The first search for double charged charmoniumlike state production in ϒ(1S) and ϒ(2S) decays and in e+e− annihilation at s=10.52, 10.58, and 10.867 GeV is conducted using data collected with the Belle detector at the...
详细信息
The first search for double charged charmoniumlike state production in ϒ(1S) and ϒ(2S) decays and in e+e− annihilation at s=10.52, 10.58, and 10.867 GeV is conducted using data collected with the Belle detector at the KEKB asymmetric energy electron-positron collider. No significant signals are observed in any of the studied modes, and the 90% credibility level upper limits on their product branching fractions in ϒ(1S) and ϒ(2S) decays [B(ϒ(1S,2S)→Zc+Zc(′)−)×B(Zc+→π++cc¯) (cc¯=J/ψ, χc1(1P), ψ(2S))] and the product of Born cross section and branching fraction for e+e−→Zc+Zc(′)− (σ(e+e−→Zc+Zc(′)−)×B(Zc+→π++cc¯)) at s=10.52, 10.58, and 10.867 GeV are determined. Here, Zc refers to the Zc(3900) and Zc(4200) observed in the πJ/ψ final state, the Zc1(4050) and Zc2(4250) in the πχc1(1P) final state, and the Zc(4050) and Zc(4430) in the πψ(2S) final state.
This paper presents a search for the rare flavor-changing neutral current process B0→K*0τ+τ− using data taken with the Belle detector at the KEKB asymmetric energy e+e− collider. The analysis is based on the entire...
详细信息
This paper presents a search for the rare flavor-changing neutral current process B0→K*0τ+τ− using data taken with the Belle detector at the KEKB asymmetric energy e+e− collider. The analysis is based on the entire ϒ(4S) resonance data sample of 711 fb−1, corresponding to 772×106BB¯ pairs. In our search we fully reconstruct the companion B meson produced in the process e+e−→ϒ(4S)→BB¯ from its hadronic decay modes, and look for the decay B0→K*0τ+τ− in the rest of the event. No evidence for a signal is found. We report an upper limit on the branching fraction B(B0→K*0τ+τ−)<3.1×10−3 at 90% confidence level. This is the first direct limit on B(B0→K*0τ+τ−).
暂无评论