Nuclear structure to unveil the nature of neutrinos and dark matter

2019 Fiscal Year Annual Research Report

• Project/Area Number: 18K03639
• Research Institution: The University of Tokyo
• Principal Investigator: Menendez Javier 東京大学, 大学院理学系研究科(理学部), 特任研究員 (70807635)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: Double-beta decay / Double electron capture / Ab initio calculations

Outline of Annual Research Achievements

In FY2019 we have accomplished the following main achievements:
* Publication of the first shell model prediction of the two-neutrino double electron capture nuclear matrix element of xenon-124.
* First principles calculation of the nuclear structure of nickel-78. A comparison with the results measured at RIBF RIKEN is published in the top journal Nature. This calculation is a first step towards first principles studies of the double-beta decay of germanium-76.
* First principles calculation of the nuclear structure of titanium-62. A comparison with the results measured at RIBF RIKEN is accepted for publication in Phys. Lett. B. This calculation is a first step towards first principles studies of the double-beta decay of calcium-48.

Research Products

• [Int'l Joint Research] Technical University Darmstadt(ドイツ)
  • Country Name: GERMANY
  • Counterpart Institution: Technical University Darmstadt
• [Int'l Joint Research] TRIUMF(カナダ)
  • Country Name: CANADA
  • Counterpart Institution: TRIUMF
• [Journal Article] Two-neutrino double electron capture on 124Xe based on an effective theory and the nuclear shell model (2019)
  • Author(s): E. A. Coello Perez, J. Menendez and A. Schwenk
  • Journal Title: Physics Letters B Volume: 797 Pages: 134885
  • DOI: 10.1016/j.physletb.2019.134885
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] 78Ni revealed as a doubly magic stronghold against nuclear deformation (2019)
  • Author(s): R. Taniuchi and SEASTAR collaboration, J. D. Holt, J. Menendez, F. Nowacki, K. Ogata, T. Otsuka, A. Poves, A. Schwenk, J. Simonis, S. R. Stroberg and Y. Tsunoda
  • Journal Title: Nature Volume: 569 Pages: 53
  • DOI: 10.1038/s41586-019-1155-x
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Shell evolution of N40 isotones towards 60Ca: First spectroscopy of 62Ti (2019)
  • Author(s): M. L. Cortes and SEASTAR collaboration, J. D. Holt, S. M. Lenzi, J. Menendez, F. Nowacki, K. Ogata, A. Poves, T. R. Rodriguez, A. Schwenk, J. Simonis and S. R. Stroberg, and K. Yoshida
  • Journal Title: Physics Letters B Volume: In print Pages: In print
  • DOI: In print
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Beta decay in the nuclear shell model: capabilities, limitations, uncertainties (2019)
  • Author(s): Javier Menendez
  • Organizer: ECT* Workshop “Precise beta decay calculations for searches for new physics”
  • Int'l Joint Research / Invited
• [Presentation] Relating double-beta decay to nuclear properties at hand (2019)
  • Author(s): Javier Menendez
  • Organizer: Neutrino Nuclear Responses for Double Beta Decays and Astro Neutrinos
  • Int'l Joint Research / Invited
• [Presentation] Nuclear physics and double-beta decay (2019)
  • Author(s): Javier Menendez
  • Organizer: Wilhelm und Else Heraeus-Seminar “Massive Neutrinos”
  • Int'l Joint Research / Invited
• [Presentation] Double-beta decay calculations: new tests and opportunities (2019)
  • Author(s): Javier Menendez
  • Organizer: INT Program “Nuclear Structure at the Crossroads”
  • Int'l Joint Research / Invited
• [Presentation] Neutrinoless double-beta decay: novel insights on nuclear matrix elements (2019)
  • Author(s): Javier Menendez
  • Organizer: International Nuclear Physics Conference, 2019
  • Int'l Joint Research / Invited