[PWGHF] Replace UPC Lc THnSparse with TTree

[Rrantu]

This PR introduces a transition from THnSparse to TTree in the UPC Lc analysis.
Main changes:

• Added UPC Lc columns and tables in utilsUpcHf.h
• Implemented production and filling of TTree in taskLc.cxx
• Removed UPC-related axes from the THnSparse

[github-actions]

O2 linter results: ❌ 0 errors, ⚠️ 0 warnings, 🔕 0 disabled

[vkucera]

@Rrantu Columns and tables are parts of the data model. They don't belong in the utility headers.

[Rrantu]

Hi @vkucera, thanks for the comment, where would you recommend moving the columns and tables to? Would it be acceptable to define them directly in the task?

[vkucera]

Hi @vkucera, thanks for the comment, where would you recommend moving the columns and tables to? Would it be acceptable to define them directly in the task?

Yes, if the tables are not used anywhere else, please put them in the task.

[Rrantu]

Hi @vkucera, thanks for the comment, where would you recommend moving the columns and tables to? Would it be acceptable to define them directly in the task?

Yes, if the tables are not used anywhere else, please put them in the task.

Thanks! I‘ve moved them to the task file

[vkucera]

@Rrantu A conceptual question: Why can you not use the THnSparse?

[Rrantu]

@Rrantu A conceptual question: Why can you not use the THnSparse?

Thanks for the question! For large statistics, merging THnSparse objects becomes very heavy, making it difficult to obtain merged AnalysisResults.root. I also need to repeatedly adjust selections on multiple axes during the offline analysis. Projections from high-dimensional THnSparse are not very flexible.

[lubynets]

Dear @Rrantu, @vkucera, all codeowners, sorry for interfering,
Are Tasks, and not TableProducers, supposed to produce trees? https://aliceo2group.github.io/analysis-framework/docs/gettingstarted/theo2physicsrepo.html#folder-structure

[vkucera]

Dear @Rrantu, @vkucera, all codeowners, sorry for interfering, Are Tasks, and not TableProducers, supposed to produce trees? https://aliceo2group.github.io/analysis-framework/docs/gettingstarted/theo2physicsrepo.html#folder-structure

No, they are not.

[Rrantu]

Hi @lubynets, Thanks for the question. In this case, the tables are only used within this task, and the trees are produced specifically for this analysis. Also, there are other tasks that produce trees in a similar way.