How to do a data theory comparison

This tutorial explains how to compare the data and theory for a given data set or list of data sets.

You need to provide:

  1. A PDF which includes your data set;

  2. A valid theory ID;

  3. A choice of cuts policy;

  4. A list of data sets to do the comparison for.

Below is an example runcard for a data theory comparison for BCDMSP, runcard.yaml:

meta:
    title: BCDMSP data/theory comparison
    keywords: [example]
    author: Rosalyn Pearson

pdfs:
    - id: NNPDF31_nnlo_as_0118
      label: NNPDF31_nnlo_as_0118

theoryid: 53

use_cuts: false

dataset_inputs:
      - { dataset: BCDMSP}

template: dthcomparison.md

actions_:
  - report(main=true)

The corresponding template, dthcomparison.md, looks like this:

%BCDMSP (theory ID 52)

{@ dataset_inputs plot_fancy @}
{@ dataset_inputs::pdfs plot_fancy(normalize_to=data)@}
{@ dataset_inputs::pdfs plot_chi2dist @}
{@ dataset_inputs::pdfs group_result_table @}

  1. plot_fancy produces data-theory comparison plots for the data. This is called twice to produce both normalised and unnormalised sets of plots.

  2. plot_chi2dist gives the chi2 distribution between the theory and data.

  3. group_result_table gives the numerical values which appear in the plots.

Running validphys runcard.yaml should produce a validphys report of the data-theory comparison like the one here - see the vp-guide.