%0 Journal Article
%T Light-quark mass dependence of the nucleon axial charge and pion-nucleon scattering phenomenology
%A Alvarado, F.
%A Alvarez-Ruso, L.
%J Physical Review D
%D 2022
%V 105
%N 7
%I Amer Physical Soc
%@ 2470-0010
%G English
%F Alvarado+Alvarez-Ruso2022
%O WOS:000791214200001
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5217), last updated on Mon, 16 May 2022 07:43:44 +0000
%X The light-quark mass dependence of the nucleon axial isovector charge (gA) has been studied up to nextto-next-to-leading order, O(p4), in relativistic chiral perturbation theory using extended-on-mass-shell renormalization, without and with explicit Delta(1232) degrees of freedom. We show that in the Delta-less case, at this order, the flat trend of gA(MN) exhibited by state-of-the-art lattice QCD (LQCD) results cannot be reproduced using low energy constants extracted from pion-nucleon elastic and inelastic scattering. A satisfactory description of these LQCD data is only achieved in the theory with Delta. From this fit, we report gA(MN(phys)) = 1.260 1 0.012, close to the experimental result, and d16 = -0.88 1 0.88 GeV-2, in agreement with its empirical value. The large uncertainties are of theoretical origin, reflecting the difference between O(p3) and O(p4) that still persists at large MN in presence of the Delta.
%R 10.1103/PhysRevD.105.074001
%U https://arxiv.org/abs/2112.14076
%U https://doi.org/10.1103/PhysRevD.105.074001
%P 074001-13pp