Recently, the LHCb collaboration has computed the aligned polarimeter vector field for the dominant hadronic decay mode of the $\Lambda_c$ baryon (arXiv:2301.07010). The polarimeter vector field is a model-independent representation of the decay rate for polarized decays that can be used to measure polarisation and to improve the sensitivity of amplitude models.
The computations were performed with a new approach using methods from the ComPWA project. Amplitude models are implemented symbolically with a Computer Algebra System, so that the mathematics can be easily inspected. The symbolic model then serves as a template for fast, numerical back-ends like JAX and TensorFlow. This symbolic approach makes it easy to formulate and fit amplitude models in a self-documenting workflow with high performance on large, multidimensional data samples. In addition, the approach proved flexible enough to compute these more complicated polarimeter vector fields.