International collaboration CREMA - Charge Radius Experiments with Muonic Atoms General goals:  Laser spectroscopy of muonic atoms  Determination of the Lamb shift and assessment of the nuclear size and other nuclear properties. Coimbra, May 15, 20141

CREMA – Portuguese team LIBPhys LIBPhys – Laboratory for Instrumentation, Biomedical Engineering and Radiation Physics  LIBPhys-UC: 2 senior, 2 postdoc, 1 PhD student, 1 technician  LIBPhys-UNL: 1 senior, 1 postdoc, 1 PhD student I3N, University of Aveiro  1 senior researcher Coimbra, May 15, 20142

CREMA – Portuguese team Coimbra, May 15, 20143

Team responsibilities LIBPhys:  To use their expertize in radiation detectors to develop X-ray detectors needed for the several experiments.  Contributing to other collaboration tasks, including slow control, participation in scientific runs and data analysis. I3N:  Participation in the scientific runs. Coimbra, May 15, 20144

PTDC/FIS/82006/2006 ( €)  Characterization of avalanche photodiodes for application to the muonic hydrogen and muonic helium Lamb shift experiments PTDC/FIS/102110/2008 ( €)  Muonic helium Lamb shift and precision tests of quantum electrodynamics PTDC/FIS-NUC/0843/2012 ( €)  Participation in the international collaboration CREMA to measure the muonic helium Lamb shift Funding (FCT/COMPETE) Coimbra, May 15, 20145

Accomplished:  Muonic hydrogen Lamb shift experiment: the Portuguese team was responsible for the detection system for 2 keV X-rays, made of 20 avalanche photodiodes.  Muonic helium Lamb shift experiment: the X-ray detection system was optimized for 8 keV X-rays. New preamplifier system developed. Undergoing:  Muonic helium Lamb shift experiment: data analysis.  Preparation of the next experiment (muonic lithium). New detectors needed for 18 keV X-rays. Activities Coimbra, May 15, 20146

Main achievement: proton size Coimbra, May 15, 20147

1. The size of the proton, R. Pohl et al., Nature 466 (2010) The Lamb shift in muonic hydrogen, R. Pohl et al., Can. J. Phys. 89 (2011) Illuminating the proton radius conundrum: the μHe + Lamb shift, A. Antognini et al., Can. J. Phys. 89 (2011) Is the proton radius a player in the redefinition of the International System of Units?, F. Nez et al., Phil. Trans. R. Soc. A 369 (2011) Proton Structure from the Measurement of 2S-2P Transition Frequencies of Muonic Hydrogen, A. Antognini et al., Science 339 (2013) 417. Publications Coimbra, May 15, 20148

6. Laser spectroscopy of muonic hydrogen, R. Pohl et al., Ann. Phys.-Berlin 525 (2013) Lifetime and population of the 2S state in muonic hydrogen and deuterium, M. Diepold et al., Phys. Rev. A 88 (2013) Reach-Through Avalanche Photodiodes in Soft X-ray detection, A.L. Gouvea, A. Antognini, F. Kottmann, R. Pohl and L.M.P. Fernandes, IEEE Trans. Nucl. Sci. 61 (2014) Energy Resolution Contributions in Reach-Through Avalanche Photodiodes, A.L. Gouvea and L.M.P. Fernandes, IEEE Trans. Nucl. Sci. 61 (2014) Improved X-ray detection and particle identification with avalanche photodiodes, M. Diepold et al., accepted for publication in Rev. Sci. Instrum. (2015). Publications Coimbra, May 15, 20149

PhD Thesis:  Lamb shift in muonic helium: X-ray detection system, Andrêa Leite Gouvêa, PhD in Physics Engineering (January 2015). Article in a Portuguese magazine:  “O enigma do raio do protão”, L.M.P. Fernandes, Gazeta da Física 36 (2013) 2-5. Other publications Coimbra, May 15,

 RMD Avalanche Photodiodes for X-ray Detection in the Muonic Hydrogen Lamb Shift Experiment, L.M.P. Fernandes, European Conference on X-ray Spectrometry, Figueira da Foz, Portugal, June  Muonic hydrogen Lamb shift and proton size, 17th National Conference of Physics, L.M.P. Fernandes, University of Trás-os- Montes e Alto Douro, Vila Real, Portugal, 1-3 September  Energy Resolution Contributions in Reach-Through Avalanche Photodiodes, L.M.P. Fernandes, 2012 IEEE Nuclear Science Symposium - Conference Record (2012) 415.  Reach-through APDs for X-ray detection, A.L. Gouvea, 2012 IEEE Nuclear Science Symposium - Conference Record (2012) 424. Presentations Coimbra, May 15,

 Publication of the results of the muonic helium Lamb shift experiment after the data analysis is complete.  Help to solve the proton radius puzzle.  R&D for the muonic lithium Lamb shift experiment: selection of suitable detectors and respective amplifiers.  Setup of the experiment and scientific run. Prospects for the near future Coimbra, May 15,