Dalitz chart

The Dalitz plot is a graphical representation of the results used in particle physics to analyze particle decays into three other particles. Richard Dalitz introduced this diagram in 1953 when considering the decays of K-mesons .

The kinematics of three-particle decays can be completely described using only two variables. Traditionally, the Dalitz diagram is a two-dimensional diagram, along whose axes the mass of two different pairs of particles from the decay is deposited. For example, if a certain particle A breaks up into three particles 1, 2 and 3, then the Dalitz diagram for this decay is a two-dimensional histogram, where along the X axis is laid out ₁₂ m², and along the Y axis - m² ₂₃ . If the decay is indeed a true three-particle decay, then the distribution of events on the Dalitz diagram should be uniform. However, usually three-particle decays occur with the participation of resonances, that is, the particle decays into a resonance and the particle being recorded, and the resonance in turn splits into two other particles. In this case, the distribution of events on the Dalitz diagram assumes a substantially inhomogeneous structure with an increased concentration of events in the region of invariant masses coinciding with the mass of resonances. The Dalitz diagram is a convenient tool for studying the dynamics of three-particle decays. This technique can be adapted for the study of four-particle decays.