Instanton-induced polarization in exclusive hyperon photoproduction

It is shown that instantons can provide an explanation of the strong polarization transfer observed in exclusive hyperon photoproduction at JLab.

Figure 1

The instanton mechanism for polarization transfer to a $\Lambda$ hyperon: (a) four-quark and (b) six-quark instanton-induced interaction contributions. Here I denotes the instanton, R and L are the quark helicities, and the detached arrows show the directions of the quark spins.