Next-to-leading ultrasoft running of the heavy quarkonium potentials and spectrum: Spin-independent case

TL;DR

This paper calculates high-order ultrasoft corrections to heavy quarkonium potentials and spectrum, achieving NLL and N$^3$LL accuracy, which enhances theoretical precision for quarkonium energy levels.

Contribution

It provides the first computation of NLL ultrasoft running of spin-independent potentials up to 1/m^2 and the NNNLL static energy, advancing precision in heavy quarkonium spectroscopy.

Findings

Computed NLL ultrasoft running of spin-independent potentials.

Derived NNNLL order static energy for heavy quarkonium.

Calculated N$^4$LO ultrasoft contributions to quarkonium mass.

Abstract

We compute the next-to-leading logarithmic (NLL) ultrasoft running of the spin-independent singlet potentials up to ${\cal O}(1/m^2)$, and the corresponding contribution to the spectrum. This includes the static energy at next-to-next-to-next-to-leading logarithmic (NNNLL) order. As a byproduct of these results one could obtain the heavy quarkonium spectrum with N$^3$LL accuracy for $l\not=0$ (angular momentum) and $s=0$ (spin) states, setting the stage for the full analytic and numerical N$^3$LL analysis of such quantity. We also compute the next-to-next-to-next-to-next-to-leading order (N$^4$LO) ultrasoft spin-independent contribution to the heavy quarkonium mass and static energy.