Phenomenology of Σ+ → pl+l- and the structure of the weak non-leptonic Hamiltonian

The problem of the radiative non-leptonic weak baryon decays is reviewed in light of the new experimental findings. With the aim of exploring the structure of the weak non-leptonic Hamiltonian, we present a detailed phenomenological analysis of Σ+ → pl+l- transitions. Lower and upper limits for rates derivable with standard physics are determined as Γ(Σ+ → pe+e-)/Γ(Σ+ → pγ) ≥ 7.2 x 10-3 and 1/1210 < or approx. Γ(Σ+ → pμ+μ-)/Γ(Σ+ → pe+e-) < or approx. 1/120. From existing data on Σ+ → pe+e- we obtain limits on the values of the charge radius form factors vertical strokec1/b1vertical stroke < or approx. 5; vertical strokec2/b1vertical stroke < or approx. 10, where the magnetic form factor is given by the Σ+ → pγ decay as b1(0) = 6.9±0.9 MeV. The short distance contribution of the QCD corrected single quark s → dγ transition is shown not to play a dominant role in these decays. (orig.)