Scientists have confirmed one of the rarest phenomena of decay in particle physics, found about three times in every billion collisions at the LHCb. They observed a rare transformation of one subatomic particle into anther for the first time.
The way this unfolds casts doubt on versions of the theory of physics known as Supersymmetry (Susy).
It was hoped Susy could explain gaps in the most established theory of how the Universe works. The vast LHC machine, housed in a circular tunnel that runs for 27km beneath the French-Swiss border, smashes beams of protons together at close to light speeds.
Detectors positioned at key points around the underground "ring" are then used to scour the wreckage of these collisions for signs of new particles and physical phenomena.
The theory Susy proposes that each particle has a heavier version of itself which could explain the ever mysterious dark matter, believed to make up a quarter of our Universe.
However, the rate of decay found was predicted by the Standard Model - the framework for particle physics devised in the 1960s and 1970s - even though it's now seen as an incomplete description of nature.
It is not yet able to explain gravity, or indeed the dark matter and dark energy which together make up 95% of the Universe.
Some particles naturally decay into others and the types of decay can help physicists refine key theories. Here scientists found a particle called a Bs meson decaying into two muons for the first time.