Thanks to the Large Hadron Collider For the first time, physicists were able to record the simultaneous appearance of a photon and a quark (high quark, true quark). Scientists hope so Thanks to this, they will better understand the weak electrical interactions and their relationship with the Higgs field.
According to the Standard Model, elementary particles gain mass as a result of interacting with the Higgs field, and this whole process is controlled by a mechanism called symmetry breaking of electroweak interactions. The hypothesis that was proposed in the 1960s was confirmed in 2012 when the Higgs boson was discovered. However, years have passed and scientists still do not understand the mechanism by which particles break symmetry and gain mass.
Scientists are working on the ATLAS experiment They decided to take a look The mechanism of symmetry breaking and electroweak interactions, and analysis of data on the top quark that appears as a result of the collision of protons. They targeted the T-quark because it interacts strongly with the Higgs field, making it the most massive elementary particle.
Scientists want to monitor the decay of individual t-quarks, take into account deviations from Standard Model predictions, and study symmetry breaking in electroweak interactions. The problem is that individual T quarks are very difficult to observe. Pairs of t-quarks are much easier to observe, but they are controlled by the strong force. Therefore, they decided to look for other pairs – a single quark with a photon interacting with it.
The t quark decays very quickly. Its decay products are the b quark and the W boson. The b quark combines with other quarks to form new hadrons, which then decay into a stream of particles called a “b jet.” Meanwhile, the W boson decays into an electron or muon and a neutrino. Scientists created virtual simulations of T-quark and photon pairs, and based on them, they taught their algorithm to search data obtained from the ATLAS experiment for information about the simultaneous appearance of a gamma-ray photon, jet, electron or muon and the missing energy associated with the presence of a neutrino, which does not ATLAS can detect them. Once their algorithm was trained, they gave it real data to analyze. The results exceeded their wildest expectations. The algorithm detected the required data with a confidence level of 9.3 sigma. Meanwhile, from 5 sigma there is talk of a discovery. This 9.3 sigma means that it is unlikely that the discovered data occurred by chance.
Now scientists will want to take a closer look at photon-quark pairs, and hope it will help them decipher symmetry breaking in electroweak interactions. This would be an important step towards understanding the nature of the Higgs boson and the mechanism by which particles gain mass.
