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 couplings to the electron, muon, neutron, and proton. Making no assumptions about the underlying model, these constraints and the requirement that it solve both problems limit the mass of the scalar to between about 100 keV and 100 MeV. We identify two unexplored regions in the coupling constant-mass plane. Potential future experiments and their implications for theories with mass-weighted lepton couplings are discussed.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.117.101801 | DOI Listing |
Eur Phys J C Part Fields
November 2024
ETH Zürich, Institute for Particle Physics and Astrophysics, 8093 Zurich, Switzerland.
Eur Phys J C Part Fields
November 2024
Department of Physics, University of Wisconsin, Madison, WI 53706 USA.
Eur Phys J C Part Fields
October 2024
Bogoliubov Laboratory of Theoretical Physics, JINR, 141980 Dubna, Russia.
In this study, we demonstrate the potential of the NA64 experiment at CERN SPS to search for New Physics processes involving transitions after the collision of 100 GeV electrons with target nuclei. A new Dark Sector leptonic portal in which a scalar boson could be produced in the lepton-flavor-changing bremsstrahlung-like reaction, , is used as benchmark process. In this work, we develop a realistic Monte Carlo simulation of the NA64 experimental setup implementing the differential and total production cross-section computed at exact tree-level and applying the Weiszäcker-Williams phase space approximation.
View Article and Find Full Text PDFPhys Rev Lett
September 2024
CENTRA, Departamento de Física, Instituto Superior Técnico-IST, Universidade de Lisboa-UL, Avenida Rovisco Pais 1, 1049 Lisboa, Portugal.
Previous works have argued that future gravitational-wave detectors will be able to probe the properties of astrophysical environments where binaries coalesce, including accretion disks, but also dark matter structures. Most analyses have resorted to a Newtonian modeling of the environmental effects, which are not suited to study extreme-mass-ratio inspirals immersed in structures of ultralight bosons. In this Letter, we use relativistic perturbation theory to consistently study these systems in spherical symmetry.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!