Year: 2025
Type: article
Abstract: The FAMU experiment, supported and funded by the Italian Institute of Nuclear Physics (INFN) and by the Science and Technology Facilities Council (STFC), aims to perform the first measurement of the ground-state hyperfine splitting ( 1S-hfs ) of muonic hydrogen ( $$\mu H$$ μ H ). This quantity is highly sensitive to the proton’s Zemach radius $$R_Z$$ R Z . An experimental determination of $$R_Z$$ R Z provides significant constraints on the parametrisation of the proton form factors as well as on theoretical models describing the proton’s electromagnetic structure. Following years of technological and methodological development, the FAMU experiment began operations in 2023 at Port 1 of the RIKEN-RAL muon beam line at the ISIS Neutron and Muon Source facility (Didcot, UK). In this paper, we first describe the unique detection technique employed by FAMU to determine the 1S-hfs of muonic hydrogen, followed by a detailed presentation of the final experimental layout. Finally, we report the first outcome from the 2023 commissioning run and from the initial physics runs performed in 2023 and 2024.
Source: The European Physical Journal A
Authors: A. Adamczak, D. Bakalov, G. Baldazzi, M. Baruzzo, R. Benocci, R. Bertoni, M. Bonesini, S. Capra, D. Cirrincione, M. Clemenza, L. Colace, M. Danailov, P. Danev, A. de Bari, C. De Vecchi, D. Di Ferdinando, E. Fasci, R. Gaigher, L. Gianfrani, A. D. Hillier, K. Ishida, J. S. Lord, A. Menegolli, E. Mocchiutti, S. Monzani, L. Moretti, G. Morgante, C. Pizzolotto, A. Pullia, M. Pullia, R. Ramponi, H. E. Roman, M. Rossella, R. Rossini, A. Sbrizzi, M. Stoilov, J. J. Suárez-Vargas, G. Toci, L. Tortora, E. Vallazza, K. Yokoyama, A. Vacchi
Institutions: Institute of Nuclear Physics, Polish Academy of Sciences, Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy, Istituto Nazionale di Fisica Nucleare, Sezione di Bologna, University of Bologna, Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca, University of Milano-Bicocca, University of Milan, Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Roma Tre University, Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tre, Elettra-Sincrotrone Trieste S.C.p.A., University of Pavia, Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, University of Campania "Luigi Vanvitelli", Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Rutherford Appleton Laboratory, ISIS Neutron and Muon Source, RIKEN Nishina Center, University of Udine, Osservatorio di Astrofisica e Scienza dello Spazio, National Institute for Astrophysics, National Center for Oncological Hadrontherapy, Politecnico di Milano
Language: English
Topic: Atomic and Molecular Physics
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,990
Funders: Florida Agricultural and Mechanical University, Abdus Salam International Centre for Theoretical Physics, Bulgarian National Science Fund, Università degli Studi di Pavia, Ministero dell'Università e della Ricerca, Science and Technology Facilities Council, Instituto Nazionale di Fisica Nucleare, RIKEN, Nuclear Physics, ISIS Neutron and Muon Source
OpenAlex ID: W4414596450