The photoproduction processes of the exotic Θ+ (1540) baryon and the K̄* 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 nucleon and Θ terms. Various spin asymmetries together with cross sections are first computed in order to study the production mechanisms and the parity of the Θ+ (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, Cxx′TR and Cxz′TR, are sensitive to the parity of Θ+. 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* N Θ coupling.
Bibliographical noteFunding Information:
We are grateful to V. Burkert, H. Gao, A. Hosaka, V. Kubarovsky, T.-S.H. Lee, T. Nakano, B.-Y. Park and E. Smith for fruitful discussions and valuable informations. Y.O. is grateful to the Thomas Jefferson National Accelerator Facility for its warm hospitality. This work was supported by the Brain Korea 21 project of Korean Ministry of Education and by KOSEF under Grant No. 1999-2-111-005-5. The work of Y.O. was supported in part by DOE contract DE-AC05-84ER40150 under which the Southeastern Universities Research Association (SURA) operates the Thomas Jefferson National Accelerator Facility.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics