Study of $\bar{\hat{I}}›$-$p$ Annihilation into Light Mesons

Abstract

The annihilation of $\bar{\hat{I}}›$-$p$ into light mesons is studied using $(10.087\pm 0.044)\times 10^9$ $J/\ddot{I}ˆ$ events collected with the BESIII detector at the BEPCII storage ring. The $\bar{\hat{I}}›$ baryons are produced in the process $J/\ddot{I}ˆ\to \hat{I}›\bar{\hat{I}}›$ and interact with the protons in the hydrogen nuclei in the cooling oil of the beam pipe. The reactions $\bar{\hat{I}}›p\to K^{+}\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ and $K^{+}2\ddot{I}{€}^{+}2\ddot{I}{€}^{-}$ are observed for the first time, evidence for the reaction $\bar{\hat{I}}›p\to K_S^{0}2\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ is found, and no significant signals are seen for the reactions $\bar{\hat{I}}›p\to K_S^0\ddot{I}{€}^{+}$, $K^{+}3\ddot{I}{€}^{+}3\ddot{I}{€}^{-}$ and $2K^{+}{K}^{-}$. The cross sections of these reactions are also measured at $P_{\bar{\hat{I}}›}\approx 1.074$ GeV/$c$. Furthermore, no significant structures are observed in the combinations of the final state particles for these reactions. The annihilation of $\bar{\hat{I}}›$-$p$ into light mesons presents the similar behavior as $\bar{n}$-$p$ reactions in this energy region. These new measurements will serve as important inputs for the theoretical understanding of the antihyperon-nucleon interaction, and further contribute to understanding antibaryon-baryon interaction in a unified perspective.

9 pages, 2 figures