{"id":26,"date":"2015-05-26T19:30:00","date_gmt":"2015-05-26T19:30:00","guid":{"rendered":"https:\/\/budker.uni-mainz.de\/?page_id=26"},"modified":"2022-12-12T13:27:47","modified_gmt":"2022-12-12T13:27:47","slug":"dysprosium-experiments","status":"publish","type":"page","link":"https:\/\/budker.uni-mainz.de\/?page_id=26","title":{"rendered":"Dysprosium experiments"},"content":{"rendered":"

The element of success<\/strong><\/p>\n

Atomic Dysprosium $(Z=66)$ has a ground-state configuration of $4f^{10} 6s^2$   and a total electronic angular momentum of $J=8$. Dysprosium is remarkable in that it contains a pair of nearly degenerate, opposite-parity levels, with $J=10$ which lie at an energy of $19798\\, \\text{cm}^{-1}$  above the ground state. In addition, Dy has seven stables isotopes at atomic masses of $A=156,\\,158$ and $A=160-164$, whereas $\\,^{161} Dy$ and $\\,^{163} Dy$ have nonzero nuclear spin of $I=\\frac{5}{2}$. The energy splitting between these states varies with isotope and ranges from a few MHz up to a few GHz.<\/p>\n

Variation of fundamental constants<\/strong><\/p>\n

The pair of near-degenerate, opposite-parity states, is highly sensitive to variation of the fine-structure constant $\\alpha$, due to large relativistic corrections of opposite sign for the opposite-parity levels. In this unique system, in contrast to atomic-clock comparisons which require optical frequency combs to compare energy levels in different atoms, the difference of the electronic energies of the opposite-parity levels can be monitored directly utilizing a radio-frequency (rf), electric-dipole transition between them. The precision spectroscopy of this energy difference over a period time (for example for a year) can be used to constrain both a temporal variation as well-as a gravitational-potential dependence of <\/strong>$\\alpha$ <\/strong>since, during the data-acquisition period, the Earth is located at different values of the gravitational potential of the Sun.<\/p>\n

Parity violation in atomic dysprosium<\/strong><\/p>\n

The high mass of dyspropsium and the small energy seperation between the opposite-parity states will lead to enhancement of weak mixing effects, making thus $Dy$ a promising system for the study of parity non-conservation. Furthermore, the availability of isotopes with nuclear spin allow for the possibility of measuring the anapole moment.<\/p>\n

References<\/strong><\/h4>\n

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