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Welcome to the wiki for lhcb-ntuples-gen, the repository that generates the ntuples for some LHCb analyses at UMD, currently just run 2 \(R(D^{(*)})\) analysis. In this section, you'll find useful information for installing the required dependencies for this project, as well as the usage of some tools, such as git-annex, that will be used in this project.

Generation of analysis ntuples

The ntuples1 generation is separated into:

  1. STEP 1: Use LHCb's DaVinci to generate ntuples from raw LHCb data2. Follow this section to install required programs. Use this manual to learn how to use DaVinci locally. Follow this section to learn submitting DaVinci jobs to the GRID.
  2. STEP 2: Use babymaker frame work to do slimming, skimming, and additional calculation on previous ntuples, generating new ntuples. Follow these two sections for installation. A general guide for generating step-2 ntuple can be found here.

Note

These two steps have separate dependencies. If you only need to run one step, just follow the installation instruction for that particular step.

Info

  • The step-1 and step-2 ntuples have the following naming conventions.
  • For some tips on the general development of this project, see here

Directory structures

.
├── archive      # storage for plots, csv, and some old code
├── docs
├── ganga
├── gen          # output produced by make rules, e.g. ntuple, cutflow MD
├── include      # headers
│   └── functor
│       └── rdx  # RDX-specific headers
├── lib
│   └── python   # Python submodules, e.g. pyBabyMaker
├── ntuples      # storage for (mostly) GRID-produced ntuples
├── postprocess
│   ├── cpp_templates  # C++ templates for babymaker
│   ├── rdx-run1
│   ├── rdx-run2
│   ├── ref-rdx-run1   # For Phoebe's sample ntuples
│   └── skims          # For branch removal at lxplus level
├── run1-rdx     # DaVinci scripts, sample ntuples for RDX run 1
├── run2-rdx     # ^^^^ for RDX run 2
├── scripts      # plotting, cutflow, and utility scripts
├── studies      # One-off studies
└── workflows    # workflows for ntuple production, cutflow, etc.
    └── rdx

Modifying this wiki

This wiki is written in a series of markdown files (.md) committed to the docs folder of the lhcb-ntuples-gen repository. The structure of the wiki is defined in mkdocs.yml. This file contains the title of each page in the wiki, and the markdown file that defines that page.

To modify the wiki just modify mkdocs.yml or the .md files, and commit the changes to the repo. In about a minute Github Action will deploy the new website to https://umd-lhcb.github.io/lhcb-ntuples-gen/.

To view the website locally (for instance, before committing), you will need to install mkdocs and the material theme 

pip install --user -r docs/requirements.txt
Then, from lhcb-ntuples-gen you generate the website at the local address http://127.0.0.1:8000 with the command 
mkdocs serve

Note

If you have problems installing mkdocs, you can also install it and run it inside nix with

nix develop  # Enter the nix shell in lhcb-ntuples-gen
pip install -r docs/requirements.txt

Version control systems (VCS)

This project requires the following VCS to be installed in your system:

  • git: for source code version control
  • git-annex (that supports v7 repository format): for data file version control

To install these programs, please follow this section. In addition, we provide a brief introduction on the usage of git-annex.

  1. .root files that can be processed by DaVinci, ROOT, and many other tools. ↩

  2. .dst files that directly come from CERN. ↩