Open charm scenarios

الأصل · EN

We discuss possibilities of identifying open charm effects in direct production processes, and propose that direct evidence for the open charm effects can be found in e+ e-→ J/ψπ⁰. A unique feature with this process is that the DD*+c.c. open channel is located in a relatively isolated energy, i.e. 3.876 GeV, which is sufficiently far away from the known charmonia ψ(3770) and ψ(4040). Due to the dominance of the isospin-0 component at the charmonium energy region, an enhanced model-independent cusp effect between the thresholds of D⁰D*⁰+c.c. and D+ D*⁻+c.c. can be highlighted. An energy scan over this energy region in the e+e- annihilation reaction can help us to understand the nature of X(3900) recently observed by Belle Collaboration in e+ e-→ DD+c.c., and establish the open charm effects as an important non-perturbative mechanism in the charmonium energy region.