Search for XYZ states in υ (1S) inclusive decays

Abstract

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