On the determination of the parity of the Θ+

We critically examine the possibility of determining the parity of the Θ+(1540) from the reactions NN→Θ+Y (Y=Λ,Σ) recently discussed in the literature. Specifically, we study the energy dependence of those observables that were suggested to be the most promising ones to unravel the parity of the Θ+, namely, the spin correlation coefficient Axx, and the spin transfer coefficient Dxx. We show that the energy dependence of σ0(1+Axx), corresponding to the spin-triplet production cross section, guarantees unambiguous information on the parity of the Θ+. Here, σ0 denotes the unpolarized cross section. Also, the possibility to determine the parity of the Θ+ through the energy dependence of σ0Dxx is discussed.