The FAMU experiment at RIKEN-RAL for high-precision HFS muon spectroscopy
Year: 2026
Authors: Bonesini M., Benocci R., Adamczak A., Bakalov D., Baldazzi G., Baruzzo M., Bertoni R., Capra S., Cirrincione D., Clemenza M., Colace L., Danailov M., Danev P., de Bari A., De Vecchi C., Di Ferdinando D., Fasci E., Gaigher R., Gianfrani L., Hillier AD., Ishida K., Lord JS., Menegolli A., Mocchiutti E., Monzani S., Moretti L., Morgante G., Pizzolotto C., Pullia A., Pullia M., Ramponi R., Roman HE., Rossella M., Rossini R., Sbrizzi A., Stoilov M., Subrez-Vargas JJ., Toci G., Tortora L., Vallazza E., Yokoyama K., Vacchi A.
Autors Affiliation: Univ Milano Bicocca, Dipartimento Fis, Piazza Sci 3, I-20126 Milan, Italy; Polish Acad Sci, Inst Nucl Phys, Radzikowskiego 152, Krakow, Poland; Bulgarian Acad Sci, INRNE, 72 Tzarigradsko Chaussee Blvd, BU-1784 Sofia, Bulgaria; Univ Bologna, Dipartimento Fis & Astron, Viale Berti Pichat 6-2, Bologna, Italy; Sez INFN Trieste, Via A Valerio 2, Trieste, Italy; INFN, Sez Milano, Via Celoria 16, Milan, Italy; Univ Roma Tre, Dipartimento Matemat & Fis, Sez Roma Tre, Via Vasca Navale 84, I-00146 Rome, Italy; Univ Pavia, Dipartimento Fis A Volta, Via A Bassi 6, I-27100 Pavia, Italy; Univ Campania L Vanvitelli, Sez INFN Napoli, Viale Lincoln 5, Caserta, Italy; Univ Campania L Vanvitelli, Dipartimento Fis, Viale Lincoln 5, Caserta, Italy; STFC Rutherford Appleton Lab, ISIS Neutron, Muon Source, Didcot, England; RIKEN, Riken Nishina Ctr, 2-1 Hirosawa, Wako, Saitama, Japan; Univ Udine, Dipartimento Sci Matematiche Informat & Fis, Via Sci 206, Udine, Italy; Politecn Milan, FN CNR, Piazza Leonardo Vinci 32, Milan, Italy; Politecn Milan, Dipartimento Fis, Piazza Leonardo Vinci 32, Milan, Italy; INO CNR, Via Madonna Piano 10, Sesto Fiorentino, Italy; Sincrotrone Elettra Trieste, Basovizza, Italy; INAF OAS Bologna, Bologna, Italy; Ctr Nazl Adroterapia Oncolog CNAO, Pavia, Italy.
Abstract: The FAMU experiment at RIKEN-RAL aims to measure with high precision the ground state hyperfine splitting (1S HFS) of muonic hydrogen and thus determine the proton Zemach radius. A novel method based on the detection of X-rays emitted by & micro;O after the muon transfer from & micro;H to oxygen is used. A high performance X-ray detectors’ system and an innovative mid-infrared (MIR) laser system were therefore developed. The X-ray detector’s system is mainly based on LaBr3:Ce crystals read by SiPM arrays. From the MIR laser frequency value, known with precision < 10(-5), the energy of the HFS transition may be accurately measured, as Delta E-HFS = h nu(HFS). Journal/Review: JOURNAL OF INSTRUMENTATION
Volume: 21 (1) Pages from: C01029-1 to: C01029-13
KeyWords: Gamma detectors (scintillators, CZT, HPGe, HgI etc); Muon spectrometersDOI: 10.1088/1748-0221/21/01/C01029
