dorsal/arxiv
View SchemaParity and spin of the $\Theta^+$ pentaquark in the $NN\to Y\Theta^+$ reaction at the threshold
| Authors | Yu. N. Uzikov |
|---|---|
| Categories | |
| ArXiv ID | nucl-th/0411113 |
| URL | https://arxiv.org/abs/nucl-th/0411113 |
Abstract
Spin observables of a binary reaction $1+2\to 3+4$ 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 $NN\to Y\Theta^+$ reaction. Assuming that the spin of the pentaquark $\Theta^+$ 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 $NN\to Y\Theta^+$ 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 $\Theta^+$ and the total isospin of the reaction. Therefore, a measurement of these observables allows one to determine the P-parity of the pentaquark $\Theta^+$ in a model independent way for any spin of the $\Theta^+$.
{
"annotation_id": "a13b5119-ebf3-4d6c-8011-6e14df4aaab2",
"date_created": "2026-03-02T18:00:04.739000Z",
"date_modified": "2026-03-02T18:00:04.739000Z",
"file_hash": "caef14332ef73c2e676356652a81f2c431cf2895f63c449ef668c1bbf04aea18",
"private": false,
"record": {
"abstract": "Spin observables of a binary reaction $1+2\\to 3+4$ are discussed at the\nthreshold in general form using P-parity and angular momentum conservation.\nGeneral formulae for polarization transfer, spin-spin correlation parameters in\nthe initial and final states and induced tensor polarization are derived for\narbitrary spins of participating particles. This formalism is worked out in\ndetail for the $NN\\to Y\\Theta^+$ reaction. Assuming that the spin of the\npentaquark $\\Theta^+$ takes the values 1/2, 3/2 and 5/2, whereas the spin of\nthe hyperon $Y$ equals 1/2, explicite formulae are obtained for the observables\nin terms of few non-vanishing at the threshold spin amplitudes separately for\nthe spin-singlet and spin-triplet initial NN states. In case of all particles\nin the $NN\\to Y\\Theta^+$ reaction have the spin-1/2 a full spin-structure for\ntotally polarized cross sections is derived. Some of the obtained spin\nobservables strongly depend on the intrinsic P-parity of the $\\Theta^+$ and the\ntotal isospin of the reaction. Therefore, a measurement of these observables\nallows one to determine the P-parity of the pentaquark $\\Theta^+$ in a model\nindependent way for any spin of the $\\Theta^+$.",
"arxiv_id": "nucl-th/0411113",
"authors": [
"Yu. N. Uzikov"
],
"categories": [
"nucl-th",
"hep-ph"
],
"title": "Parity and spin of the $\\Theta^+$ pentaquark in the $NN\\to Y\\Theta^+$ reaction at the threshold",
"url": "https://arxiv.org/abs/nucl-th/0411113"
},
"schema_id": "dorsal/arxiv",
"source": {
"execution_id": "c72f43f1-4fcd-4354-8f37-ee22989b6d1a",
"id": "arXiv Dataset IDs",
"type": "Model",
"variant": "snapshot-2026-03-01",
"version": "0.1.0"
},
"user_id": 1000002
}