Opposite parity fermion mixing and baryons $1/2^{\pm }$

A. E. Kaloshin, E. A. Kobeleva, V. P. Lomov

We develop a variant of $K$-matrix, which includes the effect of opposite parity fermions (OPF) mixing, and apply it for description of $\pi N$ partial waves $S_{11}$ and $P_{11}$. OP…