433 citations · 3.1k across the 63 of their papers we have counts for
63 papers
The Lamb shift in muonic hydrogen and the electric rms radius of the proton
Thomas Walcher
The "proton radius puzzle" is the 7-standard-deviations difference of the charge radius of the proton as determined from the Lamb shift in electronic hydrogen and elastic electron…
Measurement of the α-particle monopole transition form factor challenges theory: a low-energy puzzle for nuclear forces?
S. Kegel, P. Achenbach, S. Bacca +30
We perform a systematic study of the -particle excitation from its ground state to the resonance. The so-called monopole transition form factor is investigated v…
A short-orbit spectrometer for low-energy pion detection in electroproduction experiments at MAMI
D. Baumann, M. Ding, I. Friščić +7
A new Short-Orbit Spectrometer (SOS) has been constructed and installed within the experimental facility of the A1 collaboration at Mainz Microtron (MAMI), with the goal to detect…
Measurement of the reaction close to threshold and at low
A1 Collaboration, I. Friščić, P. Achenbach +21
The cross section of the reaction has been measured for five kinematic settings at an invariant mass of MeV and for a four-momentum transfer of $Q^2 = 0.07…
The end of the nucleon-spin crisis
Bogdan Povh, Thomas Walcher
The small fraction of the quark polarization of the nucleon obtained in deep inelastic lepton scattering is a consequence of a wrong assumption on the flux of polarized virtual pho…
Solution of the proton radius puzzle? Low momentum transfer electron scattering data are not enough
Michael O. Distler, Thomas Walcher, Jan C. Bernauer
In two recent papers it is argued that the 'proton radius puzzle' can be explained by truncating the electron scattering data to low momentum transfer and fit the rms radius in the…