The quest to understand why our Universe is made of matter rather than antimatter has received a boost at the Large Hadron Collider. The LHCb experiment has for the first time observed decays of particles known as Bs mesons that preferentially end up as matter, rather than antimatter.
However, the difference is still not enough to explain the preponderance of matter over antimatter in the cosmos. The work, published online, has been submitted to Physical Review Letters.
Every member of the zoo of particles we know about has an antimatter cousin, identical in every way except for an opposite electric charge - the electrons and protons that in part make us up have positrons and antiprotons as their antimatter matches.
The current theory for how the Universe got its start holds that equal amounts of matter and antimatter were initially created. But whenever the two meet, they destroy each other in a flash of light.
Simply put, the Universe should have come to a blazing end just then. Something must have made for a slight excess of matter in order to lead to the matter-dominated Universe we see today.
It is the subtle details of this preference for matter that the LHCb experiment is hunting for as it tracks particles created when protons are smashed together.
Just like the long-running hint for the particle called the Higgs boson, clues arise in the showers of particles created by these violent collisions.