|Illustration showing a proton (red) confined by magnetic-field lines (green) running down the centre of a Penning trap (yellow). (Courtesy: G Schneider, University of Mainz)|
The most precise measurement ever of the proton's magnetic moment has been made by an international group of physicists. The new result – combined with a similar measurement planned for the proton's doppelganger, the antiproton – could help explain one of the deepest mysteries of physics – why the universe's matter seems to vastly outweigh its antimatter.
Every fundamental particle has a nearly identical antiparticle with opposite electric charge. Physicists' leading theories indicate that particles and their antiparticles were created in equal amounts during the Big Bang and should have annihilated each other long ago. But the universe is full of matter and lacks antimatter, suggesting that an undetected difference might exist between the two.
Physics World: Physicists lock in on proton's magnetic moment, Gabriel Popkin