CPtransformed

CPtransformed is the designation for the state, field, or observable obtained after applying the CP transformation to a quantity in particle physics and related fields. The CP transformation combines charge conjugation (C), which exchanges particles with their antiparticles, and parity inversion (P), which reverses spatial coordinates. In quantum theory, applying CP to a field or state yields its CP-transformed partner, often denoted with a CP superscript or by explicitly constructing the CP-conjugate object.

In field theory, CP acts on fields by mapping a given field configuration to its CP-conjugate configuration with spatial coordinates inverted. For example, a scalar field may transform to a CP-transformed field evaluated at (-t, -x), with possible phase factors depending on the field’s intrinsic properties. For fermions and other spinful fields, the transformation also involves spinor structure and charge conjugation, producing the CP-transformed spinor or operator. The CP-transformed state |ψ_CP⟩ is the result of applying the CP operator to the original state |ψ⟩.

CPtransformed quantities are central to the study of CP violation. If a process or state is invariant under CP, it is possible to relate amplitudes and decay rates of a quantity to those of its CP-transformed counterpart. In practice, comparisons between a decay amplitude A_f and its CP-conjugate amplitude Ā_f provide measures of CP violation through asymmetry parameters. The concept is especially important in neutral meson systems, such as kaons and B mesons, where CP eigenstates emerge and CP-violating effects are experimentally observable.

CPtransformed objects also aid in theoretical analyses of symmetries, model-building, and the interpretation of experimental results across particle physics and related disciplines.