A Supersymmetric $S{p}_L\times U_Y(1)$ Model

Abstract

A supersymmetric $S{p}_L(6)\times U_Y(1)$ model (SUSY $Sp(6)$) is proposed as an extension of the standard electroweak model. The model is applied in a phenomenological study of $B_d^0{\bar{B}}_d^0$ mixing. It is found that the supersymmetric (SUSY) partner ${\tilde{z}}^{\prime }$ of the extra $Z^{\prime }$ can significantly cancel the other contributions to bring the mixing parameter $x_d$ within the experimentally allowed range $0.57\stackrel{<}{\sim }{x}_d\stackrel{<}{\sim }0.77$ for a top mass of $158\stackrel{<}{\sim }{m}_t\stackrel{<}{\sim }194$ Gev. Other interesting and possibly novel features of flavor changing neutral currents (FCNC) in SUSY theories with horizontal gauge symmetries are pointed out.

Comments: to be published at the Il Nuovo Cimento A; uses FEYNMAN.tex; hard copy available from G. G. Blado (bladogg@cda.mrs.umn.edu) by regular mail upon e-mail requests