What new information about the microscopic quark structure of meson-baryon degrees of freedom in nucleons can be deduced from data on quasielastic pion knockout?

Abstract

The emergence of B + π virtual subsystems, which manifest themselves in quasielastic-knockout processes of the N(e, e′π)B type, where B is the final-state baryon in various excited states, is considered within the microscopic quark model of a 3P0 localized scalar fluctuation of the QCD vacuum. The relevant technique for taking into account the rearrangement of quark degrees of freedom is demonstrated. The model provides a good description of known momentum distributions for B=N channels. The momentum distributions are predicted for N → π + B channels, where B=Δ, N*(1535), or N**(1440). It would be of interest to study these channels in exclusive coincidence experiments at accelerators producing electron beams of energy ranging between 5 and 10 GeV.