Proton-Proton Scattering: Revision and Analysis of Experimental Measurements from 1.4 to 3.0 MeV

Abstract

Revised experimental values are given for the differential cross section for proton-proton scattering at energies of 1.397, 1.855, 2.425, and 3.037 MeV. These result from the consolidation and re-evaluation of all published and unpublished data obtained in an experiment reported earlier by Knecht et at. Phase-shift analyses have been made. The preferred solutions determine the 5-wave phase shift KQ and the central-force ("effective") part y of the P-wave phase shifts, under the assumption that the noncentralforce parts and all higher angular-momentum phase shifts are known with sufficient accuracy from one-pionexchange theory; the values of y derived in this way are small, with zero not excluded. Other solutions in which noncentral forces range from zero to very large values are given for comparison. The uncertainty in each of the derived phase shifts is calculated and discussed in detail; uncertainties obtained by the usual statistical method are shown to be too small. The polarization implied by each phase-shift solution has been calculated, and it is shown that reported measurements are in disagreement not only with the present data and theoretical predictions but with any combination of central, tensor, and spin-orbit forces.

Phase shift analysis of 0–30 MeV pp scattering data

“…χ 2 /N df = 1 ± 2/N df ) are not valid anymore. The Wisconsin66 1-3 MeV cross section data [69] form an example of the above situation. Before the publication of the Zürich78 data [3], the Wisconsin66 data were the only cross sections below 5 MeV and away from the interference minimum that were incorporated in analyses.…”

“…At these very low energies only differential cross section data are available. Earlier analyses had only available the 5 Los Alamos64 data [70] around the interference minimum, measured by Brolley et al, and the 51 Wisconsin66 1-3 MeV data [69] of Knecht et al The 9 Basel73 data [4,5] below 2 MeV have not been included in the earlier analyses. It has been known for a long time that the Wisconsin66 data have errors with a large systematic component (see also van der Sanden et al [17] or SSH [12].)…”

Proposal to Confirm the Strong van der Waals Interaction in Low Energy p-p Scattering

“…The unitarity cut at v>O is removed by considering a function Ka (v) / v; _KaSv)= ha(li_~_1__ r= Im _! :a_Cv')dv'=-~g_S!_) -Ia(v), (12) v v…”

“…(v) in Eq (12),. and we shall use the energy dependent phase shift data byMcGregor, Arndt and Wright (MAW) 8 ).…”

S-Wave Shape-Dependent Scattering Parameters of the Proton-Proton Interaction

“…The relation of (1) with the 1 S 0 p-p phase shifts and more currently used scattering parameters is obtained through the equation K-RF 9 where F = C 2 fccot6 + (1/R)h(r}) = -l/« +fr k 2 -Pr 3 fe 4 +Qr 5 k 6 ,…”