Partial wave analyses of $\ddot{I}ˆ(3686)\to p\bar{p}\ddot{I}{€}^0$ and $\ddot{I}ˆ(3686)\to p\bar{p}\hat{I}\cdot$

Abstract

Using a sample of $(2712\pm 14)\times 10^6$ $\ddot{I}ˆ(3686)$ events collected with the BESIII detector, we perform partial wave analyses of the decays $\ddot{I}ˆ(3686)\to p\bar{p}\ddot{I}{€}^0$ and $\ddot{I}ˆ(3686)\to p\bar{p}\hat{I}\cdot$. The branching fractions of $\ddot{I}ˆ(3686)\to p\bar{p}\ddot{I}{€}^0$ and $\ddot{I}ˆ(3686)\to p\bar{p}\hat{I}\cdot$ are determined to be $(133.9\pm 11.2\pm 2.3)\times 10^{-6}$ or $(183.7\pm 13.7\pm 3.2)\times 10^{-6}$ and $(61.5\pm 6.5\pm 1.1)\times 10^{-6}$ or $(84.4\pm 6.9\pm 1.4)\times 10^{-6}$, respectively, where the two solutions are caused by an ambiguous phase angle between resonant and continuum processes. Several well-established $N^{\ast }$ states are observed in the $p\ddot{I}{€}^0$ and $p\hat{I}\cdot$ systems, and the corresponding branching fractions are measured. The ratio of decay widths $\hat{I}{“}_{N(1535)\to N\hat{I}\cdot }/\hat{I}{“}_{N(1535)\to N\ddot{I}€}$ is determined to be $0.99\pm 0.05\pm 0.19$.

19 pages, 7 figures, Accepted by PRD