Study of the decay D0→K¯0π−e+νe

We report a study of the decay D0→K̄0π-e+νe based on a sample of 2.93 fb-1 e+e- annihilation data collected at the center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider. The total branching fraction is determined to be B(D0→K̄0π-e+νe)=(1.434±0.029(stat.)±0.032(syst.))%, which is the most precise to date. According to a detailed analysis of the involved dynamics, we find this decay is dominated with the K∗(892)- contribution and present an improved measurement of its branching fraction to be B(D0→K∗(892)-e+νe)=(2.033±0.046(stat.)±0.047(syst.))%. We further access their hadronic form-factor ratios for the first time as rV=V(0)/A1(0)=1.46±0.07(stat.)±0.02(syst.) and r2=A2(0)/A1(0)=0.67±0.06(stat.)±0.01(syst.). In addition, we observe a significant K̄0π- S-wave component accounting for (5.51±0.97(stat.)±0.62(syst.))% of the total decay rate

Observation of chi(cJ) -> Lambda(Lambda)over-bar(eta)

By analyzing (448.1 +/- 2.9) x 10(6) psi(3686) events collected with the BESIII detector operating at the BEPCII collider, the decays of chi(cJ) -> Lambda(Lambda) over bar (eta) (J = 0, 1, and 2) are observed for the first time with statistical significances of 13.9 sigma, 6.7 sigma, and 8.2 sigma, respectively. The product branching fractions of psi(3686) -> gamma chi(cJ) and chi(cJ) -> Lambda(Lambda) over bar (eta) are measured. Dividing by the world averages of the branching fractions of psi(3686) -> gamma chi(cJ), the branching fractions of chi(cJ) -> Lambda(Lambda) over bar (eta) decays are determined to be (2.31 +/- 0.30 +/- 0.21) x 10(-4), (5.86 +/- 1.38 +/- 0.68) x 10(-5), and (1.05 +/- 0.21 +/- 0.15) x 10(-4) for J = 0, 1 and 2, respectively, where the first uncertainties are statistical and the second systematic