2016-2017 Rosen Scholar
- LANSCE User Office
- Mail Stop: H805
- (505) 667-6797
Dr. Chen-Yu Liu is an Associate Professor of Physics at Indiana University at Bloomington. Her research focus is on symmetry tests and fundamental neutron physics; in particular, she specializes in techniques with ultracold neutrons (UCN). These neutrons, due to their very low kinetic energies, can be stored in material bottles or magnetic traps for durations of up to hundreds of seconds. The long storage time allows for measurements of many fundamental properties of this charge- neutral hadronic system, with improved precision. Using UCN as the principle tool (but not limited to it), Prof. Liu’s research group has been developing experimental techniques to measure the neutron beta- decay lifetime, the neutron decay asymmetries, and the electric dipole moment of the neutron with the aim to reduce experimental uncertainties to a level sufficient to challenge the predictions of the electroweak theory and, by scrutinizing the low-energy neutron observables, to search for long-awaited evidence of physics beyond the Standard Model of particle physics.
Since 2011, Prof. Liu has been a co-spokesperson of the UCNtau experiment, an effort to improve the measurement of the neutron beta-decay lifetime using UCN in a magneto-gravitational trap. This experiment uses UCN from the LANSCE source. This effort was motivated by a discrepancy among the recent precision measurements of the neutron lifetime; the separate averages of two independent methods (the beam and bottle techniques) lead to neutron lifetimes that differ by as much as ten seconds, while the uncertainties reported from individual experiments are on the level of two seconds (in the beam experiment) and one second (in the bottle experiments). Resolving this discrepancy and improving the precision of the neutron lifetime will not only refine the physics of electroweak decay but also impact the model of Big Bang Nucleosynthesis.
Prof. Liu was a Sloan Research Fellow in 2007-2008; She is the recipient of the 2015 NIST Precision Measurement Grant and National Science Foundation awards. She is currently serving on the American Physical Society Division of Nuclear Physics Program Committee and the LANSCE User Executive Committee.