Spin asymmetries in γ N→(K)over-bar*Θ+

The photoproduction processes of the exotic Theta(+)(1540) baryon and the (K) over bar* meson from the nucleon targets, i.e., gamman --> K*- Theta(+) and gammap --> (K) over bar*(0)Theta(+), are investigated in a hadronic model. We consider K and K* exchanges as well as the s and u channel nucleon and e terms. Various spin asymmetries together with cross sections are first computed in order to study the production mechanisms and the parity of the Theta(+)(1540) baryon. Within the uncertainties arising from the model-dependence of the production mechanisms and several coupling constants, we find that some target-recoil double spin asymmetries, C-xx(TR), and C-xz(TR), are sensitive to the parity of Theta(+). In addition, the parity asymmetry of this reaction on the neutron target, which can be obtained by analyzing K* decay distribution, is found to be useful to estimate the K*NTheta coupling. (C) 2004 Elsevier B.V. All rights reserved.