Off-shell effects in the electromagnetic production of strangeness

Abstract

Previous approaches to the photo- and electro-production of strangeness off the proton, based upon effective hadronic Lagrangians, are extended here to incorporate the so called off-shell effects inherent to the fermions with spin >= 3/2. A formalism for intermediate-state, spin 3/2, nucleonic and hyperonic resonances is presented and applied to the processes $\gamma +p--->K^{+}+\Lambda$, for $E_{\gamma }^{lab}$ <= 2.5 GeV, $e+p--->e^{\prime }+K^{+}+\Lambda$, as well as the branching ratio for the crossed channel reaction $K^{-}+p--->\gamma +\Lambda$, with stopped kaons. The sensitivity, from moderate to significant, of various observables to such effects are discussed.

Comments: 38 pages in LaTeX2e-RevTeX + 8 postscript figures