Finite Volume Effects on the Extraction of Form Factors at Zero Momentum

Understand

Hadronic matrix elements that depend on momentum are required for numerous phenomenological applications.

• Probing the low-momentum regime is often problematic for lattice QCD computations on account of the restriction to periodic momentum modes.
• Recently a novel method has been proposed to compute matrix elements at zero momentum, for which straightforward evaluation of the matrix elements would otherwise yield a vanishing result.
• We clarify an assumption underlying this method, and thereby establish the theoretical framework required to address the associated finite volume effects.