat-Kernel Calculation of Quark Determinant and Computer Algebra

    Full text link
    In this paper there we describe the calculational background of deriving a strong meson Lagrangian from the Nambu--Jona-Lasinio quark model using the computer algebra systems FORM and REDUCE in recursive algorithms, based on the heat-kernel method for the calculation of the quark determinant.Comment: LATEX, 11 p., DESY 92-15
    • …
    corecore