Jan 21 – 25, 2019
Bormio, Italy
Europe/Berlin timezone

News from the "proton radius puzzle"

Jan 22, 2019, 11:00 AM
30m
Bormio, Italy

Bormio, Italy

Short Contribution Tuesday Morning Session

Speaker

Prof. Randolf Pohl (Johannes Gutenberg University Mainz)

Description

For more than eight years now, the "proton radius puzzle" has let us dream about new physics: Our measurements of muonic hydrogen and muonic deuterium, performed in the CREMA Collabroation at PSI, yielded a proton radius which is more than five standard deviations smaller than the CODATA world average from measurements using electrons, namely precision spectroscopy of atomic hydrogen and deuterium, and elastic electron scattering. A wealth of new experiments has been fueled by this exciting discrepancy, and the first results are now coming in. I will report on several new measurements in atomic hydrogen we have performed at MPQ Garching. These, together with new hydrogen measurements from LKB Paris and York U. Toronto and new elastic electron scattering data from The PRad experiment at Jefferson Lab start to paint a clearer picture on the "proton radius puzzle", albeit not without raising new questions.

Summary

For more than eight years now, the "proton radius puzzle" has let us dream
about new physics: Our measurements of muonic hydrogen and muonic deuterium,
performed in the CREMA Collabroation at PSI, yielded a proton radius which is
more than five standard deviations smaller than the CODATA world average from
measurements using electrons, namely precision spectroscopy of atomic hydrogen
and deuterium, and elastic electron scattering.

A wealth of new experiments has been fueled by this exciting discrepancy, and
the first results are now coming in. I will report on several new measurements
in atomic hydrogen we have performed at MPQ Garching. These, together with new
hydrogen measurements from LKB Paris and York U. Toronto and new elastic
electron scattering data from The PRad experiment at Jefferson Lab start to
paint a clearer picture on the "proton radius puzzle", albeit not without
raising new questions.

Primary author

Prof. Randolf Pohl (Johannes Gutenberg University Mainz)

Presentation materials