**This seminar will be conducted remotely via Zoom**
Harikrishnan Ramani, UC Berkeley
Title: Nuclear Isomers as Dark Matter accelerators.
Abstract: Weak-scale dark matter particles, in collisions with nuclei, can mediate transitions between different nuclear energy levels. In particular, owing to sizable momentum exchange, dark matter can enable de-excitation of metastable nuclear isomers trapped in a higher excited state due to angular momentum selection rules. As a result, this detection concept is exothermic in nature and is especially useful for detecting dark matter that would go undetected in traditional direct detection experiments owing to the requirement of energy transfer from detector to dark matter. I will present two example models, dark matter that interacts strongly with nuclei and inelastic dark matter. I will also talk about examples of nuclear isomers that are especially suited for detection in each case. I will also present results from reinterpreting limits on the lifetime of 180m Tantalum which close important gaps in the dark matter direct detection parameter space.