If it rotated any faster, the riders would quickly become ill. By way of comparison: a fairground swing ride takes five to ten seconds for a single rotation. The magnetic field forces the particles to rotate around 30 million times per second. In order to weigh the proton and antiproton to such a high level of precision, the researchers came up with a clever method: They capture the charged particles in a Penning trap, in which the particles are confined by electrical and magnetic fields. We therefore have to exploit every possibility to check the models as precisely as possible.” “But nature is always good for surprises,” says Klaus Blaum, Director of the Max Planck Institute for Nuclear Physics in Heidelberg and one of the BASE partners. Had the researchers found a difference in mass, it would have called the Standard Model into question, as well as casting doubt on even more fundamental theories of particle physics. The results confirm theories which state that no differences in mass exist between matter and antimatter. “We’ve found that the ratio of charge to mass is identical to one part in 69 trillion,” says Stefan Ulmer, scientist at CERN and spokesperson for the BASE project. In doing so, they compared matter and antimatter in the system to a precision four times greater than was previously possible. Essentially, they weighed the two particles. In their search for infinitesimal differences between matter and antimatter, the BASE researchers measured the charge-to-mass ratio of the proton and antiproton. © Fabienne Marcastel, Georg Schneider / BASE-Collaboration Baryons and antibaryons are subatomic particles which – like protons and antiprotons – consist of three elementary particles namely quarks and antiquarks. That is the purpose of the BASE project, short for Baryon Antibaryon Symmetry Experiment. To this effect, they are looking for detailed experimental evidence of weak points, for example differences between matter and antimatter. Physicists thus want to shore up the theoretical edifice of the Standard Model or even reformulate it to redress its deficiencies. Yet there is still an abundance of matter in the universe. For example, the Standard Model does not explain the asymmetry between matter and antimatter: Although matter and antimatter were created in equal amounts at the beginning of the universe, they subsequently annihilated each other for the most part – a phenomenon that occurs whenever matter meets antimatter. While the Standard Model of particle physics can explain the existence of all known elementary particles and many of their interactions, some observations simply don’t fit the theory.

However, they are unable to currently remedy the shortcomings. Particle physicists are well aware that their worldview is still imperfect.

Antimatter be generated