6533b7cefe1ef96bd1256e44

RESEARCH PRODUCT

Role of theN*(1535)resonance and theπ−p→KYamplitudes in the OZI forbiddenπN→ϕNreaction

subject

description

We study the $\ensuremath{\pi}N\ensuremath{\rightarrow}\ensuremath{\phi}N$ reaction close to the $\ensuremath{\phi}N$ threshold within the chiral unitary approach, by combining the ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}{K}^{+}{\ensuremath{\Sigma}}^{\ensuremath{-}},{\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}{K}^{0}{\ensuremath{\Sigma}}^{0}$, and ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}{K}^{0}\ensuremath{\Lambda}$ amplitudes with the coupling of \ensuremath{\phi} to the $K$ components of the final states of these reactions via quantum loops. We obtain good agreement with experiment when the dominant ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}{K}^{0}\ensuremath{\Lambda}$ amplitude is constrained with its experimental cross section. We also evaluate the coupling of ${N}^{*}(1535)$ to $\ensuremath{\phi}N$ and find a moderate coupling as a consequence of partial cancellation of the large $\mathit{KY}$ components of ${N}^{*}(1535)$. We also show that the ${N}^{*}(1535)$ pole approximation is too small to reproduce the measured cross section for the ${\ensuremath{\pi}}^{\ensuremath{-}}N\ensuremath{\rightarrow}\ensuremath{\phi}N$ reaction.