Proton Radius from Muonic Hydrogen Spectroscopy and Effect of Atomic Nucleus Motion

TL;DR

This paper proposes that the motion of the atomic nucleus in muonic hydrogen could explain the 4% discrepancy in proton radius measurements, potentially resolving the proton radius puzzle.

Contribution

It introduces a new hypothesis that nuclear motion effects may account for the proton radius discrepancy in muonic hydrogen spectroscopy.

Findings

Estimated effect of nucleus motion is significant enough to impact measurements.

Nuclear motion could be a key factor in resolving the proton radius puzzle.

The effect aligns with hyperfine structure observations.

Abstract

The proton radius has been measured in electron-proton scattering experiments and laser based spectroscopy of muonic hydrogen. The latter method is based on the precise calculations for the atomic energy levels in the approximation of static nucleus, and includes numerous corrective effects.The 4% discrepancy between two measuring methods is known as the proton radius puzzle. We suggest that this discrepancy may be caused by an additional electromagnetic interaction with the magnetic moment generated by then ucleus motion around the center of mass of the muonic hydrogen. The scale of this effect is estimated based on the known hyper fine structure of the muonic hydrogen. Our estimation show that the effect of the atomic nucleus motion is high enough and may help to solve the proton radius puzzle