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Understanding the proton radius puzzle: Nuclear structure effects in light muonic atoms


  Nir Nevo Dinur [1]  ,  Chen Ji [2]  ,  Oscar J. Hernandez [3,4]  ,  Sonia Bacca [3,4]  ,  Nir Barnea [1]  
 [1] The Hebrew University of Jerusalem, Israel
[2] ECT*, Trento, Italy
[3] TRIUMF, Vancouver, BC, Canada
[4] University of Manitoba, Winnipeg, MB, Canada

 The most precise determination of the proton charge radius, from a novel muonic hydrogen (µ-1H) spectroscopy experiment [1], disagrees with previous spectroscopy and scattering experiments done with electrons. This 7σ discrepancy, known as the “proton radius puzzle”, may be the result of new physics [2]. In order to investigate this, experiments with other muonic atoms have been conducted [3]. These experiments and their analyses must rely on accurate theoretical predictions. In particular, their precision is ultimately limited by the nuclear structure effects. We have calculated these effects for several muonic atoms with A=2,3,4 nucleons, using state-of-the-art nuclear potentials, significantly improving previous estimates [4,5,6]. Our results will be presented and discussed, focusing on recent developements.

 

References

  1. R. Pohl, et al., Nature (London) 466, 213 (2010); A. Antognini et al., Science 339, 417 (2013).

  2. R. Pohl, R. Gilman, G. A. Miller, and K. Pachucki, Ann. Rev. of Nucl. and Part. Sci. 63, 175 (2013).

  3. A. Antognini et al., Can. J. Phys. 89, 47 (2011); R. Pohl, Hyperfine Interact. 227, 23 (2014).

  4. C. Ji, NND, S. Bacca, and N. Barnea, Phys. Rev. Lett. 111, 143402 (2013).

  5. O. J. Hernandez, C. Ji, S. Bacca, NND, and N. Barnea, Phys. Lett. B 736, 344 (2014).

  6. NND, C. Ji, S. Bacca, and N. Barnea, in preparation.