A combined study of the reactions $K^-p\rightarrow \Sigma^0\pi^0$, $\Lambda\pi^0$ and $\bar{ K}^0n$ at low energies is carried out with a chiral quark-model approach. Good descriptions of the experimental observations are obtained. The roles of the low-lying strangeness $S=-1$ hyperon resonances in these processes are carefully analyzed. We find that: (i) In the $K^-p\rightarrow \Sigma^0\pi^0$ process, both $\Lambda(1405)S_{ 01}$ and $\Lambda(1520)D_{ 03}$ play dominant roles. Significant contributions of $\Lambda(1670)S_{ 01}$ and $\Lambda(1690)D_{ 03}$ could be seen around their threshold; (ii) In the $K^-p\rightarrow \Lambda\pi^0$ process, some obvious evidence of $\Sigma(1775)D_{ 15}$ and $\Sigma(1750)S_{ 11}$ could be found. Some hints of $\Sigma(1620)S_{ 11}$ might exist in the reaction as well. $\Sigma(1750)S_{ 11}$ and $\Sigma(1620)S_{ 11}$ should correspond to the representations $[70,^48]S_{ 11}$ and $[70,^28]S_{ 11}$, respectively; (iii) In the $K^-p\rightarrow \bar{ K}^0n$ process, the dominant resonances are $\Lambda(1405)$ and $\Lambda(1520)$. Some evidence of $\Lambda(1690)D_{ 03}$, $\Sigma(1670)D_{ 13}$ and $\Sigma(1775)D_{ 15}$ could be seen as well. A weak coupling of $\Lambda(1670)S_{ 01}$ to $\bar{ K}N$ should be needed in the reactions $K^-p\rightarrow \Sigma^0\pi^0$ and $\bar{ K}^0n$. Furthermore, by analyzing these reactions, we also find that the $u$-, t-channel backgrounds and s-channel Born term play crucial roles in the reactions.
Categories: nucl-th hep-ex hep-ph nucl-ex