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Welcome

The international workshop on the theoretical and experimental approaches for nuclear matrix elements of double-beta decay will be held on December 21 and 22, 2023 in Research Center for Nuclear Study, Osaka University, Japan.

The discovery of the neutrinoless double-beta (0νββ) decay gives the proof of the existence of a Majorana neutrino, which is a decisive clue to solving the mystery of the birth of the matter-prevailing universe. The 0νββ decay is also quite important for determining the ordering structure of the neutrino eigen masses. In the recent future plans for the 0νββ decay experiments, the searches for the decay in the inverted ordering region (the mass of 10-20 meV) and the normal ordering region (the mass of several meV) are proposed. The prediction of the nuclear matrix element (NME) is necessary for determining the effective neutrino mass from the measured half-life of the decay. This is a challenging task for theoretical nuclear physics because the 0νββ decay is a qualitatively unprecedented and extremely rare phenomenon. Currently, the calculated NMEs are distributed in a broad ratio range of 2–3.

The aim of this workshop is to improve the accuracy of the theoretical NME calculation. Close cooperation between the experimentalists and the theorists is necessary to achieve this aim. A question is what measurements can be important inputs to the NME calculation. The discussions are expected on the requests and suggestions for new experimental measurements.

The discussion will also be made on the measurement results of the phenomena related to the 0νββ decay as the precise measurement of the half-life of the 2νββ decay, the double Gamow-Teller transition strength using the double-charge exchange reaction, and other physical quantities for obtaining important insight through the measurements of the nuclear reactions using accelerators.

Workshop information;

• Date : 21 st(Thu) - 22 nd(Fri.), December, 2023
• Place : Research Center for Nuclear Physics(RCNP), Osaka University & zoom

Subjects to be discussed;

• theoretical NME calculation
  • half-life of the 2νββ decay
  • double Gamow-Teller transition strength using the double-charge exchange reaction
  • measurements of the nuclear reactions using accelerators

We look forward to seeing you in RCNP in December 2023.

Support

The workshop NME23 is supported by

• Grant-in-Aid for Scientific Research on Innovative Areas "Revealing the history of the universe and matter evolution with underground physics"
• Research Center for Nuclear Physics(RCNP)