Proton polarisability contribution to the Lamb shift in muonic hydrogen at fourth order in chiral perturbation theory

Abstract

We calculate the amplitude T_1 for forward doubly-virtual Compton scattering in heavy-baryon chiral perturbation theory, to fourth order in the chiral expansion and with the leading contribution of the gammaNDelta form factor. This provides a model-independent expression for the amplitude in the low-momentum region, which is the dominant one for its contribution to the Lamb shift. It allows us to significantly reduce the theoretical uncertainty in the proton polarisability contributions to the Lamb shift in muonic hydrogen. We also stress the importance of consistency between the definitions of the Born and structure parts of the amplitude. Our result leaves no room for any effect large enough to explain the discrepancy between proton charge radii as determined from muonic and normal hydrogen.

9 pages, 2 figures; added discussion of matching ChPT form factor onto dipole form at non-zero Q^2; no significant changes in results

References in corpus (8)

• High-precision determination of the electric and magnetic form factors of the proton
• Electromagnetic excitation of the Delta(1232)-resonance
• Chiral Perturbation Theory and Baryon Properties
• Global analysis of proton elastic form factor data with two-photon exchange corrections
• Using effective field theory to analyse low-energy Compton scattering data from protons and light nuclei
• Chiral Effective-Field Theory in the Delta(1232) Region: Pion Electroproduction on the Nucleon
• The Electromagnetic Self-Energy Contribution to M_p - M_n and the Isovector Nucleon Magnetic Polarizability
• Forward virtual Compton scattering and the Lamb shift in chiral perturbation theory

Cited by in corpus (34)

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• The Proton Radius Puzzle
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• Compton scattering from the proton in an effective field theory with explicit Delta degrees of freedom
• The NRQED lagrangian at order 1/M^4
• The two-photon exchange contribution to muonic hydrogen from chiral perturbation theory
• The proton structure in and out of muonic hydrogen
• Comprehensive theory of the Lamb shift in light muonic atoms
• New Measurement of Compton Scattering from the Deuteron and an Improved Extraction of the Neutron Electromagnetic Polarizabilities
• Expanding Nuclear Physics Horizons with the Gamma Factory
• Improved estimates of the nuclear structure corrections in $\mu$D
• Proton radius from electron-proton scattering and chiral perturbation theory
• Two-photon exchange contribution to elastic $e^{-}$-proton scattering: Full dispersive treatment of $\pi N$ states and comparison with data
• The proton radius (puzzle?) and its relatives
• Nucleon Compton scattering in the Dyson-Schwinger approach
• Two-photon exchange correction to the hyperfine splitting in muonic hydrogen
• Two-photon exchange correction to $2S$-$2P$ splitting in muonic helium-3 ions
• Dispersive estimate of the electromagnetic charge symmetry violation in the octet baryon masses
• Forward sum rule for the $2\gamma$-exchange correction to the charge radius extraction from elastic electron scattering
• The recoil correction to the proton-finite-size contribution to the Lamb shift in muonic hydrogen
• Model independent determination of the muonic hydrogen Lamb shift and proton radius
• Lattice QCD calculation of the two-photon exchange contribution to the muonic-hydrogen Lamb shift
• Two-photon-exchange effects in the unpolarized $\mu p$ scattering within the hadronic model
• A self-consistent value of the electric radius of the proton from the Lamb shift in muonic hydrogen
• Forward doubly-virtual Compton scattering off the nucleon in chiral perturbation theory: the subtraction function and moments of unpolarized structure functions
• Precision calculation of the recoil--finite-size correction for the hyperfine splitting in muonic and electronic hydrogen
• Proton Compton Scattering from Linearly Polarized Gamma Rays
• Two-photon exchange in (muonic) deuterium at N3LO in pionless effective field theory
• Forward doubly-virtual Compton scattering off an unpolarised deuteron in pionless effective field theory
• Virtual Compton scattering at low energies with a positron beam
• Disperon QED
• Soft-photon radiative corrections to the $e^{-}p\to e^{-}p{l}^{-}{l}^{+}$ process