Amplitude analysis of B0(s) to K* K*b decays at the LHCb experiment and preparations for future charmless B to VV analyses.

This thesis presents an analysis of data collected by the LHCb experiment, located at the Large Hadron Collider, between 2011—2018. The analysis tests the Standard Model of particle physics, which is known to be incomplete, with decays of unstable B-hadron particles. A significant difference is found between the experimentally measured value and the theoretical prediction, reinforcing earlier experimental results by using new data and several innovative techniques. At the very least, these results will provide crucial input to refine theoretical calculations, and may even hint at new physics beyond the Standard Model.