Signature of the $\Lambda (1405)$ resonance in neutron spectra from the $K^{-}+d$ reaction

Abstract

Neutron spectra from the reaction $K^{-}+d\to \pi +\Sigma +n$ were calculated in the energy range $E_{K^{-}}^{cm}=0-50MeV$ using coupled channel Faddeev equations for the description of the $\bar{K}NN-\pi \Sigma N$ three-body system. The aim was to trace the signature of the $\Lambda (1405)$ resonance in the spectra. We found, that while in the direct spectra kinematic effects mask completely the peak corresponding to the resonance, the deviation spectrum method [1] is able to eliminate kinematics and differentiate between different models of $\Lambda (1405)$. Four different phenomenological $\bar{K}N-\pi \Sigma$ interactions were used in order to study the effect of their pole positions on the neutron spectra.

Comments: Final version to appear in Few Body Systems