Breaking a collision into pieces

The ultimate goal of physics is decifering the laws that describe nature from our observations. Centuries of research has led to the conclusion that the matter and forces in our world consist of and are driven by elementary particles, as described by the Standard Model of particle physics. This model, however, does not describe the universe perfectly and is known to be incomplete. In order to test our knowledge and find precisely where the theory breaks down, predictions from the Standard Model are compared to results from particle collider experiments, such as the Large Hadron Collider. Years of research, however, has found little to no deviations from the Standard Model and higher theoretical and experimental precision is necessary. This is not easy, as making theoretical predictions for collider experiments is notoriously hard. In this thesis I study Soft-Collinear Effective Theory (SCET), a method that allows one to break a collision up into universal and/or calculable pieces, and apply it to collider observables in order to obtain high-precision theoretical predictions. These results are ready to use in fits to experimental data to constrain theory parameters and perform precision tests the Standard Model. Moreover, the methods developed in this thesis are applicable beyond the observables in this thesis, enabling precise theoretical predictions for a wide range of collider observables.