phasespace
phasespace#
Functions for determining phase space boundaries.
See also
- class Kibble(sigma1, sigma2, sigma3, m0, m1, m2, m3, **hints)[source]#
Bases:
UnevaluatedExpression
Kibble function for determining the phase space region.
(1)#\[\begin{split} \begin{array}{rcl} \phi\left(\sigma_{1}, \sigma_{2}\right) &=& \lambda\left(\lambda\left(\sigma_{2}, m_{2}^{2}, m_{0}^{2}\right), \lambda\left(\sigma_{3}, m_{3}^{2}, m_{0}^{2}\right), \lambda\left(\sigma_{1}, m_{1}^{2}, m_{0}^{2}\right)\right) \\ \end{array}\end{split}\]with \(\lambda\) defined by (2).
- class Kallen(x, y, z, **hints)[source]#
Bases:
UnevaluatedExpression
Källén function, used for computing break-up momenta.
(2)#\[\begin{split} \begin{array}{rcl} \lambda\left(x, y, z\right) &=& x^{2} - 2 x y - 2 x z + y^{2} - 2 y z + z^{2} \\ \end{array}\end{split}\]See also
- is_within_phasespace(sigma1, sigma2, m0, m1, m2, m3, outside_value=nan) Piecewise [source]#
Determine whether a set of masses lie within phase space.
(3)#\[\begin{split}\begin{cases} 1 & \text{for}\: \phi\left(\sigma_{1}, \sigma_{2}\right) \leq 0 \\\text{NaN} & \text{otherwise} \end{cases}\end{split}\]with \(\phi\) defined by (1).