Spin asymmetries in γN → K̄ ∗ Θ +

Abstract The photoproduction processes of the exotic Θ+(1540) baryon and the K∗ meson from the nucleon targets, i.e., γn → K∗−Θ+ and γp → K̄∗0Θ+, are investigated in a hadronic model. We consider K and K∗ exchanges as well as the s and u channel terms. Various spin asymmetries together with cross sections are estimated in order to study the production mechanisms and the parity of the Θ+(1540) baryon. We found that some spin asymmetries including target-recoil double spin asymmetries CTR xx and C TR xz are sensitive to the parity of the Θ +. However, because of the dependence of the spin asymmetries on the production mechanisms and the difficulties of measuring the polarization of the produced Θ+, it is desirable to measure various spin asymmetries with polarized beam and/or polarized proton and neutron targets to get a definite conclusion on the parity of the Θ+. We also find that the parity asymmetry of this reaction on the neutron target is very useful to study the contributions from the K∗NΘ interaction.