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arXiv · hep-ph/9806358

Exact Light-Cone Wavefunction Representation of Matrix Elements of Electroweak Current

S. J. Brodsky·D. S. Hwang
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Abstract

The matrix elements of electroweak currents which occur in exclusive decays of heavy hadrons are evaluated in the nonperturbative light-cone Fock representration. In general, each semileptonic exclusive decay amplitude receives two contributions, a diagonal $Δn = 0$ parton-number-conserving amplitude and a $Δn = -2$ contribution in which a quark and an antiquark from the initial hadron Fock state annihilate to the leptonic current. The general formalism can be used as a basis for systematic approximations to heavy hadron decay amplitudes such as hard perturbative QCD contributions. We illustrate the general formalism using a simple perturbative model of composite hadrons. Our analysis demonstrates the occurence of "zero-mode" endpoint contributions to matrix elements of the "bad" $j^-$ currents in the Drell-Yan frame when $q^+ \to 0$.

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S. J. Brodsky, D. S. Hwang. 1998-06-12. Exact Light-Cone Wavefunction Representation of Matrix Elements of Electroweak Current. https://doi.org/10.1016/s0550-3213(98)00807-4

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