Decays of Z Boson into Pseudoscalar Meson Pair of Different Flavours

Abstract

We analyse the process Z-zero to M1 M2, where M1 and M2 are pseudoscalar mesons with quark contents of q1 q-bar and q-bar q2 respectively. At the quark level, the process-zero to q1 q2-bar, where q1 and q2 are quarks of different flavours, receives contribution only from the Z-penguin. In order to fold the quark-level process to the hadronic process, we make the fundamental assumption that the vertex of type M q q-bar can be approximated by an effective constant gamma 5 coupling. With this assumption, estimates are obtained for the cross-sections for the following processes: Z-zero to K-minus pi-plus, Z-zero to B-minus K-plus.