Physical Review D
We present a model-independent framework to determine finite-volume corrections of matrix elements of spatially separated current-current operators. We define these matrix elements in terms of Compton-like amplitudes, i.e., amplitudes coupling single-particle states via two current insertions. We show that the infrared behavior of these matrix elements is dominated by the single-particle pole, which is approximated by the elastic form factors of the lowest-lying hadron. Therefore, given lattice data on the relevant elastic form factors, the finite-volume effects can be estimated nonperturbatively and without recourse to effective field theories. For illustration purposes, we investigate the implications of the proposed formalism for a class of scalar theories in two and four dimensions.
Original Publication Citation
Briceño, R. A., & Monahan, C. J. (2021). Model-independent framework for determining finite-volume effects of spatially nonlocal operators. Physical Review D, 103(9), 1-12, Article 094521. https://doi.org/10.1103/PhysRevD.103.094521
Briceño, Raúl A. and Monahan, Christopher J., "Consistency Checks For Two-Body Finite-Volume Matrix Elements: Conserved Currents and Bound States" (2021). Physics Faculty Publications. 531.