dorsal/arxiv
View SchemaHow low-energy weak reactions can constrain three-nucleon forces and the neutron-neutron scattering length
| Authors | A. Gardestig, D. R. Phillips |
|---|---|
| Categories | |
| ArXiv ID | nucl-th/0603045 |
| URL | https://arxiv.org/abs/nucl-th/0603045 |
| DOI | 10.1103/PhysRevLett.96.232301 |
| Journal | Phys.Rev.Lett.96:232301,2006 |
Abstract
We show that chiral symmetry and gauge invariance enforce relations between the short-distance physics that occurs in a number of electroweak and pionic reactions on light nuclei. Within chiral perturbation theory this is manifested via the appearance of the same axial isovector two-body contact term in pi- d -> n n gamma, p-wave pion production in NN collisions, tritium beta decay, pp fusion, nu d scattering, and the hep reaction. Using a Gamow-Teller matrix element obtained from calculations of pp fusion as input we compute the neutron spectrum obtained in pi- d -> n n gamma. With the short-distance physics in this process controlled from p p -> d e+ nu_e the theoretical uncertainty in the nn scattering length extracted from pi- d -> n n gamma is reduced by a factor larger than three, to <~0.05 fm.
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"abstract": "We show that chiral symmetry and gauge invariance enforce relations between\nthe short-distance physics that occurs in a number of electroweak and pionic\nreactions on light nuclei. Within chiral perturbation theory this is manifested\nvia the appearance of the same axial isovector two-body contact term in pi- d\n-\u003e n n gamma, p-wave pion production in NN collisions, tritium beta decay, pp\nfusion, nu d scattering, and the hep reaction. Using a Gamow-Teller matrix\nelement obtained from calculations of pp fusion as input we compute the neutron\nspectrum obtained in pi- d -\u003e n n gamma. With the short-distance physics in\nthis process controlled from p p -\u003e d e+ nu_e the theoretical uncertainty in\nthe nn scattering length extracted from pi- d -\u003e n n gamma is reduced by a\nfactor larger than three, to \u003c~0.05 fm.",
"arxiv_id": "nucl-th/0603045",
"authors": [
"A. Gardestig",
"D. R. Phillips"
],
"categories": [
"nucl-th"
],
"doi": "10.1103/PhysRevLett.96.232301",
"journal_ref": "Phys.Rev.Lett.96:232301,2006",
"title": "How low-energy weak reactions can constrain three-nucleon forces and the neutron-neutron scattering length",
"url": "https://arxiv.org/abs/nucl-th/0603045"
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