22-26 January 2018
Bormio, Italy
Europe/Berlin timezone

Status of the proton radius puzzle

25 Jan 2018, 12:00
30m
Bormio, Italy

Bormio, Italy

Overview Talk Fundamental Interactions Thursday Morning

Speaker

Prof. Randolf Pohl (Johannes Gutenberg University Mainz)

Description

Laser spectroscopy of muonic hydrogen [1,2] yielded a proton rms charge radius which is 4% (or ~6 sigmas) smaller than the CODATA value [3]. Also the deuteron charge radius from muonic deuterium [4] is 6 sigmas smaller than the CODATA value, but consistent with the smaller proton inside the deuteron. These smaller charge radii, when combined with precision measurements of the 1S-2S transitions in regular (electronic) hydrogen [5] and deuterium [6], yield a 6 sigmas smaller value of the Rydberg constant [7], compared to the CODATA value. In this talk I will report about a new measurement of the Rydberg constant from the 2S-4P transition in regular hydrogen performed in Garching [8], which supports the smaller, "muonic" value. I will also discuss the measurements in muonic hydrogen, deuterium, and helium, and the consequences for the "proton radius puzzle". [1] Pohl et al. (CREMA Coll.), Nature 466, 213 (2010) [2] Antognini et al. (CREMA Coll.), Science 339, 417 (2013) [3] Mohr et al. (CODATA 2014), Rev. Mod. Phys. 88, 035009 (2016) [4] Pohl et al. (CREMA Coll.), Science 353, 669 (2016) [5] Parthey et al., PRL 107, 203001 (2011) [6] Parthey et al., PRL 104, 233001 (2010) [7] Pohl et al., Metrologia 54, L1 (2017) [8] Beyer et al., Science 358, 79 (2017)

Summary

Laser spectroscopy of muonic hydrogen [1,2] yielded a proton rms charge radius
which is 4% (or ~6 sigmas) smaller than the CODATA value [3]. Also the deuteron
charge radius from muonic deuterium [4] is 6 sigmas smaller than the CODATA
value, but consistent with the smaller proton inside the deuteron.

These smaller charge radii, when combined with precision measurements of the
1S-2S transitions in regular (electronic) hydrogen [5] and deuterium [6], yield
a 6 sigmas smaller value of the Rydberg constant [7], compared to the CODATA value.

In this talk I will report about a new measurement of the Rydberg constant from
the 2S-4P transition in regular hydrogen performed in Garching [8], which
supports the smaller, "muonic" value. I will also discuss the measurements in
muonic hydrogen, deuterium, and helium, and the consequences for the "proton
radius puzzle".

[1] Pohl et al. (CREMA Coll.), Nature 466, 213 (2010)
[2] Antognini et al. (CREMA Coll.), Science 339, 417 (2013)
[3] Mohr et al. (CODATA 2014), Rev. Mod. Phys. 88, 035009 (2016)
[4] Pohl et al. (CREMA Coll.), Science 353, 669 (2016)
[5] Parthey et al., PRL 107, 203001 (2011)
[6] Parthey et al., PRL 104, 233001 (2010)
[7] Pohl et al., Metrologia 54, L1 (2017)
[8] Beyer et al., Science 358, 79 (2017)

Primary author

Prof. Randolf Pohl (Johannes Gutenberg University Mainz)

Presentation Materials

Your browser is out of date!

Update your browser to view this website correctly. Update my browser now

×