Possible methods for the determination of the $P$-parity of the ${\Theta }^{+}$-pentaquark in NN-collisions

Abstract

We present two possibilities to determine the P-parity of the pentaquark ${\Theta }^{+}$, in a model independent way, via the measurement of polarization observables in $p+p\to {\Theta }^{+}+{\Sigma }^{+}$, or $n+p\to {\Theta }^{+}+{\Lambda }^0$, in the near threshold region. Besides the measurement of the spin correlation coefficient, $A_{xx}=A_{yy}$, (in collisions of transversally polarized nucleons), the coefficient $D_{xx}$ of polarization transfer from the initial proton to the final ${\Sigma }^{+}({\Lambda }^0)$ hyperon is also unambiguously related to the ${\Theta }^{+}$ parity.

7 pages, 1 figure