| DATE: |
2006-05-16 16:00 - 17:00 |
| PLACE: |
Room 345 of Building 4 |
| TITLE: |
Physics Seminar: MOON for double beta decays and Majorana neutrino masses |
| CONTACT: |
shigeru.odaka kek.jp, 4342 |
| SPEAKER: |
Hiro Ejiri (JASRI SPring-8 and RCNP Osaka Univ.) |
| LANGUAGE: |
English |
| URL: |
http://seminar.kek.jp/physics/index.html |
| ABSTRACT: |
MOON (Molybdenum Observatory Of
Neutrinos) is a spectroscopic double
beta decay experiment with a mass sensitivity of >> 30 meV in the IH (Inverted Hierarchey) region. The MOON detector consists of multi-layer modules with plastic scintillator plates (PL) and enriched 100Mo foils. It is based on ELEGANT-V. Individual beta rays are measured to identify the neutrino-mass term. The MOON-1 detector was built as a prototype of the MOON detector to demonstrate feasibilities of the MOON detector with the IH mass sensitivity. The measurement using the MOON-1 detector is carried out at the Oto underground laboratory (1,400 m w.e.) since August 2005. The MOON-1 detector is placed inside the passive Cu-lead shields and active Nal shields of ELEGANT V. The energy resolution of PL is obtained by measuring Compton-scattered electrons at PL's and Compton scattered gamma rays at the NaI detector. The energy resolution for the PL is found to be around s = 2.9 % at Qbb (3.034 MeV). The 0nbb efficiency of around 40 % is achieved. These results show the feasibility of MOON with the IH mass sensitivity in views of the energy resolution and the efficiency. BG rejections are under progress. |
