Zoom (https://snu-ac-kr.zoom.us/j/5265861328?pwd=ZjlSSVE2QysyOFBWSnN1WDhndHREUT09)

                      * ID: 526 586 1328 / PW: 8804226

A non-zero Electric Dipole Moment (EDM) in a non-degenerate system violates time-reversal (T-)symmetry and consequently also charge-parity (CP-)symmetry. EDM measurements are therefore sensitive searches for new CP-violating interactions. The octupole deformation and nearly degenerate nuclear parity doublet in Ra-225 make it an attractive candidate for probing CP violations within the atomic nucleus. Our latest measurement limits the EDM of Ra-225 to be less than 1.4 × 10^(−23) e cm (95%C.L.), and is the first ever measurement of an EDM limit using laser cooled and trapped atoms. Further experimental upgrades are being implemented to enhance the current EDM sensitivity of Ra-225. This includes more than a factor of three enhancement in the electric field from our electrode upgrade, a STIRAP-based electron shelving for improved state detection efficiency, and an improved atom slowing scheme for enhancing our atom trapping efficiency by two orders of magnitude. With these upgrades in place our EDM sensitivity should increase by about three orders of magnitude and allow us to substantially improve constraints on certain CP-violating processes within the nucleus. This work is supported by the U.S. DOE, Office of Science, Office of Nuclear Physics, under contract DE-AC02-06CH11357 and the Michigan State University.

Host : Prof. Yong-il Shin