Spontaneously Broken Horizontal SU(2) Gauge Symmetry and the I = 1/2 Rule

Abstract

We propose a new model for weak interactions which is based on the two-sextet scheme of flavor quarks and the spontaneous breaking of horizontal SU(2) gauge symmetry. It is shown that this model can explain theilI=I/2 rule. The existence of superheavy quarks and weak bosons is necessary. As is well known, the LlI=1/2 rule is the long standing puzzle in the nonleptonic weak decays. In fact, the standard electroweak theoryl) itself does not satisfy this property though it has extensively been studied, and proved successful. Hence it is an intriguing problem to clarify its origin and this gap.' After the success 2 ) of the perturbative QCD theory, interesting attempts 3 ),4) have been made to explain the LlI = 1/2 rule by combining the standard weak theory and the QCD theory. The hard QCD effects,5),6) however, seem insufficient to give the LlI = 1/2 rule. To resolve this, soft QCD effects 7 ) are also supposed to supplement the hard ones. In particular, it is required to enhance an sod transition;8) however, it appears still open to understand the expected QCD effects in a unique way. In this paper, therefore, we discuss a possibility of new weak interactions to give the dynamical large LlI = 1/2 transition. Let us now begin by taking notice of the DGG approach 9 ) to the LlI=1/2 rule.