Quantum oscillations of neutral particles with the beauty quark

The development of quantum mechanics since the beginning of the 20th century has guided the exploration of nature at the atomic scale. The analysis of particles produced in cosmic rays and accelerators allowed to study the quantum mechanical behaviour of neutral mesons and gain insights into the fundamental quantum fields governing the interactions of matter. The measurement of wave-like properties, such as oscillation frequencies and interference patterns, is achieved by studying the rate of change of neutral particles into their anti-matter counterpart. This thesis presents the most precise measurement of the oscillation frequency of the $B^0_s$ meson, a neutral state made by the combination of a beauty and a strange quark, using data from the LHCb experiment. Since boson and fermion fields enter virtually in $B^0_s-\overline{B}^0_s$ transitions, the measurement of the $B^0_s$ oscillation frequency does not only offer a laboratory to study the beautiful quantum mechanical properties of the subatomic world, but also provides a gateway to the relativistic quantum fields constituting all elementary particles and fundamental interactions.