Speaker
Description
This presentation delves into recent experimental measurements of charmonium decays, encompassing four independent measurements conducted at BESIII. 1) Based on 2.7 billion psi(3686) events collected with the BESIII detector at the BEPCII collider, we present the first evidence of chi_c0 → Lambda anti-Lambda phi decays and the first observation of chi_c1,2 → Lambda anti-Lambda phi decays, with significances of 4.5σ, 11.3σ, and 13.0σ, respectively; 2) Using the same data sample, we report the first observation of the decays chi_c0/1/2 → Lambda anti-Lambda omega with statistical significances of 11.7σ, 11.2σ, and 11.8σ. The branching fractions of these decays are determined, with no clear intermediate structures observed in the previous and current measurements; 3) The processes hc → gamma P(eta', eta, pi0) are studied with a sample of 2.7 billion ψ(3686) events collected by the BESIII detector at the BEPCII collider. The branching fractions of hc → gamma eta' and hc → gamma eta are measured, and an upper limit for hc → gamma pi0 is set; 4) Utilizing 9.0 fb−1 of e+e− collision data collected at center-of-mass energies from 4.178 to 4.278 GeV, we conduct the first search for the radiative transition chi_c1(3872) → gamma psi2(3823). No obvious signal is observed, and the upper limit at the 90% confidence level is determined.
