scholarly journals The Muon Scattering Experiment (MUSE) at PSI and the proton radius puzzle

2014 ◽  
Vol 81 ◽  
pp. 02008 ◽  
Author(s):  
Michael Kohl
Author(s):  
Ethan Cline ◽  
Jan Bernauer ◽  
Evangeline J. Downie ◽  
Ronald Gilman

MUSE is a high-precision muon scattering experiment aiming to determine the proton radius. Muon, electron, and pion scattering will be measured at the same time. Two-photon exchange corrections will be determined with data using both beam polarities.


Author(s):  
Clara Peset ◽  
Antonio Pineda ◽  
Oleksandr Tomalak

2011 ◽  
Vol 89 (1) ◽  
pp. 47-57 ◽  
Author(s):  
A. Antognini ◽  
F. Biraben ◽  
J. M.R. Cardoso ◽  
D. S. Covita ◽  
A. Dax ◽  
...  

We plan to measure several 2S–2P transition frequencies in μ4He+ and μ3He+ by means of laser spectroscopy with an accuracy of 50 ppm. This will lead to a determination of the corresponding nuclear rms charge radii with a relative accuracy of 3 × 10−4, limited by the uncertainty of the nuclear polarization contribution. First, these measurements will help to solve the proton radius puzzle. Second, these very precise nuclear radii are benchmarks for ab initio few-nucleon theories and potentials. Finally when combined with an ongoing measurement of the 1S–2S transition in He+, these measurements will lead to an enhanced bound-state QED test of the 1S Lamb shift in He+.


2014 ◽  
Vol 81 ◽  
pp. 01009 ◽  
Author(s):  
Miha Mihovilovič ◽  
Harald Merkel ◽  
Adrian Weber

Nature ◽  
2019 ◽  
Vol 575 (7781) ◽  
pp. 61-62
Author(s):  
Jean-Philippe Karr ◽  
Dominique Marchand

2014 ◽  
Vol 23 (12) ◽  
pp. 1450090 ◽  
Author(s):  
D. Robson

The relationship between the static electric form factor for the proton in the rest frame and the Sachs electric form factor in the Breit momentum frame is used to provide a value for the difference in the mean squared charge radius of the proton evaluated in the two frames. Associating the muonic–hydrogen data analysis for the proton charge radius of 0.84087 fm with the rest frame and associating the electron scattering data with the Breit frame yields a prediction of 0.87944 fm for the proton radius in the relativistic frame. The most recent value deduced via electron scattering from the proton is 0.877(6) fm so that the frame dependence used here yields a plausible solution to the proton radius puzzle.


Science ◽  
2020 ◽  
Vol 370 (6520) ◽  
pp. 1061-1066 ◽  
Author(s):  
Alexey Grinin ◽  
Arthur Matveev ◽  
Dylan C. Yost ◽  
Lothar Maisenbacher ◽  
Vitaly Wirthl ◽  
...  

We have performed two-photon ultraviolet direct frequency comb spectroscopy on the 1S-3S transition in atomic hydrogen to illuminate the so-called proton radius puzzle and to demonstrate the potential of this method. The proton radius puzzle is a significant discrepancy between data obtained with muonic hydrogen and regular atomic hydrogen that could not be explained within the framework of quantum electrodynamics. By combining our result [f1S-3S = 2,922,743,278,665.79(72) kilohertz] with a previous measurement of the 1S-2S transition frequency, we obtained new values for the Rydberg constant [R∞ = 10,973,731.568226(38) per meter] and the proton charge radius [rp = 0.8482(38) femtometers]. This result favors the muonic value over the world-average data as presented by the most recent published CODATA 2014 adjustment.


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