2015/03/31 by Vladyslav Pauk, Marc Vanderhaeghen · 4 citations
Chemistry · Engineering · Physics and Astronomy · #Atomic and Molecular Physics #Atomic physics #Charge (physics) #Charge radius #Computer science #Electron #Lepton #Mass Spectrometry Techniques and Applications #Muon and positron interactions and applications #Nuclear physics #Particle physics #Physics #Proton #Quantum mechanics #RADIUS #Universality (dynamical systems) #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevlett.115.221804
published as Phys. Rev. Lett. 115, 221804 (2015) · 4 pages, 4 figures, version to be published in Phys. Rev. Lett
arxiv created 2015/11/11 · openalex publication_date 2015/11/25 · arxiv updated 2015/12/02 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
In view of the significantly different proton charge radius extracted from muonic hydrogen Lamb shift measurements as compared to electronic hydrogen spectroscopy or electron-scattering experiments, we study in this Letter the photoproduction of a lepton pair on a proton target in the limit of very small momentum transfer as a way to provide a test of the lepton universality when extracting the proton charge form factor. By detecting the recoiling proton in the \ensuremathγp\ensuremath→l^\ensuremath-l+p reaction, we show that a measurement of a ratio of e^\ensuremath-e++\ensuremathμ^\ensuremath-\ensuremathμ+ over e^\ensuremath-e+ cross sections with an absolute precision of 7\ifmmode×\else\texttimes\fi10^\ensuremath-4 would allow for a test to distinguish, at the 3\ensuremathσ level, between the two different proton charge radii currently extracted from muonic and electronic observables.