Factorization Contributions and the Breaking of the $\Delta I=1/2$ Rule in Weak $\Lambda N\rho$ and $\Sigma N\rho$ Couplings

Abstract

We compute the modified factorization contributions to the $\Lambda \to N\rho$ and $\Sigma \to N\rho$ couplings and demonstrate that these contributions naturally include $\Delta I=3/2$ terms which are comparable ($\simeq 0.4$ to $-0.8$ times) in magnitude to the corresponding $\Delta I=1/2$ terms. As a consequence, we conclude that models which treat vector meson exchange contributions to the weak conversion process $\Lambda N\to NN$ assuming such weak couplings to satisfy the $\Delta I=1/2$ rule are unlikely to be reliable.

Comments: 13 pages, uses REVTEX Entire manuscript available as a ps file at http://www.physics.adelaide.edu.au/theory/home.html . Also available via anonymous ftp at ftp://adelphi.adelaide.edu.au/pub/theory/ADP-95-5.T172.ps To appear in Physical Review C