2004/11/28 by Yu. N. Uzikov, Uzikov, Yu. N.
Physics and Astronomy · #Atomic and Subatomic Physics Research #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Nuclear Theory (nucl-th) #Physics of Superconductivity and Magnetism #Quantum Chromodynamics and Particle Interactions #hep-ph #nucl-th
paper · pdf · doi:10.48550/arxiv.nucl-th/0411113
45 pages, Latex, no figures. New references added
openalex publication_date 2004/11/28 · arxiv created 2004/12/02 · arxiv updated 2009/12/01 · openalex created_date 2024/04/10 · openalex updated_date 2026/07/28
Spin observables of a binary reaction 1+2→ 3+4 are discussed at the threshold in general form using P-parity and angular momentum conservation. General formulae for polarization transfer, spin-spin correlation parameters in the initial and final states and induced tensor polarization are derived for arbitrary spins of participating particles. This formalism is worked out in detail for the NN→ YΘ+ reaction. Assuming that the spin of the pentaquark Θ+ takes the values 1/2, 3/2 and 5/2, whereas the spin of the hyperon Y equals 1/2, explicite formulae are obtained for the observables in terms of few non-vanishing at the threshold spin amplitudes separately for the spin-singlet and spin-triplet initial NN states. In case of all particles in the NN→ YΘ+ reaction have the spin-1/2 a full spin-structure for totally polarized cross sections is derived. Some of the obtained spin observables strongly depend on the intrinsic P-parity of the Θ+ and the total isospin of the reaction. Therefore, a measurement of these observables allows one to determine the P-parity of the pentaquark Θ+ in a model independent way for any spin of the Θ+.