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Line shape analysis for precision spectroscopy in Ba+ ions

PhD ceremony:N. (Nivedya) Valappol, MSc
When:November 12, 2019
Supervisor:prof. dr. K.H.K.J. (Klaus) Jungmann
Co-supervisor:dr. L. Willmann
Where:Academy building RUG
Faculty:Science and Engineering

The Standard Model (SM) of physics provides a unique and elegant description of fundamental fermionic particles and the  fundamental interactions between them. The SM has been enormously successful in describing and predicting a wide range of phenomena in physics, in particular in particle physics. However, a number of experimental and theoretical reasons are known which strongly point to the fact that the SM is a yet incomplete description of the full set of observations in particle physics. This work paves a way to the search for physics beyond the SM at the precision frontier. We design an experiment to measure the violation of the parity symmetry in atoms ( Atomic Parity Violation, APV) in order to explore the validity of the SM. The weak interactions are the only fundamental interactions that break discrete symmetries among which the parity-symmetry. The strength of the weak interaction at low momentum transfer has been determined in one outstanding experiment with an intense cesium atomic beam, two decades ago. This work is towards a more precise quantitative measurement of APV in a single trapped Radium ion. We employ here a single trapped Barium ion in a radio frequency Paul-trap. It is used as a precursor for a thorough study as it is difficult to anticipate all potential systematic effects. Important atomic properties for measuring APV are the line shapes of atomic transitions, isotope shifts, light shifts, and transition matrix elements.

Among others, this study involves line shape analysis. It has lead to the most accurate values for the transition frequencies in the electronic three-level system of three isotopes of Ba, 138Ba+, 136Ba+, and 134Ba+. This improves the isotope shifts by a factor of 3 to 10 over previous measurements.