Search for exclusive multibody non- decays at the resonance

Towards a dynamical understanding of the non-DD decay of psi(3770)

We investigate the psi(3770) non-DD decays into VP, where V and P denote vector and pseudoscalar mesons, respectively, via Okubo-Zweig-Iizuka-rule-evading intermediate meson rescatterings in an effective Lagrangian theory. By identifying the leading meson loop transitions and constraining the model parameters with the available experimental data for psi(3770)-->J/psieta, phieta, and rhopi, we succeed in making a quantitative prediction for all psi(3770)-->VP with BRVP from 0.41% to 0.64%. It indicates that the Okubo-Zweig-Iizuka-rule-evading long-range interactions play a role in psi(3770) strong decays, and could be a key towards a full understanding of the mysterious psi(3770) non-DD decay mechanism.

QCD prediction for the non-DD[over ] annihilation decay of psi(3770)

To clarify the marked difference between BES and CLEO measurements on the non-DD[over ] decays of the psi(3770), a 1(3)D1-dominated charmonium, we calculate the annihilation decay of psi(3770) in nonrelativistic QCD. By introducing the color-octet contributions, the results are free from infrared divergences. The color-octet matrix elements are estimated by solving the evolution equations. The S-D mixing effect is found to be very small. With m_{c}=1.5+/-0.1 GeV, our result is Gamma(psi(3770)-->light hadrons)=467(+338);(-187) keV. For mc=1.4 GeV, together with the observed hadronic transitions and E1 transitions, the non-DD[over ] decay branching ratio of psi(3770) could reach about 5%. Our results do not favor the results of either the BES or the CLEO Collaborations, and further experimental tests are urged.

Anomalous line shape of the cross section for e{+}e{-}--> hadrons in the center-of-mass energy region between 3.650 and 3.872 GeV

We observe an obvious anomalous line shape of the e;{+}e;{-}--> hadrons total cross sections in the energy region between 3.700 and 3.872 GeV. It is inconsistent with the explanation for only one simple psi(3770) resonance with a statistical significance of 7sigma. The anomalous line shape may be explained by two possible enhancements of the inclusive hadron production near the center-of-mass energies of 3.764 and 3.779 GeV, indicating that either there is likely a new structure in addition to the psi(3770) resonance around 3.773 GeV, or there are some physics effects reflecting the DD[over ] production dynamics.