Related papers: Possible Beyond the Standard Model Physics Motivat…
Background: The recent disagreement between the proton charge radius extracted from Lamb shift measurements of muonic and electronic hydrogen invites speculation that new physics may be to blame. Several proposals have been made for new…
A measurement of the Lamb shift in muonic hydrogen yields a charge radius of the proton that is smaller than the CODATA value by about 5 standard deviations. We explore the possibility that new scalar, pseudoscalar, vector, and tensor…
The proton radius puzzle, the discrepancy between the proton radius measured in muonic hydrogen and electronic hydrogen, has yet to be resolved. There are suggestions that beyond the standard model (BSM) physics could resolve both this…
A persistence of several anomalies in muon physics, such as the muon anomalous magnetic moment and the muonic hydrogen Lamb shift, hints at new light particles beyond the Standard Model. We address a subset of these models that have a new…
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 scattering off the proton on the one side and the high…
Currently, both the g factor measurement of the muon as well as the Lamb shift 2S-2P measurement in muonic hydrogen are in disagreement with theory. Here, we investigate possible theoretical explanations, including proton structure effects…
Reinforcement of the puzzle about the proton charge radius r, stimulated by the recent experiments with muonic hydrogen induced news discussions on the subject, and now some physicists are ready to adopt the exotic properties of muon, lying…
The discrepancy between the measured Lamb shift in muonic hydrogen and expectations from electron-proton scattering and regular hydrogen spectroscopy has become known as the proton radius puzzle, whose most "mundane" resolution requires a…
The proton radius has been measured in electron-proton scattering experiments and laser based spectroscopy of muonic hydrogen. The latter method is based on the precise calculations for the atomic energy levels in the approximation of…
The "proton size puzzle" and the "muon anomalous moment problem" are incomplete descriptions of significant discrepancies of Standard Model calculations with experiments. What is particularly new is that the experiments and theory confront…
The proton radius puzzle remains a key challenge in modern physics, highlighting both the precision and limitations of current experimental and theoretical approaches. Recent studies, such as those by Xiong et al. and Bezginov et al., have…
A summary is given of the present status of the theory and experiment of the anomalous magnetic moment of the muon. A difference between predicted and measured values is an indication of physics beyond the Standard Model. A new experimental…
We explore the possibility that a new interaction between muons and protons is responsible for the discrepancy between the CODATA value of the proton radius and the value deduced from the measurement of the Lamb shift in muonic hydrogen. We…
The Proton Radius Puzzle is the inconsistency between the proton radius determined from muonic hydrogen and the proton radius determined from atomic hydrogen level transitions and ep elastic scattering. No generally accepted resolution to…
The proton charge radius extracted from the recent muonic hydrogen spectroscopy [Antognini et al. 2013; Pohl et al. 2010] differs from the CODATA 2010 recommended value [Mohr et al. 2012] by more than 4% or $4.4 \sigma$. This discrepancy,…
In 2010 the proton charge radius was extracted for the first time from muonic hydrogen, a bound state of a muon and a proton. The value obtained was five standard deviations away from the regular hydrogen extraction. Taken at face value,…
Pohl et al. measured the energy difference between the 2P and 2S states of muonic hydrogen and used it to determine a precise value of the proton radius. The result disagreed significantly from values extracted from electronic hydrogen and…
I provide a (personal) review of the current hints for physics beyond the Standard Model, called ``anomalies'', obtained both at the intensity frontier (flavour and electroweak precision observables) and in direct LHC searches. This…
The proton charge radius inferred from muonic hydrogen spectroscopy is not compatible with the previous value given by CODATA-2010, which, on its turn, essentially relies on measurements of the electron-proton interaction. The proton's new…
A possible explanation for the discrepancy between electronic and muonic hydrogen measurements of the proton charge radius are new, lepton-universality violating interactions. Several new couplings and particles have been suggested that…