Study of two-photon decays of pseudoscalar mesons via J / ψ radiative decays
Not Available
Engineering topics
Publications and source records attributed to Gradl, W..
Not Available
Not Available
Not Available
Not Available
Not Available
Not Available
Not Available
Not Available
Not Available
Not Available
Not Available
Not Available
Not Available
Not Available
Not Available
Using a sample of 448.1×10 6 ψ(3686) events collected with the BESIII detector, a search for the isospin violating decay η c → π⁺π⁻π⁰ via ψ(3686) → γ η c is presented. No signal is observed, and the upper limit on B(ψ(3686) → γ η c ) × B( η c → π⁺π⁻π⁰) is determined to be 1.6 × 10 -6 at the 90% confidence level. In addition, a search for η (1405) → f 0 (980)π 0 in (3686) radiative decays is performed. No signal is observed, and the branching fraction B(ψ(3686) → γη(1405))×B( η (1405) → f 0 (980)π 0 ) × B(f 0 (980) → π⁺π⁻ is calculated to be less than 5.0 × 10 -7 at the 90% confidence level.
Using a sample of 1.31×10 9 J/ψ events collected with the BESIII detector at the BEPCII collider, we study the decays of J/ψ→ K S K L and K S K S . The branching fraction of J/ψ→ K S K L is determined to be B(J/ψ→ K S K L ) = (1:93 0:01 (stat:) 0:05 (syst:))×10 -4 , which signi cantly improves on previous measurements. No clear signal is observed for the J/ψ→ K S K S process, and the upper limit at the 95% con dence level for its branching fraction is determined to be B(J= ! K S K S ) < 1:4×10 -8 , which improves on the previous searches by 2 orders in magnitude and reaches the order of the Einstein-Podolsky-Rosen expectation.