Copyright 2025 Congzhou M Sha
This is an evolution code for the transversity parton distribution functions encountered in hadronic physics. The associated preprint can be found at https://arxiv.org/abs/2409.00221v2. If you found this work helpful, please cite our preprint, and eventually our published paper!
First, ensure that you have a Python package system installed. We recommend Miniconda https://www.anaconda.com/docs/getting-started/miniconda/install#anaconda-website.
In your terminal, run:
conda create -n NAME -c conda-forge jupyterlab pip -y
conda activate NAME
pip install tparton
NAME is your choice of label for the conda environment you are creating. The above commands only need to be executed once. To use this environment again after a terminal or computer restart, execute conda activate {NAME} again.
To evolve a transversity pdf, run the command python -m tparton m. This uses the Mellin moment by default. To use the energy scale integration method, run the command python -m tparton t. Use python -m tparton m -h or python -m tparton t -h for help.
An example run will look like:
python -m tparton m INPUTPDF.dat 3.1 10.6 --morp plus -o OUTPUTPDF.dat
We are evolving the INPUTPDF.dat from 3.1 to 10.6 GeV2, for the plus type distribution, and with output written to OUTPUTPDF.dat.
To use the Hirai ODE integration method:
from tparton.t_evolution import evolve
To use the Vogelsang Mellin moment method:
from tparton.m_evolution import evolve
Run help(evolve) for a description of the inputs.