Nucleon-nucleon phase shift analysis

Abstract

An energy dependent phase-shift analysis is reported for pp, np and pn elastic scattering between 10 and 800 MeV. For the pp case a unique solution smoothly varying with energy is found. A resonant behaviour is observed only in the 1D2 phase shift near the mass 2.14 GeV. For np and pn scattering only a few complex polarization parameters are available ; therefore the solution is less precise, especially above 500 MeV. A fixed-energy analysis at 1 GeV is also reported providing a unique phase-shift set. The formalism, data base and compatibility with other analyses are discussed

An energy dependent phase shift analysis of proton-proton scattering between 700 and 1300 MeV

“…A most important disagreement can be seen in figure 2 for the Re 3P2 phase shift from 400 MeV on. The present analysis confirms the behaviour observed in reference [1].…”

“…This analysis, as well as that of reference [1] [3] ; 0 Analysis of reference [8] (Fig. 14c) may be consistent with a possible resonance structure in one of the P waves, suggested by Lomon [65].…”

“…The present PSA uses the same amplitude formalism, one pion exchange (OPE) contributions, electromagnetic contributions and a phase shift energy dependence as described in reference [1].…”

Minimally nonlocal nucleon-nucleon potentials with chiral two-pion exchange includingΔresonances

“…The functions a, m, g, h, and c are taken to depend on the energy in the laboratory (lab) frame and the scattering angle θ in the center-of-mass (cm) frame. Any scattering observable can be constructed out of these amplitudes [30,31]. The N N amplitude is diagonal in pair spin S, and pair isospin and isospin projection T M T , and is expanded in partial waves as…”

“…On the experimental side, there are currently ∼ 8000 published pp and np scattering data below pion production threshold corresponding to 24 different scattering observables, including differential cross sections, spin asymmetries, and total cross sections [30,31], see Ref. [12] for updated pp and np abundance plots in the (E lab , θ cm ) plane.…”