Study of $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}J/\psi$ and Observation of a Charged Charmonium-like State at Belle

Belle Collaboration, Z. Q. Liu, C. P. Shen +185

The cross section for $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}J/\psi$ between 3.8 GeV and 5.5 GeV is measured with a 967 fb${}^{-1}$ data sample collected by the Belle detector at or near the ${\rm Y}(nS)$ ($n…