: Higher derivative terms in the pi Delta N interaction: some phenomenological consequences

A. MARIANO; D. BADAGNANI; C. BARBERO; E. BERRUETA MARTÍNEZ

PHYS. REV. - C

AMER PHYSICAL SOC

Año: 2019 vol. 100 p. 24001 - 24007

0556-2813

In this paper, we implement the use of a πN(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 π derivative plus the spin-3/2 gauge invariant (derivative also in the 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 π+p cross section, so changing the ratio between both coupling constants amounts to a correction of the background. The elastic π+pcross section up to 300 MeV changes only mildly when that ratio is changed, but the total π−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.