Angle-dependent normalization of neutron-proton differential cross sections

Abstract

Systematic errors in the database of np differential cross sections below 350 MeV are studied. By applying angle-dependent normalizations with the help of the energy-dependent Nijmegen partial-wave analysis PWA93, the χ 2 -values of some seriously flawed data sets can be reduced significantly at the expense of a few degrees of freedom. It turns out that in these special cases the renormalized data sets can be made statistically acceptable such that they do not have to be discarded any longer in partial-wave analyses of the two-nucleon scattering data.

Measurement of the absolute differential cross section fornpelastic scattering at 194 MeV

“…The neutron-proton elastic scattering database at intermediate energies is plagued by experimental inconsistencies and cross section normalization difficulties [1,2,3]. These problems have led the most sophisticated partial wave analyses (PWA) of the data [4,5,6] to ignore the majority (including the most recent) of measured cross sections, while the literature is filled with heated debates over experimental and theoretical methods [7,8], including proposed radical "doctoring" (angledependent renormalization) to "salvage" allegedly flawed data [9]. Meanwhile, an empirical evaluation of a fundamental parameter of meson-exchange theories of the nuclear force -the charged πNN coupling constant, f 2 c -hangs in the balance [8].…”

Measurement of the AbsolutenpScattering Differential Cross Section at 194 MeV

“…Dn, 25.10.+s, 28.20.Cz The neutron-proton elastic scattering database at intermediate energies is plagued by experimental inconsistencies and cross section normalization difficulties [1,2,3]. These problems have led the most sophisticated partial wave analyses (PWA) of the data [4,5,6] to ignore the majority (including the most recent) of measured cross sections, while the literature is filled with heated debates over experimental and theoretical methods [7,8], including proposed radical "doctoring" (angledependent renormalization) to "salvage" allegedly flawed data [9]. Meanwhile, an empirical evaluation of a fundamental parameter of meson-exchange theories of the nuclear force -the charged πNN coupling constant, f 2 c -hangs in the balance [8].…”