2011/05/18 by Johannes Kirscher, Kirscher, Johannes · 2 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #FOS: Physical sciences #Nuclear Experiment (nucl-ex) #Nuclear Theory (nucl-th) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #nucl-ex #nucl-th
paper · pdf · doi:10.48550/arxiv.1105.3763
6 pages, 3 figures, 1 table, submitted to Phys. Lett. B
arxiv created 2011/05/18 · openalex publication_date 2011/05/18 · arxiv updated 2011/05/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Model-independent constraints for the neutron-triton and proton-Helium-3 scattering lengths are calculated with a leading-order interaction derived from an effective field theory without explicit pions. Using the singlet neutron-proton scattering length, the deuteron, and the triton binding energy as input, the predictions \ants=9.2±2.6 fm, \antt=7.6±1.6 fm, \aphes=3.6±0.32 fm, and \aphet=3.1± 0.23 fm are obtained. The calculations employ the resonating group method and include the Coulomb interaction when appropriate. The theoretical uncertainty is assessed via a variation of the regulator parameter of the short-distance interaction from 400 MeV to 1.6 GeV. The phase-shift and scattering-length results for the proton-Helium-3 system are consistent with a recent phase shift analysis and with model calculations. For neutron-triton, the results for the scattering lengths in both singlet and triplet channels are significantly smaller than suggested by R-matrix and partial-wave-analysis extractions from data. For a better understanding of this discrepancy, the sensitivity of the low-energy four-body scattering system to variations in the neutron-neutron and proton-proton two-nucleon scattering lengths is calculated. Induced by strong charge-symmetry-breaking contact interactions, this dependence is found insignificant. In contrast, a strong correlation between the neutron-triton scattering length and the triton binding energy analogous to the Phillips line is found.