The symmetries C （particle-antiparticle interchange） and P （space inversion） hold for strong and electromagnetic interactions. After the discovery of large C and P violation in the weak interactions, it appeared t...The symmetries C （particle-antiparticle interchange） and P （space inversion） hold for strong and electromagnetic interactions. After the discovery of large C and P violation in the weak interactions, it appeared that the product CP was a good symmetry. In 1964 CP violation was observed in K^0 decays at a level given by the parameter e ≈ 2.3 ×10^-3.展开更多
The possible final states for the decay K^0→ π＋π-π^0 have isospinI = 0, 1, 2, and 3. TheI= 0 andI= 2states have CP = ＋1 and Ks can decay into them without violating CP symmetry, but they are expected to be stron...The possible final states for the decay K^0→ π＋π-π^0 have isospinI = 0, 1, 2, and 3. TheI= 0 andI= 2states have CP = ＋1 and Ks can decay into them without violating CP symmetry, but they are expected to be strongly suppressed by centrifugal barrier effects. The I = 1 and I = 3 states, which have no centrifugal barrier, have CP = -1 so that the Ks decay to these requires CP violation.展开更多
文摘The symmetries C （particle-antiparticle interchange） and P （space inversion） hold for strong and electromagnetic interactions. After the discovery of large C and P violation in the weak interactions, it appeared that the product CP was a good symmetry. In 1964 CP violation was observed in K^0 decays at a level given by the parameter e ≈ 2.3 ×10^-3.
文摘The possible final states for the decay K^0→ π＋π-π^0 have isospinI = 0, 1, 2, and 3. TheI= 0 andI= 2states have CP = ＋1 and Ks can decay into them without violating CP symmetry, but they are expected to be strongly suppressed by centrifugal barrier effects. The I = 1 and I = 3 states, which have no centrifugal barrier, have CP = -1 so that the Ks decay to these requires CP violation.
