The W boson is the mediator particle of the electroweak force. Discovered in the 1980s at CERN, its properties remain challenging to measure within the Standard Model of particle physics. An international team has now presented a new and improved W-boson mass measurement by the ATLAS experiment at CERN. Physicists from the University of Bonn were involved in the results: Dr. Philipp König and Dr. Oleh Kivernyk are part of the ATLAS team, which has now presented the results at the Moriond electroweak conference. The two young scientists work in the research groups led by Prof. Dr. Klaus Desch and Priv.-Doz. Philip Bechtle and Prof. Dr. Ian Brock at the Physics Institute.

Neutrinos are among the most abundant particles in the cosmos, but still pose many mysteries to researchers. An international team with participation of the University of Bonn has now for the first time directly observed neutrinos produced in a particle accelerator. The physicists hope that their new discovery will enable them to better understand the nature of these almost massless elementary particles. The results were presented last weekend at the 57th Moriond Conference in Italy and will soon be submitted for scientific peer review in the journal Physical Review Letters.

Physicists at the University of Bonn have experimentally proven that an important theorem of statistical physics applies to so-called "Bose-Einstein condensates." Their results now make it possible to measure certain properties of the quantum “superparticles” and deduce system characteristics that would otherwise be difficult to observe. The study has now been published in Physical Review Letters.

An international team of astrophysicists has made a puzzling discovery while analyzing certain star clusters. The University of Bonn played a major role in the study. The finding challenges Newton's laws of gravity, the researchers write in their publication. Instead, the observations are consistent with the predictions of an alternative theory of gravity. However, this is controversial among experts. The results have now been published in the Monthly Notices of the Royal Astronomical Society.