Initial quantum levels of captured muons in CO, CO2, and COS

  • Go YoshidaEmail author
  • Kazuhiko Ninomiya
  • Makoto Inagaki
  • Wataru Higemoto
  • Patrick Strasser
  • Naritoshi Kawamura
  • Koichiro Shimomura
  • Yasuhiro Miyake
  • Taichi Miura
  • Kenya M. Kubo
  • Atsushi Shinohara


The role of valence electrons for the muon capture process by molecules is experimentally investigated with the aid of cascade calculations. Low-momentum muons are introduced to gas targets of CO, CO2, and COS below atmospheric pressure. The initial states of captured muons are determined from the measured muonic X-ray structure of the Lyman and Balmer series. We propose that the lone pair electrons in the carbon atom of CO significantly contribute to the capture of a muon with large angular momenta.


Muon Muonic atom Muon capture Muonic X-ray Carbon oxide 



Experiments were performed at the Materials and Life Science Experimental Facility of J-PARC under user programs (Proposal Nos. 2012A0039 and 2012B0103). This study was partially supported by a JSPS KAKENHI (Grant Numbers 26800213 and 261738).


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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2019

Authors and Affiliations

  • Go Yoshida
    • 1
    • 2
    Email author
  • Kazuhiko Ninomiya
    • 2
  • Makoto Inagaki
    • 2
  • Wataru Higemoto
    • 3
  • Patrick Strasser
    • 4
  • Naritoshi Kawamura
    • 4
  • Koichiro Shimomura
    • 4
  • Yasuhiro Miyake
    • 4
  • Taichi Miura
    • 1
  • Kenya M. Kubo
    • 5
  • Atsushi Shinohara
    • 2
  1. 1.Radiation Science CenterHigh Energy Accelerator Research Organization (KEK)TsukubaJapan
  2. 2.Graduate School of ScienceOsaka UniversityToyonakaJapan
  3. 3.Japan Atomic Energy AgencyTokai, NakaJapan
  4. 4.Muon Science LaboratoryHigh Energy Accelerator Research Organization (KEK)TsukubaJapan
  5. 5.International Christian UniversityMitakaJapan

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