A possibility to determine the P-parity of the ${\Theta }^{+}$ pentaquark in the $pn\to {\Lambda }^0{\Theta }^{+}$ reaction

Abstract

Spin structure of the reaction $\vec{p}\vec{n}\to {\vec{\Lambda }}^0\vec{\Theta }$ is analysed at the threshold in a model independent way under assumption that the ${\Theta }^{+}$ is an isosinglet. We found that the sign of the spin-spin correlation parameter $C_{x,x}$ being measured in a double-spin experiment, determines the P-parity of the ${\Theta }^{+}$ unambiguously. Furthermore we show that the polarization coefficients $K_x^x,K_y^y$ and $K_z^z$ which describe the polarization transfer from polarized beam or target to the final ${\Lambda }^0$ and ${\Theta }^{+}$ are nonzero for a positive parity of the ${\Theta }^{+}$ and equal zero for a negative parity. It allows one to determine the P-parity of the ${\Theta }^{+}$ in a single-spin measurement, since the polarization of the ${\Lambda }^0$ can be measured via its decay ${\Lambda }^0\to {\pi }^{-}+p$.

8 pages, Latex . The spin 3/2 of the ${\Theta }^{+}$ and a discrimination for the isospin T=0,1 and 2 are briefly discussed; minor corrections are performed

References in corpus (9)

• Diquarks and Exotic Spectroscopy
• Observation of an Exotic $S=+1$ Baryon in Exclusive Photoproduction from the Deuteron
• Observation of a baryon resonance with positive strangeness in K+ collisions with Xe nuclei
• Evidence for the positive-strangeness pentaquark ${\Theta }^{+}$ in photoproduction with the SAPHIR detector at ELSA
• Observation of an Exotic Baryon with S=+1 in Photoproduction from the Proton
• Interpretation of the Theta+ as an isotensor pentaquark with weakly decaying partners
• Pentaquark states in a chiral potential
• ${\Theta }^{+}$ in a chiral constituent quark model and its interpolating fields
• A Method to Unambiguously Determine the Parity of the Theta+ Pentaquark

Cited by in corpus (10)

• Pentaquark Theta^+(1540) production in gamma N --> K Anti-K N
• On the determination of the parity of the ${\Theta }^{+}$
• Phenomenology of spin 3/2 baryons with pentaquarks
• Polarization observables in the processes $p+p\to {\Theta }^{+}+{\Sigma }^{+}$ and $n+p\to {\Theta }^{+}+{\Lambda }^0$, for any spin and parity of the ${\Theta }^{+}$-hyperon in the threshold region
• Model-independent methods to measure the $P$-parity of the ${\Theta }^{+}$-pentaquark in photoproduction experiments
• $P$-parity of charm and strange particles in electroproduction processes, in collinear regime
• Spin correlations in the reaction "pi \vec D --> \vecΣΘ^+" and the parity of Theta^+
• Remarks on the parity determination of narrow resonances
• Angular distribution and azimuthal asymmetry for pentaquark production in proton-proton collisions
• Spin observables of the reactions NN -> DeltaN and pd -> Delta (pp)(1S0) in collinear kinematics