A solution to the puzzle of quenched beta-decays and a quantum computation of an atomic nucleus

Gaute Hagen (Oak Ridge National Laboratory)
Event Date and Time: 
Thu, 2018-03-01 14:00 - 15:00
TRIUMF Auditorium

For over 50 years, a central puzzle has been that observed beta decay rates are systematically smaller than theoretical predictions. This was attributed to an apparent quenching of the fundamental coupling constant gA in the nucleus by a factor of about 0.75 compared to the beta decay of a free neutron. The origin of this quenching is controversial and has so far eluded a first-principles theoretical understanding. This talk presents a solution to this puzzle, and shows that this quenching arises from two-body currents and strong correlations. I will present state-of-the-art computations of beta decays from light to heavy nuclei, and the results are consistent with experimental data, including the pioneering measurement for 100Sn. These theoretical advances are enabled by systematic effective field theories of the strong and weak interactions combined with powerful quantum many-body techniques.

In the second part of this talk I will present a quantum simulation of the deuteron binding energy on quantum processors accessed via cloud servers. We computed the binding energy to within a few percent by designing a low-depth version of the unitary coupled-cluster ansatz, and using the variational quantum eigensolver algorithm. Our work is the first step towards scalable nuclear structure computations on a quantum processor via the cloud, and it sheds light on how to map scientific computing applications onto nascent quantum devices.

Website development by Checkmark Media. Designed by Armada.

a place of mind, The University of British Columbia

Faculty of Science
Department of Physics and Astronomy
6224 Agricultural Road
Vancouver, BC V6T 1Z1
Tel 604.822.3853
Fax 604.822.5324

Emergency Procedures | Accessibility | Contact UBC | © Copyright The University of British Columbia