Gilbert Hausmann Award - 2023 - Guillaume Pietrzyk

For the development of a new experimental technique that allowed the measurement of the oscillation parameters of an elementary particle into its antiparticle with unprecedented accuracy, and for the exceptional quality of the results of this measurement in the LHCb experiment at CERN.

In 1928, Paul Dirac made a significant breakthrough in modern physics by unifying the theories of quantum mechanics and special relativity. His equations revealed the existence of antimatter, a mirror image of matter with opposite electric charge. Understanding the interaction between matter and antimatter is key to unraveling the mysteries of the Big Bang. The Large Hadron Collider Beauty (LHCb) detector, located at one of the collision points of the LHC, stands as a leading particle physics experiment today. One of its objectives is the exploration of a captivating quantum mechanical phenomenon that allows matter and antimatter particles to oscillate back and forth between one another. Particles known as charm mesons are produced abundantly at the LHCb experiment. They have the special property of exhibiting very slow matter-antimatter oscillations. By developing innovative analysis tools, the measurement of this thesis significantly enhances our understanding of these oscillations, laying the foundation for future advancements in charm measurements.