The LHCb experiment’s enormous magnet consists of two coils, both weighing 27 tonnes, mounted inside a 1,450 tonne steel frame. A new study reports that scientists have observed the decays of a rare particle that was present right after the Big Bang for the first time.
Credit: CERN
SHROPSHIRE: Using data from the Large Hadron Collider (LHC) experiment, a team of scientists has observed new behaviour of an exotic ‘B meson’ particle. The discovery of this new particle decay mode could help to shed light on one of the most puzzling unknowns in physics.
When the universe was formed from the Big Bang 14 billion years ago, matter and antimatter were created in equal quantities. Today, however, we find ourselves in a universe composed almost entirely of matter. The apparent disappearance of antimatter could be explained if scientists discover differences in the way matter and antimatter decay.
“[The result] tells us about the structure of these decays and allows us to compare with theoretical models,” said lead author Sheldon Stone from Syracuse University in New York. “Any difference would be a matter/antimatter asymmetry…which has great implications for the presence of physics beyond what we currently understand, something we call ‘New Physics’.”
Where did all the antimatter go?
Current understanding of particle physics is centred on the ‘Standard Model’ in which the neutrons and protons that make up an atom are composed of even smaller particles, known as ‘quarks’.
Each particle has a corresponding ‘antiparticle’ with the same mass and opposite electric charge. We know that the Big Bang created matter and antimatter in equal amounts, so what happened to all the antimatter?
The key to solving this problem may lie in observing B mesons: rare and heavy particles composed of a quark and an antiquark which were common after the Big Bang but are only observable today using high-energy particle colliders such as the LHC.
Proving a prediction
Stone and his colleagues have measured a particular decay of the B meson for the first time. By investigating the nature of the forces that influence such a decay, scientists hope to understand why antimatter all but disappeared after the Big Bang.
This decay mode was found using CERN’s LHCb particle detector (Large Hadron Collider beauty experiment, where 'beauty' refers to the bottom quark), located deep beneath the French countryside. Two proton beams were accelerated close to the speed of light, giving rise to as many as 10 million proton collisions every second. Careful analysis of the resulting data led to the new discovery, published in the journal Physics Letters B.
Matter-antimatter asymmetry
In the symmetric Einstein spacetime, lifetime of each particle and its antiparticle is the same. The Everlasting Theory shows that symmetry of the Einstein spacetime was broken after the period of inflation but before the soft big bang. The Einstein spacetime, in its ground state, consists of the non-rotating binary systems of neutrinos. Inside our Universe, there is more the electron-antineutrinos than the other neutrinos. This caused that our Universe consists of the matter. It is not true that there is a matter-antimatter asymmetry. The observed asymmetry is due to the local asymmetry of the Einstein spacetime.
Sylwester Kornowski