****************  NCTS/CTC/NTHU HEP Seminar ****************

Speaker: Dr. Yasuhiro YAMAMOTO (NCTS)
Title: New force search with precision isotope shift.
Time: 12:30-13:30, Thursday, 2022/11/17
Place : R019, Physics Building, Nat'l Tsing Hua Univ.
Host : Prof. Po-Yen Tseng (NTHU)

Abstract:
The atomic spectrum is affected by the differences in the nuclear state among isotopes.
This spectrum change is called the isotope shift. It is known and tested well that the isotope shifts for two distinct follow a linear relation so called the King linearity. Recently, it has been proposed that the violation of the linear relation can be a good probe of the weakly interacting light boson. In the last year, such a linearity violation was reported. However, the result conflicts with other experimental constraints if the violation is attributed to the new force. Therefore, it should originate from the higher order effects of the Standard Model. While new and precise results are rapidly obtained by experiments, the numerical progress to understand the observed violation is quite poor. We proposed a method to eliminate the higher order isotope shifts with the generalization of the King linearity. In collaboration with the quantum optics group at Kyoto University, we applied this method to the observed non linearity in the King relation with their new measurement of the isotope shift using neutral Ytterbium. Finally, we obtained the new experimental bound to the weakly interacting light boson.
I will also introduce some recent progress on this topic.
This talk is based on 1710.11443, 1911.05345, and 2110.13544.

Online link: https://cern.zoom.us/j/68742084566?pwd=dHRxaTB3RThGc2dMaDA1dDhJOHdXQT09

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If you will attend the seminar and would like to have a lunchbox on that day, please register for it online by 10:00AM  Nov. 16th (Wednesday morning). Late registration will not be accepted.
Link for the online registration: https://forms.gle/Us1ZaDdWDai5z6Wr5
*Note:
1. The lunchboxes will only be prepared for the participation of professors and postdoctoral researchers. Please sign up for your attendance and receive your lunchbox at the lobby of NCTS on 5F between 11:40AM - 12:00PM on Nov. 17th.
2. In order to prevent the potential spread of COVID-19, we suggest that you bring your own face mask and wear it while attending the seminar.