Search for X Y Z states in Υ ( 1 S ) inclusive decays

Abstract

The branching fractions of the Υ ( 1 S ) inclusive decays into final states with a J / ψ or a ψ ( 2 S ) are measured with improved precision to be B ( Υ ( 1 S ) → J / ψ + anything ) = ( 5.25 ± 0.13 ( stat ) ± 0.25 ( syst ) ) × 10 − 4 and B ( Υ ( 1 S ) → ψ ( 2 S ) + anything ) = ( 1.23 ± 0.17 ( stat ) ± 0.11 ( syst ) ) × 10 − 4 . The first search for Υ ( 1 S ) decays into X Y Z states that decay into a J / ψ or a ψ ( 2 S ) plus one or two charged tracks yields no significant signals for X Y Z states in any of the examined decay modes, and upper limits on their production rates in Υ ( 1 S ) inclusive decays are determined.