Observation of charmed strange meson pair production in ϒ (2S) decays and in e e- annihilation at s =10.52 GeV

Abstract

We observe the process ϒ(2S)→Ds(∗)+DsJ- and continuum production e+e-→Ds(∗)+DsJ- at s=10.52 GeV (and their charge conjugates) using the data samples collected by the Belle detector at KEKB, where DsJ- is Ds1(2536)- or Ds2∗(2573)-. Both DsJ- states are identified through their decay into K̄D¯(∗). We measure the products of branching fractions B(ϒ(2S)→Ds(∗)+DsJ-)B(DsJ-→K̄D¯(∗)) and the Born cross sections σBorn(e+e-→Ds(∗)+DsJ-)B(DsJ-→K̄D¯(∗)), and then compare the ratios R1B(ϒ(2S)→Ds(∗)+DsJ-)/B(ϒ(2S)→μ+μ-) for ϒ(2S) decays and R2σBorn(e+e-→Ds(∗)+DsJ-)/σBorn(e+e-→μ+μ-) for continuum production. We obtain R1/R2=9.7±2.3±1.1, 6.8±2.1±0.8, 10.2±3.3±2.5, and 3.4±2.1±0.8 for the Ds+Ds1(2536)-, Ds∗+Ds..