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Related papers: Possible Beyond the Standard Model Physics Motivat…

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High-precision measurements of the proton radius from laser spectroscopy of muonic hydrogen demonstrated up to six standard deviations smaller values than obtained from electron-proton scattering and hydrogen spectroscopy. The status of…

A new scalar boson which couples to the muon and proton can simultaneously solve the proton radius puzzle and the muon anomalous magnetic moment discrepancy. Using a variety of measurements, we constrain the mass of this scalar and its…

High Energy Physics - Phenomenology · Physics 2016-09-13 Yu-Sheng Liu , David McKeen , Gerald A. Miller

We study in an effective operator approach how the effects of new physics from various scenarios that contain an extra $Z'$ neutral gauge boson or doubly charged scalars, can affect and thus be tested by the precision polarized M\o{}ller…

High Energy Physics - Phenomenology · Physics 2009-11-13 We-Fu Chang , John N. Ng , Jackson M. S. Wu

Lepton-nucleon elastic scattering, using the one-photon and one-scalar-boson exchange mechanisms considering all possible polarizations, is used to study searches for a new scalar boson and suggest new measurements of the nucleon form…

Nuclear Theory · Physics 2015-10-07 Yu-Sheng Liu , Gerald A. Miller

The recently reported measurement of the muon's anomalous magnetic moment differs from the standard model prediction by 2.6 standard deviations. We examine the implications of this discrepancy for supersymmetry. Deviations of the reported…

High Energy Physics - Phenomenology · Physics 2009-10-09 Jonathan L. Feng , Konstantin T. Matchev

In recent years, exciting (indirect) hints for physics beyond the Standard Model (SM) have been accumulated. In particular, semi-leptonic $B$ decays show deviations from the SM predictions, which, due to the ratios $R(K^{(*)})$ and…

High Energy Physics - Phenomenology · Physics 2022-04-27 Andreas Crivellin , Joaquim Matias

A confirmation of the long-standing muon $g$-2 discrepancy requires both experimental and theoretical progress. On the theory side, the hadronic corrections are under close scrutiny, as they induce the leading uncertainty of the Standard…

High Energy Physics - Phenomenology · Physics 2020-10-21 A. Masiero , P. Paradisi , M. Passera

Since its inception, no decisive departure from the predictions of Standard Model (SM) has been reported. But recently various experiments have observed few hints of possible departure from SM predictions in lepton flavor universality…

High Energy Physics - Phenomenology · Physics 2019-09-06 Lobsang Dhargyal

We present a new experiment, Mu-MASS, aiming for a 1000-fold improvement in the determination of the 1S-2S transition frequency of Muonium (M), the positive-muon/electron bound state. This substantial improvement beyond the current…

Atomic Physics · Physics 2018-12-05 P. Crivelli

The recent discrepancy between proton charge radius measurements extracted from electron-proton versus muon-proton systems is suggestive of a new force that differentiates between lepton species. We identify a class of models with gauged…

High Energy Physics - Phenomenology · Physics 2011-07-28 Brian Batell , David McKeen , Maxim Pospelov

Systematic differences in the the proton's charge radius, as determined by ordinary atoms and muonic atoms, have caused a resurgence of interest in elastic lepton scattering measurements. The proton's charge radius, defined as the slope of…

We review the role of the anomalous magnetic moment of the muon a_\mu as a powerful probe of physics beyond the Standard Model (BSM), taking advantage of the final result of the Fermilab g-2 experiment and the recently updated Standard…

High Energy Physics - Phenomenology · Physics 2026-02-27 Peter Athron , Kilian Möhling , Dominik Stöckinger , Hyejung Stöckinger-Kim

The current experimental values of anomalous magnetic moments of muon and electron deviate from the Standard Model predictions by few standard deviations, which might be a hint of new physics. The sizes and signs of these deviations are…

High Energy Physics - Phenomenology · Physics 2019-10-23 Marcin Badziak , Kazuki Sakurai

We propose a theoretical scenario to solve the proton radius puzzle which recently arises from the muonic hydrogen experiment. In this framework, 4 + n dimensional theory is incorporated with modified gravity. The extra gravitational…

High Energy Physics - Phenomenology · Physics 2013-06-27 Li-Bang Wang , Wei-Tou Ni

Muon electron scattering experiments such as the proposed MUonE experiment, offer an opportunity for an improved measurement of the Leading Order hadronic running of $\alpha$, denoted $\Delta \alpha_{\rm{had}}$. Such a measurement could be…

High Energy Physics - Phenomenology · Physics 2019-09-04 Ulrich Schubert , Ciaran Williams

The measurements of the muon and electron anomalous magnetic moments hint at physics beyond the standard model. We show why and how models inspired by asymptotic safety can explain deviations from standard model predictions naturally. Our…

High Energy Physics - Phenomenology · Physics 2020-10-21 Gudrun Hiller , Clara Hormigos-Feliu , Daniel F. Litim , Tom Steudtner

We show that off-mass-shell effects arising from the internal structure of the proton provide a new proton polarization mechanism in the Lamb shift, proportional to the lepton mass to the fourth power. This effect is capable of resolving…

Atomic Physics · Physics 2015-05-27 G. A. Miller , A. W. Thomas , J. D. Carroll , J. Rafelski

Background: The "proton radius puzzle" refers to an eight-year old problem that highlights major inconsistencies in the extraction of the charge radius of the proton from muonic Lamb-shift experiments as compared against experiments using…

Nuclear Theory · Physics 2019-05-22 Shuang Zhou , P. Giuliani , J. Piekarewicz , Anirban Bhattacharya , Debdeep Pati

A model-agnostic search for Beyond the Standard Model physics is presented, targeting final states with at least four light leptons (electrons or muons). The search regions are separated by event topology and unsupervised machine learning…

High Energy Physics - Experiment · Physics 2026-03-23 ATLAS Collaboration

In this letter, we address the question of whether the almost four standard deviations difference between theory and experiment for the muon anomalous magnetic moment $a_\mu$ can be explained as a higher-order Standard Model perturbation…

High Energy Physics - Phenomenology · Physics 2019-10-16 Francisco Campanario , Henryk Czyż , Janusz Gluza , Tomasz Jeliński , Germán Rodrigo , Szymon Tracz , Dmitry Zhuridov