The electromagnetic radii of the proton, neutron and deuteron from spectroscopy of muonic hydrogen and deuterium with the help of chiral EFTs

ORAL

Abstract

The proton "charge radius puzzle" is known to affect the deuteron, so it is really a Z=1 puzzle. I will present the results of our recent calculations of the nuclear polarizability effect in muonic hydrogen (muH) and deuterium (muD) [1-4], and discuss their impact on the extraction of the charge radii of proton, neutron and deuteron. Our latest chiral EFT calculation of the polarizability effect in the hyperfine splitting (hfs) of muonic hydrogen is in condradiction with previous data-driven evaluations based on empirical spin structure functions g1 and g2 of the proton. This has an improtant implication for the first planned measurements of the ground-state hfs transition in muH by the FAMU and CREMA Collaborations.

I will highlight the prospects for improving the data-driven evaluations using the new data from the Jefferson Lab g2p experiment.



*This work is supported by the Deutsche Forschungsgemeinschaft (DFG) within the Research Unit FOR 5327.

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Publication: [1] A. Antognini, F. Hagelstein, V. Pascalutsa, "The proton structure in and out of muonic hydrogen," Ann.Rev.Nucl.Part.Sci. 72 (2022) 389.
[2] V. Lensky, F. Hagelstein, V. Pascalutsa, "A reassessment of nuclear effects in muonic deuterium using pionless effective field theory at N3LO," Phys.Lett.B 835 (2022) 137500.
[3] V. Lensky, F. Hagelstein, V. Pascalutsa, "Two-photon exchange in (muonic) deuterium at N3LO in pionless effective field theory," Eur.Phys.J.A 58 (2022) 11, 224.
[4] F. Hagelstein, V. Lensky, V. Pascalutsa, "Chiral perturbation theory of the hyperfine splitting in (muonic) hydrogen," e-Print: 2305.09633 [nucl-th].

Presenters

  • Vladimir Pascalutsa

    • Johannes Gutenberg University

Authors

  • Vladimir Pascalutsa

    • Johannes Gutenberg University

  • Franziska Hagelstein

    • Johannes Gutenberg University Mainz

  • Aldo Antognini

    • Paul Scherrer Institute

  • Vadim Lensky

    • Johannes Gutenberg University Mainz