add Xb to LL pm meson decay modes
Add the following decay modes
- Xib0 -> (Lambda0 -> p+ pi-)(Lambda0 -> p+ pi-) p- K+
- Xib0 -> (Lambda0 -> p+ pi-)(Lambda0 -> p+ pi-) p- D_s+
- Lambda_b0 -> (Lambda0 -> p+ pi-)(Lambda0 -> p+ pi-) p- K+
- Lambda_b0 -> (Lambda0 -> p+ pi-)(Lambda0 -> p+ pi-) p- D_s+
as sensitivity study for sexaquark searches which have same quarkcontent as 2 lambdas