Year: 2019
Type: article
Abstract: In this paper, we implement the use of a $\ensuremath{\pi}N\mathrm{\ensuremath{\Delta}}$(1232) vertex interaction containing both first- and second-order derivative terms, as required by renormalization and power-counting considerations. As was previously shown, both interactions present quantization shortcomings but can be used in a pertubative calculation. Our results indicate that the usual $\ensuremath{\pi}$ derivative plus the spin-3/2 gauge invariant (derivative also in the $\mathrm{\ensuremath{\Delta}}$ field) should be included in amplitude calculations, as also all higher derivative interactions respecting chiral invariance. We show that both interactions make essentially the same resonant contribution to the elastic ${\ensuremath{\pi}}^{+}p$ cross section, so changing the ratio between both coupling constants amounts to a correction of the background. The elastic ${\ensuremath{\pi}}^{+}p$ cross section up to 300 MeV changes only mildly when that ratio is changed, but the total ${\ensuremath{\pi}}^{\ensuremath{-}}p$ scattering, which has poor fit within both interactions separately, can be much improved in the same energy range by tuning the ratio between both coupling constants.
Source: Physical Review C
Language: Latvian
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W2767777261