Dalitz plot

Modeling of the common representation of the Dalitz plot can be complicated due to its nontrivial shape. One can however introduce such kinematic variables so that Dalitz plot gets a rectangular (or squared) shape: m'(1,2) = \frac{1}{\pi} \arccos\left(2 * \frac{m(1,2)-m(1,2)_{min}}{m(1,2)_{max}-m(1,2)_{min}} -1\right) ; \theta'(1,2) = \frac{1}{\pi} \theta(1,2) ; where m(1,2)  is the invariant mass of particles 1 and 2 in a given decay event; m(1,2)_{max} and m(1,2)_{min}  are its maximal and minimal kinematically allowed values, while \theta(1,2)   is the angle between particles 1 and 3 in the rest frame of particles 1 and 2. This technique is commonly called "Square Dalitz plot" (SDP). ==References==