Electromagnetic production of mesons and hyperons from nuclei
A relativistic plane wave model is developed for electromagnetic production of unbound hyperons with free kaons from nuclei. The differential cross section is expressed as a contraction of leptonic and hadronic tensors. The leptonic tensor is constructed by using the helicity representation of a free Dirac spinor. A model for the corresponding elementary process is used to calculate the hadronic tensor, in which the hadronic current operator Jˆμ is written as a linear combination of six invariant amplitudes and six Lorentz and gauge invariant quantities. The kinematics for this process is assumed to be a quasi-free process i.e., the electron interacts with only one bound nucleon inside the nucleus. The bound state wavefunction of the bound nucleon is calculated within the framework of the relativistic mean-field approximation. The unpolarized differential cross section for the K+ electroproduction process, e + A −→ e + K+ + A + Aresidual is calculated as a function of the hyperon scattering angle.