High-momentum physics in low-momentum effective theories

Scott Bogner

Michigan State University

Ab-initio calculations of nuclear structure have seen explosive progress, thanks in part to simplifications that result from renormalization group (RG) evolution to “low RG resolution”. The RG resolution can be thought of as the effective UV momentum cutoff in the nuclear Hamiltonian and low-energy wave functions. Low RG resolutions are advantageous since wave functions are less correlated and become amenable to simple perturbative treatments, allowing calculations to be pushed well into the medium-mass region. Workhorses of nuclear structure such as the nuclear shell model and energy density functional methods are examples of low resolution pictures.  Conversely, there has been impressive progress in probing the short distance/high-momentum structure of nuclei using hard electron scattering, where a high resolution picture might appear to be more natural. An important question to ask is, how do we reconcile the low resolution pictures that dominate low-energy nuclear structure, with the high-resolution pictures utilized in the studies of short-range correlation (SRC) physics probed in hard electron scattering.

In this talk, Dr. Bogner will show how high-momentum operators (and physical interpretations!) evolve as the resolution is varied using the renormalization group. Interestingly, we find that some aspects of high-momentum/SRC physics are easier to calculate in low resolution pictures.