EWP-BplusToKstMuMu-AngAna/Code/Scripts/Python Scripts

Angular Analysis of B+toK*+Pi0Mu-Mu+

Setup

For this setup you will need to install miniconda on the machine you are working and do the following procedure:

1. conda env create -f requirements.yaml
2. Check with conda activate angularanalysis if the environment is working
3. Check out the following page in order to install the analysis-tool package: https://github.com/jonas-eschle/analysis-tools
4. Check out the following page in order to install the angular-analysis B->K*ll package: https://gitlab.cern.ch/LHCb-RD/ewp-bd2ksteeangular-legacy/-/tree/master/b2kstll

Afterwards you can use your conda environment in order to run the code. But before you do, you need to setup the properties.env. Inside of properties.env you will find different configuration variables which are used throughout the code in order to control the behavior of the code. Below you can find a table which summarizes what these environment variables do.

Environment Variable	Use-Case
LOWER_COSTHETAK_CUT	Controls the lower boundary of cos(theta_K)
UPPER_COSTHETAK_CUT	Controls the upper boundary of cos(theta_K)
SYS_PATH	We need one local package in order to make the code work, namely hep_analytics which you can also find in this repo, the interpreter needs to find that package, so set SYS_PATH to the relative path to hep_analytics
GEN_FILE	Path to the Generator File
MC_FILE	Path to the MC File
MC_PHSP_FILE	Path to the PHSP MC File

If you want to see how to set the environment variables, have a look at properties.env. Also, I have run the code on the LHCbA1 machine but it should make no difference where you run the code. You are done (apply also the custom fixes described down below)!

Custom Fix

The b2kstll package has a few caveats when you want to apply a cos(theta_K) cut since the normalisation will be wrong in this case for the pdfs. So in order to compensate for that, I changed a few lines in the packages code, have a look at the b2kstll/models folder, there you will find all the files which I touched.

Useful Scripts

root_file_inspect.py

This script can be used to look inside a root file and see which branches and features it includes. To kick it off, give it a try with:

1. python root_file_inspect.py --file=ROOT_FILE_PATH --regex=.*

You do not need to set the regex flag but it can be useful if you search for some particular feature. This script depends on the file rootio.py.

diff_pair_tables_*.py

There are 3 scripts which are prefixed with diff_pair_tables and which are very similar but have different use-cases. You can use them as templates whenever you have generated tables by prettytable or another library/tool and use them in order to automatically extract the values out of these tables. Then you do not have to type them manually into your code.

hep_analytics

package: pathing

The module aggregate.py exposes the PathAggregator which is very simple and simply builds a path string. For only this reason the class is not very useful but when your directory path setup is more complex and you do not want to manually type out all relevant paths, this class can be easily extended and adapted.

package: processing

Exposes three modules: extract, transform, visualisation. extract exposes the FileManager which can be used to extract the relevant features out of the branches of a root file. transform exposes useful functions like select_feature in order to make cuts and reweight_feature. Take note that select_feature is not the most efficient way of doing cuts, for more efficient usage use the functionality of uproot3 directly. visualisation exposes reweight_comparing_plot in order to plot 3 diagrams, two original features and the reweighted feature.