Direct CP violation in semi-inclusive flavor-changing neutral current decays in the MSSM without $R-$parity

Abstract

Semi-inclusive decays, $\hlx$, are studied in the framework of the minimal supersymmetric standard model without $R-$parity, where $\qh$ ($\ql$) are the second or third (first or second) generation quarks with the same charge and $\xi$ is a vector meson formed by $q_j \qb_j$. The study is focused on the contributions of sfermions with $m_{\sf} < m_{\rm top}$. In this mass region, CP asymmetries in top decays can be induced by taking into account the decay-widths of the exchanged-bosons, while in light-quark decays it can be generated due to the long-distance effects. The contributions of sfermions also alter the branching-ratios destructively or constructively depend on the phases of complex couplings of the $R-$parity violation interactions.