Current theories and experimental evidence suggest that the universe started as a massive fireball of pure energy which condensed into matter as the universe expanded and cooled. But when energy turns into matter it creates an equal and opposite amount of antimatter.... which leads us to the perplexing question:
Andrei Sakharov proposed three necessary conditions to account for the predominance of matter over antimatter:
LHCb's primary concern is the second of these: CP violation where C stand for charge and P for parity. CP symmetry implies that your world looks the same if you flip the charge on everything and view the process in a mirror. I've tried to demonstrate this on the right
using an Escher print. Starting with your world in the top left corner you can either reflect it in a mirror (P) or swap the colours (C). If you do both (CP) you end up with the original situation.
But Sakharov says that if the original view and the CP view were EXACTLY the same, we couldn't exist; the perfect symmetry would allow matter and anti-matter to annihilate. So we must have a small amount of CP violation, and if you look carefully at the Escher print manipulated in this way, the symmetry isn't in fact perfect.
The LHCb experiment will investigate CP violation using b quarks. Because these are light, they are produced in the forward direction at the LHC. The LHCb experiment consequently is offset to one side of the collision point in order to capture the flying B mesons.
The protons interact inside the detector marked Vertex and the decay particles leave traces in the sub-detectors. The vertex and tracker measure the position accurately. The calorimeters measure the energy. The RICHs lets you distinguish protons, kaons, pions and electrons. The muon chambers record penetrating muons. A magnet bends the particles allowing their momentum to be determined.
Apart from studying CP violation, LHCb can also make precision electroweak measurements.
A cornerstone of the Standard Model of Particle Physics that received the Nobel Prize in
1979,
1984 and
2004, is the force carriers for the electroweak interaction, the W and Z bosons.
By studying the production of Z,W+ and W- bosons at the LHC, we can test the predictions
of the Standard Model to better than 1%. In doing so, we can also examine the sub-structure
of the proton and view the quarks and gluons bound within. It is this physics that we at UCD are particularly interested in investigating.