Speaker
Shuntaro Sakai
(I)
Description
In order to study the properties of the $N^∗(1535)$ and $N^∗(1650)$ we calculate the mass distributions of $MB$ in the $Λ_c\rightarrow \bar{K}^0MB$ decay, with $MB=\pi N(I= 1/2)$, $\eta p$ and $K\Sigma(I= 1/2)$. We do this by calculating the tree-level and loop contributions, mixing pseudoscalar-baryon and vector-baryon channels using the local hidden gauge formalism. The loop contributions for each channel are calculated using the chiral unitary approach. We observe that for the $\eta N$ mass distribution only the $N^∗(1535)$ is seen, with the $N^∗(1650)$ contributing to the width of the curve, but for the $\pi N$ mass distribution both resonances are clearly visible. In the case of $MB=K\Sigma$, we found that the strength of the $K\Sigma$ mass distribution is smaller than that of the mass distributions of the $\pi N$ and $\eta p$ in the $\Lambda_c\rightarrow \bar{K}^0\pi N$ and $\Lambda_c\rightarrow \bar{K}^0\eta p$ processes, in spite of this channel having a large coupling to the $N^∗(1650)$. This is because the $K\Sigma$ pair production is suppressed in the primary productionfrom the $\Lambda_c$ decay.
