$\require{cancel}$ Final (main) Block D, describing $X + s_{134} (\to p_4 + s_{13} (\to \cancel{p_1} p_3)) + s_{256} (\to p_6 + s_{25} (\to \cancel{p_2} p_5))$

This Block addresses the change of variables needed to pass from the standard phase-space parametrisation for $p_{1 \dots 6} \times \delta^4$ to a parametrisation in terms of the four (squared) masses of the intermediate propagators.

The integration is performed over $s_{13}, s_{134}, s_{25}, s_{256}$ with $p_{3 \dots 6}$ as input. Per integration point, the LorentzVector of the invisible particles, $p_1$ and $p_2$, are computed based on the following set of equations:

• $s_{13} = (p_1 + p_3)^2$
• $s_{134} = (p_1 + p_3 + p_4)^2$
• $s_{25} = (p_2 + p_5)^2$
• $s_{256} = (p_2 + p_5 + p_6)^2$
• Conservation of momentum (with $\vec{p}_T^{tot}$ the total transverse momentum of visible particles):
  • $p_{1x} + p_{2x} = - p_{Tx}^{tot}$
  • $p_{1y} + p_{2y} = - p_{Ty}^{tot}$
• $p_1^2 = m_1^2$
• $p_2^2 = m_2^2$

Up to four solutions are possible for $(p_1, p_2)$.

Integration dimension

This module requires 0 phase-space point.

Global parameters

Parameters

Inputs

Outputs

Note

This block has been validated and is safe to use.

See also

Looper module to loop over the solutions of this Block

Definition at line 87 of file BlockD.cc.