Swiss Grant Bolsters VU and Nikhef Research on Asymmetry Between Matter and Antimatter

Wouter Hulsbergen, distinguished professor of Flavor Physics at the LHC at VU Amsterdam and a researcher at Nikhef, is a co-applicant for the grant. EPFL is the Swiss Federal Institute of Technology in Lausanne, Switzerland. Laurent Dufour, a former Nikhef Ph.D. candidate, is the principal investigator for the grant at EPFL.

According to the Standard Model, the leading theory in particle physics, matter and antimatter should have been created in nearly equal amounts after the Big Bang. Yet the observable universe consists almost entirely of matter. The small differences between matter and antimatter described by the Standard Model cannot fully explain this imbalance.

The project seeks evidence of physics beyond the Standard Model through precise measurements of neutral B mesons. These particles exhibit quantum behavior that makes it possible to study extremely small differences between matter and antimatter, also known as CP violation.

The researchers will use the complete dataset from Run 3 of the LHCb experiment at CERN. They will combine measurements of various B-meson decays to determine a key parameter in the Standard Model: the CKM angle beta. The goal is to improve the precision of this measurement by a factor of two to three.

Such measurements can reveal effects of new particles or interactions, including particles that are too heavy to be produced directly in the Large Hadron Collider. Comparing different decay processes is essential at this level of precision, as subtle effects must be understood and controlled.

The grant is awarded by the Swiss National Science Foundation (SNSF) and will fund a Ph.D. student and a postdoctoral researcher for the local LHCb group. The Ph.D. student is expected to spend a year at EPFL or at CERN, further strengthening the collaboration between the Swiss and Dutch teams.

The research will also contribute to the calibration and understanding of LHCb’s new scintillating-fiber tracking detector. Better characterization of the detector improves the reliability of simulations and measurements, which benefits both this project and other LHCb investigations into new physics.