Reparameterization invariance of NRQED self-energy corrections and improved theory for excited D states in hydrogenlike systems

TL;DR

This paper demonstrates the reparameterization invariance of NRQED self-energy corrections across different regularization schemes and introduces new techniques for calculating low-energy contributions, improving predictions for excited hydrogenlike states.

Contribution

It establishes the invariance of NRQED self-energy calculations under various regularization parameters and develops advanced methods for precise low-energy correction computations.

Findings

Reparameterization invariance confirmed across multiple regularization schemes.

New techniques improve calculation accuracy for low-energy self-energy corrections.

Enhanced predictions for Lamb shifts in highly excited states.

Abstract

Canonically, the quantum electrodynamic radiative corrections in bound systems have been evaluated in photon energy regularization, i. e. using a noncovariant overlapping parameter that separates the high-energy relativistic scales of the virtual quanta from the nonrelativistic domain. Here, we calculate the higher-order corrections to the one-photon self-energy calculation with three different overlapping parameters (photon energy, photon mass and dimensional regularization) and demonstrate the reparameterization invariance of nonrelativistic quantum electrodynamics (NRQED) using this particular example. We also present new techniques for the calculation of the low-energy part of this correction, which lead to results for the Lamb shift of highly excited states that are important for high-precision spectroscopy.