Measurement of A baryon polarization in e(+) e(-) -> Lambda(Lambda)over-bar at root s=3.773 GeV

Using a data sample of psi(3770) events collected with the BESIII detector at BEPCII corresponding to an integrated luminosity of 2.9 fb-1, we report a measurement of A spin polarization in e+ e- -> Lambda(Lambda) over bar at = root s = 3.773 GeV. The significance of polarization is found to be 2 sigma including the systematic uncertainty, which implies a zero phase between the transition amplitudes of the Lambda(Lambda) over bar helicity states. This phase can be interpreted in terms of psionic form factors, and is determined to be Delta Phi(Psi) = Phi(Psi)(E) - Phi(Psi)(M) = (71(-46)(+66) +/- 5)degrees. Similarly, the ratio between the form factors is found to be R-psi = vertical bar G(E)(Psi)/G(M)(Psi)vertical bar = 0.48(-0.35)(+0.21) +/- 0.03. The first uncertainties are statistical and the second systematic

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