We present a simple and straightforward method for relating the form factors in HQET, as defined by the covariant trace formalism, to the overlaps of the rest frame wave functions of the light degrees of freedom. We also point out several inconsistencies present in recent calculations of the radiative rare B decays, and also show how these can be fixed even within the framework of the non-relat...

Precise data on the neutron magnetic form factor Gmn have been obtained with measurements of the ratio of cross sections of D(e, en) and D(e, ep) up to momentum transfers of Q= 0.9 (GeV/c). Data with typical uncertainties of 1.5% are presented. These data allow for the first time to extract a precise value of the magnetic radius of the neutron.

A Poincaré covariant Faddeev equation, which describes baryons as composites of confined-quarks and -nonpointlike-diquarks, is solved to obtain masses and Faddeev amplitudes for the nucleon and ∆. The amplitudes are a component of a nucleon-photon vertex that automatically fulfills the Ward-Takahashi identity for on-shell nucleons. These elements are sufficient for the calculation of a quark co...

Germany bSchool of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ, UK cInstitut für Theoretische Physik, Universität Regensburg, 93040 Regensburg, Germany dSchool of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, UK eJohn von Neumann-Institut für Computing NIC / DESY, 15738 Zeuthen, Germany f Theoretical Physics Division, Department of Mathematical S...

We examine the use of phenomenological form factors in tree level amplitudes for meson photoproduction. Two common recipes are shown to be fundamentally incorrect. An alternate form consistent with gauge invariance and crossing symmetry is proposed. PACS numbers: 25.20.Lj, 13.60.Le, 11.40.-q, 11.80.Cr Typeset using REVTEX [email protected] [email protected]

Theoretical approaches to form factors of semileptonic decays are discussed in application to B → D + l + ν̄l decay. HQET AND SEMILEPTONIC FORM FACTORS ARKADY VAINSHTEIN Theoretical Physics Institute, University of Minnesota and Budker Institute of Nuclear Physics, Novosibirsk Theoretical approaches to form factors of semileptonic decays are discussed in application to B → D + l + ν̄l decay. 1 Ou...

The form factors of baryons have long been studied in electron scattering, and now we are here to discuss new opportunities that can come from an e+e− collider at moderate energies where exclusive cross sections may be measured. One can foresee measurements of the form factors of baryons in the timelike region. The richness of these measurements should be clear. We can in principle measure the ...