$N^{\ast }$ Production from $e^{+}{e}^{-}$ Annihilations

Abstract

Up to now, the $N^{\ast }$ production from $e^{+}{e}^{-}$ annihilations has been studied only around charmonium region. Charmonium decays to $N^{\ast }$s are analogous to (time-like) EM form factors in that the charm quark annihilation provides a nearly pointlike (ggg) current. Complementary to other sources, such as $\pi N$, $eN$ and $\gamma N$ reactions, this new source for $N^{\ast }$ spectroscopy has a few advantages, such as an isospin filter and a low spin filter. The experimental results on $N^{\ast }$ from $e^{+}{e}^{-}$ annihilations and their phenomenological implications are reviewed. Possible new sources on $N^{\ast }$ production from $e^{+}{e}^{-}$ annihilations are discussed.

Comments: 7 pages, 4 figures. Contribution to the proceedings of the 11th International Workshop on the Physics of Excited Nucleons, 20-23 August 2017, University of South Carolina, Columbia, SC, USA