A bound on the nucleon Druck-term from chiral EFT in curved space-time and mechanical stability conditions

• Published in: Physics letters. B Vol. 820; p. 136572
• Main Authors: Gegelia, Jambul, Polyakov, Maxim V.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 10.09.2021; Elsevier
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2021.136572

Using dispersive representations of the nucleon gravitational form factors, the results for their absorptive parts from chiral effective field theory in curved space-time, and the mechanical stability conditions, we obtain a model independent inequality for the value of the gravitational D(t) form factor at zero momentum transfer (Druck-term). In particular, the obtained inequality leads to a conservative bound on the Druck-term in the chiral limit D≤−0.95(9). This bound implies the restriction on the low-energy constant c8 of the effective chiral action for nucleons and pions in the presence of an external gravitational field, c8≤−1.1(1) GeV−1. For the physical pion mass we obtain a model independent bound D≤−0.20(2).