Rüdiger Picker

Why is matter dominating over antimatter in the universe? Which beyond the standard model (BSM) theory can hold? How were the first elements formed? Are there only three quark families?

These are all questions that fundamental physics experiments with slow neutrons can contribute to, and Dr. Picker’s research has been focused on them for more than two decades.

At TRIUMF, in the TUCAN collaboration, Picker and his team are tackling the first two questions by building and conducting an experiment to search for the electric dipole moment of the neutron (nEDM). If found, it would signify CP violation, an important ingredient in baryogenesis that could explain the matter-antimatter asymmetry. If the current limit on the nEDM is reduced, this challenges several BSM theories.

The last two questions are connected to the lifetime of the free neutron. It influences Big Bang nucleosynthesis models; especially, the helium abundance in the universe is sensitive to it. The neutron lifetime is also an important ingredient of unitarity tests of the CKM quark mixing matrix. If non-unitary, our understanding of the particle physics with its three quark generations would be shattered. The TUCAN collaboration is aiming to improve the precision of the neutron lifetime using PENeLOPE, a precision experiment on the neutron lifetime operating with proton extraction.

PENeLOPE and the TUCAN EDM both require a large number of ultracold neutrons (UCN), and the teams are building such a source at TRIUMF.

Interested students and postdoctoral fellows are encouraged to reach out!