Physicists Observe Violation of CP-Symmetry in Experiments on the Great Adron Collider
Physicists from the European Center for Nuclear Research (CERN) have published new results from their experiments on the Great Adron Collider (LHC). These results include measurements of the violation of symmetry between matter and antimatter in particles with severe quarks. This violation is known as a violation of CP-symmetry, which may explain the predominance of matter over antimatter in the universe.
The principle of CP symmetry suggests that the laws of physics remain unchanged while changing the charge of a particle to its opposite and its reflection in the mirror. However, experiments conducted in 1964 have shown that CP-symmetry is disturbed in the decays of neutral casons, particles that consist of quarks s and d. Further research established violations of CP-symmetry in the decay of neutral B-Mesons, particles containing quarks B and D or B and S.
The physicists used two detectors, LHCB and CMS, to study the decay of B-Mesons with high accuracy. In their new work, they combined data from both detectors to arrive at the most precise measurement of the parameter characterizing the violation of CP-symmetry in the decays of B-Mesons for a pair of J/ψ and KS. This parameter, known as Sψks, equals the sinus of the angle of the phase of decay. If CP-symmetry is not violated, then Sψks should be zero.
The physicists found that Sψks is different from zero at a statistically significant level of 5 sigma, corresponding to a deviation from the zero hypothesis in less than one case out of 3.5 million. They obtained a value of Sψks, which is equal to 0.731 ± 0.035, consistent with the predictions of the standard model—the theory describing all the well-known elementary particles and their interaction.
The measurement is one of the most precise in the field of physics of heavy quarks and illustrates the high sensitivity of LHC detectors to violations of CP-symmetry. However, the standard model cannot fully explain the asymmetry between matter and antimatter. Hence, physicists continue their search for new physical phenomena, which can lead to greater violations of CP-symmetry predicted in the standard model.