TPS-Onia2MuMu: A C++ repository from Endymion2288

General Info

Measuring the cross section of prompt $J/\psi+J/\psi+\Upsilon$ prodution in pp collision on CMS.

Aimed at providing measurement result for studying parton correlation in proton and background estimation for BSM searches.

Using CMSSW_13_0_2. Inherited most of the code from AliceQuen/Onia2MuMu. (cr. Qin Junkai at Dept. of Physics, Tsinghua University)

Supervised under Prof. Hu Zhen at Dept. of Physics, Tsinghua University.

Match $\mu^+\mu^-$ pairs using vertex fitting. (Track geometry only.)
Create $J/\psi$ and $\Upsilon$ candidates using $\mu^+\mu^-$ pairs. (Dynamics required. Mass window, pT selection and other restrictions required.)
Matching $J/\psi$ and $\Upsilon$ candidates from one single vertex . (Track geometry only. May check $c\tau$ distribution.)

void LoadMC() Load MC results if doMC == true.
Some other code for initialization
Import trigger results and save for possible trigger matching.
Harvest muons from tracks. Loop over muon pairs.
For muon pair candidataes, apply a crude selection with "opposite-charge criterion" and mass window cut. ( For $J/\psi$, consider mass range $[1.0, 4.0]$. For $\Upsilon$, consider mass range $[8.0, 12.0]$. )
Apply kinematic fitting for each pair to vertices.
Store valid muon pairs by category. ($J/\psi$ or $\Upsilon$)
Use non-overlapping muon pairs to form $J/\psi$ and $\Upsilon$ candidates. (Careful not to directly store iterators! Use pointers instead.)
Store the candidates and corresponding muon pairs.

git pull Pull the latest changes from the remote repository.
git add . Add all files to the staging area after making changes.
git commit Commit the changes. A text editor will pop up for you to write the commit message. Alternatively, you can use git commit -m "<message>" to write the message directly.
git push Push the changes to the default remote repository. (Usually origin.)

git branch List all branches. The current branch is marked with a *.
git branch -a List all branches, including remote branches.
git branch -c <branch> Create a new branch named <branch>. It will be created from the current branch.
git checkout <branch> Switch to the branch named <branch>. Alternatively, you can use git switch <branch>.
git switch -c <branch> A shortcut: create a new branch named <branch> and switch to it.
git branch -d <branch> Delete the branch named <branch>. Use -D to force deletion.
git merge <branch> Merge the branch named <branch> into the current branch.

git remote List all remote repositories.
git remote add <name> <url> Add a new remote repository named <name> with URL <url>.
git remote remove <name> Remove the remote repository named <name>. This only removes the remote repository from the local repository's configuration. It does not delete the remote repository itself.
git push <name> Push the changes to the remote repository named <name>. This is useful when you have multiple remote repositories. In this project, we use origin and Tsinghua. The former is on GitHub, while the the latter is a mirror repository on Tsinghua's GitLab. They are kept in sync by the project maintainers.
git push --set-upstream <name> <branch> Push the changes to the remote repository named <name> and set the upstream branch to <branch>. This is useful when you are pushing to a new branch on the remote repository.

Always do git pull before starting off today's work!
To do some development from someone else's work, consider using git switch -c <branch> to begin your own work on a separate branch.
After finishing your work, do git push --set-upstream <name> <branch> to push your work to the remote repository <name>.
To merge your work into the main branch, access the remote repository and create a pull request. The project maintainers will review your work and merge it into the main branch.