The paper discusses the importance of Wigner rotations in the helicity formalism for modeling cascade reactions, which are essential for studying hadronic resonances.
The key highlights are:
Cascade parameterization models the dynamics of a multi-body decay as a sum of coherent processes, each representing sequential decays with intermediate resonances. Wigner rotations are required to ensure consistent treatment of spin quantization axes across different decay chains.
The authors provide a general algorithm for computing Wigner rotations, including handling the 2π discontinuities that arise due to the definition of kinematic variables. These discontinuities can lead to sudden sign changes in the decay-chain amplitudes, which need to be compensated by the Wigner rotations.
The paper also discusses the impact of particle ordering on the spin-orbit couplings and Wigner rotations, and demonstrates the mathematical equivalence between the helicity, minus-phi, and canonical conventions for amplitude formulations.
The authors provide a publicly available numerical routine for computing Wigner rotations, which can be useful for amplitude analyses in hadron spectroscopy.
To Another Language
from source content
arxiv.org
Key Insights Distilled From
by Kai Haberman... at arxiv.org 10-01-2024
https://arxiv.org/pdf/2409.06913.pdfDeeper Inquiries