EDM Measurement with Ultracold Neutrons

Friday 29 May 2015, 11:00 → 12:00 Asia/Tokyo

RIBF Bldg. 2F Coference room (RIKEN Wako)

RIKEN Seminar: EDM Measurement with Ultracold Neutrons Date May 29, 2015 Time 11:00-12:00 Target Researchers Location RIBF Bldg, Large Conference room (changed!) 2-1 Hirosawa, Wako, Saitama, Japan Language English Speaker Prof. Yasuhiro Masuda (High Energy Accelerator Research Organization, KEK) Abstract: CP violation is one of important issues in particle physics. The CP violation induces an electric dipole moment in the neutron (nEDM). With nEDM, many theories of particle physics have been tested. Although the standard model predicts very small values of nEDM, new physics such as supersymmetric theory as well as multi-Higgs model, which is beyond the standard model, predicts nEDM values in a 10^{-27} e cm region. The present state of the arts nEDM measurement is at Grenoble, which shows the upper limit of 3×10^{-26} e cm. In this measurement, ultracold neutrons (UCN) was used. UCN are very low energy neutrons, which can be confined in a measurement cell. The precision of the measurement was limited by the number of UCN in the cell, but the improvement of the number of UCN was strongly limited by Liouville’s theorem. Many institutes have been developing super thermal UCN sources, which get rid of this limitation. Here, we discuss our approach to this problem. Our UCN source became world competitive. We also discuss the present status and the future direction of our nEDM measurement. Ref. Spallation UCN production in He-II for nEDM measurement (2013) E3 Project Seminar iTHES Next seminar(12:30-13:30) will start at 12:30 to review the current status of the dark matter research for non-specialists relating to the recent result of AMS. ---- Important remainder for the Pioneer project seminar: The location of the seminars has been changed from the Main Building to RIBF 2F conference room. Please note the location and join the seminars.