2020 Medal Winners | francais

The 2020 CAP-TRIUMF Vogt Medal for Contributions to Subatomic Physics

is awarded to

Gordon C. Ball

"I am truly honoured to be the recipient of the 2020 CAP-TRIUMF Vogt Medal. To be chosen for this award by the Canadian Subatomic Physics community is a very humbling experience. I am especially grateful to all my ISAC-science collaborators with whom I wish to share this recognition." winner citation

The Canadian Association of Physicists (CAP) and TRIUMF are pleased to announce that the 2020 CAP-TRIUMF Vogt Medal for Contributions to Subatomic Physics is awarded to Gordon C. Ball, TRIUMF, in recognition of for fundamental contributions to low-energy tests of the Standard Model through ultra-high precision measurements of superallowed Fermi beta decays and for his leadership in the development of the ISAC science program at TRIUMF. announcement

The Standard Model (SM) has been spectacularly successful in describing the basic building blocks of matter and the forces by which they interact but is generally believed to be only an approximation to a more fundamental theory. Testing the limits of the SM, and searching for the new physics beyond it, involves complementary experiments at the world's highest energy accelerator facilities and high-precision measurements at lower energies. In the latter arena, precise measurements of a special class of nuclear beta decays known as superallowed Fermi transitions have provided the most demanding tests of a number of fundamental tenets of the SM, including the conservation of the vector current of the weak interaction and absence of weak scalar currents, as well as the most precise determination of the leading element of the matrix describing the transformation between the mass and weak interaction eigenstates of the quarks.

Over the past two decades, Gordon C Ball has led a high-impact program of superallowed Fermi beta decay studies that exploits the high-intensity, high-quality beams of rare isotopes provided by the ISAC facility at TRIUMF. He has led the development of experimental techniques that have pushed the precision frontier of the field, his group having set new world records for high precision superallowed beta decay half-life measurements on 4 separate occasions in the past decade. In parallel, he developed new techniques that allowed the determination of superallowed branching ratios for heavy nuclei with an order of magnitude greater precision than previously achieved. These ultra-high precision measurements by Dr. Ball and his collaborators have provided critical tests of the theoretical models required to understand the impact of the breaking of isospin symmetry in the nucleus on the superallowed Fermi beta decay transition rates and, ultimately, on the precise tests of the SM they provide. It is for his outstanding body of work in advancing the field of high-precision superallowed Fermi beta decay measurements that Dr. Ball recognized by the 2020 CAP-TRIUMF Vogt Medal. nominator citation

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