Grant: Subatomic Physics Envelope - Individual

The major theme of this grant request is the study of emergent structures in nuclei, namely collective excitations, and to investigate their natures using a broad spectrum of probes, including beta-decay, direct reactions, Coulomb excitation, and neutron capture, and to levels of detail that have previously been rarely achieved. The research aims to provide a global view of the data that incorporates both microscopic and collective features, and by pushing beyond the structures that exist in the low-lying part of nuclear level schemes. A second major theme is to investigate nuclei that are used as ``laboratories'' to search for physics beyond the Standard Model, or for completely new physics such as the nature of Dark Matter. Thirdly, this grant request will support the continued development of new instrumentation that serves directly not only the above physics goals, but also as devices available for the the broader research community. My research is performed at the world's leading laboratories, including TRIUMF, Legnaro Nuclear Laboratory (LNL), the Heavy Ion Laboratory (HIL), Argonne National Laboratory (ANL), and the Institute Laue Langevin (ILL) that provide complementary capabilities. Following our suggestion that the Cd isotopes possessed multiple shape coexistence, we have proposed a series of Coulomb excitation experiments at the HIL, LNL, and ANL to provide definitive answers regarding their structure.  We are also performing new measurements using beta-decay at TRIUMF to provide an unprecedented sensitivity to the important, but weak, low-energy decay branches. We are further studying the structure of other nuclei in the Sr to Ru region using facilities at TRIUMF, the ILL, LNL, and HIL to understand the nature of the rapid transition observed in the nuclear properties that occurs at N=60 and test state-of-the-art nuclear theory. I am extending the studies towards the 78Ni region through investigations of the neutron-rich Zn isotopes to understand how their structure evolves. I am pursuing studies on those nuclei important for neutrinoless double beta-decay, especially for 136Xe. We have completed investigations of the pairing properties of 136Ba, and will perform a series of Coulomb excitation measurements to understand its deformation. We are also performing spectroscopic studies of the intermediate nucleus 136Cs that may have important implications for detection of solar neutrinos and also as a Dark Matter detector.  We are developing a new neutron detector, DAEMON, to be coupled with the DESCANT and GRIFFIN spectrometers that will enable precise energy measurements of neutrons emitted following beta-decay. This will bring a major new capability for experiments at TRIUMF. This grant request seeks support for these activities, and the training of my diverse group of 6 graduate students and a number of undergraduate students, as well as support for a Research Associate.