RTU Researcher Viesturs Veckalns explaining the processes in a particle accelerator experiment during CERN Science Week in Latvia, 22.–26.05.2017.
Photo: Riga Technical University
High energy physics is a branch of physics studying highly excited states of matter and probing matter on the subatomic scale. Nowadays the most fundamental questions in this field are the evolution of our Universe and understanding what it is composed of (95% of it is the so called dark matter and dark energy). For the instrumentation, scientists in this field use giant particle accelerators to study particles that have been naturally accelerated in space.
RTU participates in the CMS top quark physics group undertaking a study of colour flow in top quark pair decays. Our scientist Viesturs Veckalns, author at CMS, works there.
The top quark t decays in the weak process emitting a bottom quark b and the weak boson W. The weak boson can decay emitting two colour-connected light quarks q1 and q2. The colour field quickly evaporates forming a number of particles that we can observe with the CMS detector.
The CMS detector is particularly suited for this kind of study given the 4T magnetic field in the superconducting solenoid and the state-of-the-art silicon pixel detector. We then use appropriate observables to confirm and study colour connection between two quarks.