Batelaan, M.Can, K.U.Horsley, R.Nakamura, Y.Rakow, P.E.L.Schierholz, G.Stüben, H.Young, R.D.Zanotti, J.M.2024-01-232024-01-232023Physical Review D (particles, fields, gravitation, and cosmology), 2023; 108(3):034507-1-034507-272470-00102470-0029https://hdl.handle.net/2440/140380The Feynman-Hellmann approach to computing matrix elements in lattice QCD by first adding a perturbing operator to the action is described using the transition matrix and the Dyson expansion formalism. This perturbs the energies in the two-point baryon correlation function, from which the matrix element can be obtained. In particular at leading order in the perturbation we need to diagonalize a matrix of near-degenerate energies. While the method is general for all hadrons, we apply it here to a study of a sigma to nucleon baryon transition vector matrix element.enPublished by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.Form factors; Baryons; Lattice gauge theoryJournal article10.1103/physrevd.108.0345072023-12-14644635Can, K.U. [0000-0002-7052-1421]Young, R.D. [0000-0002-4527-1811]Zanotti, J.M. [0000-0002-3936-1597]