Search for K_S K_L in psi'' decays

TL;DR

This paper reports a search for the decay of psi'' into K_S K_L using BESII data, setting an upper limit on the branching fraction and comparing it with theoretical predictions based on charmonium mixing models.

Contribution

It provides the first experimental upper limit on B(psi''--> K_S K_L) and tests the S- and D-wave mixing model of charmonia.

Findings

Upper limit of B(psi''--> K_S K_L) < 2.1×10^{-4} at 90% C.L.

Comparison with S- and D-wave mixing model predictions.

Supports or constrains charmonium decay models.

Abstract

K_S K_L from psi'' decays is searched for using the psi'' data collected by BESII at BEPC, the upper limit of the branching fraction is determined to be B(psi''--> K_S K_L) < 2.1\times 10^{-4} at 90% C. L. The measurement is compared with the prediction of the S- and D-wave mixing model of the charmonia, based on the measurements of the branching fractions of J/psi-->K_S K_L and psi'-->K_S K_L.