Characteristic momentum scale of the OPE expansion

Determine the characteristic nuclear momentum scale \(Q_A\) that governs the large-momentum expansion of nucleon and two-nucleon momentum distributions in powers of \(Q_A/k\).

Background

The OPE framework assumes that the nucleon momentum distributions $\rho(k)$ and $\rho^{2N}(k)$ admit expansions in the ratio $Q_A/k$ at large momentum, where $Q_A$ represents the typical nucleon momentum in nucleus $A$. The value of this scale controls the expected convergence range of the expansion.

The paper discusses two possible estimates: the Fermi momentum from a mean-field perspective and the average binding momentum $\sqrt{2m_N B/A}$ commonly used in effective field theory. A definitive determination of $Q_A$ is not provided.