Possible ${\Sigma }^{\ast }(1/2^{-})$ in the initial-state polarized $\gamma N\to K^{+}{\Sigma }^{\ast }(1385)\to K^{+}\pi \Lambda$ reaction near threshold

Abstract

By using an effective Lagrangian method, we study the effects of a newly proposed ${\Sigma }^{\ast }(1/2^{-})$ state with mass around 1380 MeV in the initial-state polarized $\gamma N\to K^{+}{\Sigma }^{\ast }(1385)\to K^{+}\pi \Lambda$ process near threshold. The theoretical predictions for the helicity cross sections ${\sigma }_{3/2}$, ${\sigma }_{1/2}$ as well as their ratios, and the angular distributions of $\pi$ in the $\pi \Lambda$ center-of-mass system are given. It is found that assuming ${\Sigma }^{\ast }(1/2^{-})$ exists or not, these physical quantities are distinctly different. So our results could be useful for the investigation of the existence of ${\Sigma }^{\ast }(1/2^{-})$ when the experimental data are available in the future.

Comments: version published in PRC, 16 pages, 5 figures, more comments added