There is some extra set up beyond cloning this repo required to get everything up and running. First there are some files missing in data/V0Data/ and data/V0MC/ which are excluded due to being device specific or being too large to keep in this repo.

• data/V0Data/: requires locCCDB/ and AO2D.root. These can be symbolic links to the relevant place on your system.

• data/V0MC/: requires locCCDB/ and aodmcs.txt. These can be symbolic links to the relevant place on your system.

In this example we will go from nothing to having a significance plot for dcapostopv on the K0.

1. First we will need to apply the cuts over the range that we want and on the files we want. The scripts V0Data_cut_runner.py or V0MC_cut_runner.py allow us to do this. To configure the cuts and default cuts you must edit scripts/cut_config.json.

   1. We could select: "dcapostopv": { "UpperLimit": 0.2, "LowerLimit": 0.0, "step": 0.005 }.
   2. and also select: "cuts_to_apply": { "dcanegtopv": false, "dcapostopv": true, "v0cospa": false, "dcav0dau": false, "v0radius": false },

   Make sure you save these changes before step 2.

2. From the root directory of this repo run python3 scripts/V0Data_cut_runner.py (IMPORTANT: Must be in alienv O2Physics environment). This will populate output/V0Data/ with files of the form AnalysisResults_dcanegtopv_0.05.root, which contain the parameter and cut value. (This is quite slow)

3. To get to a significance plot for these cuts we need to fit each of the K0 mass plots in the .root files produced in step 2. The script significance_runner.py allows us to do this. There are two variables to edit at the top of this file.

   1. isMC: Boolean to choose Data or MC.
   2. V0_index: 0 = K0, 1 = Lambda.

   For this example we would choose isMC = False and V0_index = 0. Make sure you save these changes before step 4.

4. From the root directory of this repo run python3 scripts/significance_runner.py. This will populate figures/batch_mass_plots/ with figures with names like K0Data_dcapostopv_0.05.pdf (This is mostly important just to check that the fits are behaving as expected). After this has finished running the results will be saved in output/significance.json and the plot output/figures/K0Data_significance_dcapostopv.pdf will be saved. You may get some warnings like WARN: No files found for cut parameter v0cospa. These are ok to ignore for now as this script tries all parameters but you may not have all the data files yet.

If a specific cut has already been performed before (meaning the output .root file already exists) then this is skipped as there is no need to recreate the file and therefore we can save time.

If a specific significance calculation has already been done before (meaning it already exists in significance.json) it will be skipped to save time as well.

If the python scripts are failing to run the MACROS: MACROS/SignificanceFit.C and MACROS/SignificancePlot.C then you may not have compiled the c++ files in lib/. This is done by, from the root directory of this repo, running python3 lib/lib_compile.py

Process for running MC cuts is a bit different but should be similar for significance. MC cuts are very very slow. For 80 cuts each for two parameters this takes many hours.

Contains all data relevant for running code in lib and MACROS. The relevant data or MC files are found in data/V0Data/ and data/V0MC/.

Contains root libraries for use in macros or independently using .L LibName.cpp at a root prompt. They need to be compiled before they will work with the MACROS that require them. They can be compiled together using python3 lib_compile.py.

Contains ROOT macros which can be executed using root MacroName.C or at a root prompt using .x MacroName.C.

Ideally all code that produce usefull data should store it here in a sensible subfolder.

Contains any scripts used for batch tasks.

Type cc7 (eprexa)

Start enviroment of O2 Physics software (eprexa):

• alienv enter O2Physics/latest-master-o2
• alienv enter O2Physics/latest-rl-o2

if on epldt003:

• alienv enter O2Physics/latest-d9ac9d44d3-o2