Speaker
Description
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.
