# Cut and compute: Quick cascades with multiple amplitudes

## TL;DR

This paper extends a previously proposed method for calculating decay widths in cascade decays to include multiple cascades and interference effects, providing a faster alternative with results matching standard Monte Carlo methods.

## Contribution

The authors develop an extended algorithm for cascade decay calculations that handles multiple cascades and interference, broadening the method's applicability.

## Key findings

- Algorithm shows excellent agreement with Monte Carlo simulations.
- Efficient computation of complex decay chains with interference effects.
- Applicable to both symmetric and asymmetric four-body decays.

## Abstract

In an earlier paper we have proposed a novel method to compute the decay width for a general $1\to n$ cascade decay where the propagators are off-shell and may be of different spins. Here, we extend our algorithm to accommodate those decays that are mediated by more than one such cascades. This generalizes our prescription and widens its applicability. We compute the three- and four-body toy decay chains where identical final states appear through different cascades. Here, we also provide the algorithm to calculate the interference terms. For four-body decays we discuss both symmetric and asymmetric cascades, providing the expressions for the detailed phase space structure in each case. We find that the results obtained with this algorithm have a very impressive agreement with those from standard softwares using a sophisticated Monte Carlo based phase space integration.