# Physics of fundamental Symmetries and Interactions - PSI2019

20-25 October 2019
PSI
Europe/Zurich timezone

## The proton radius puzzle

22 Oct 2019, 11:00
45m
WHGA/001 - Auditorium (PSI)

Invited Talk

### Speaker

Aldo Antognini (ETH)

### Description

By means of laser spectroscopy we have measured several 2S-2P transitions in muonic hydrogen. From these measurements we have extracted a proton charge radius 20 times more precise than obtained from electron-proton scattering and hydrogen high-precision laser spectroscopy but at a variance of 7 sigma from these values. This discrepancy referred to as the proton radius puzzle’’ has prompted various investigations in the context of bound-state QED, proton structure, atomic spectroscopy, BSM physics and scattering experiments.
The status of the "proton radius puzzle" will be presented.