Skip to content
Merged
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
50 changes: 47 additions & 3 deletions docs/advanced-specifics/pwgud.md
Original file line number Diff line number Diff line change
Expand Up @@ -4,13 +4,57 @@ title: PWG-UD
---

# Ultra-peripheral collisions and diffraction (UD) analysis framework
The **PWG-UD** (Ultra-peripheral and Diffractive) working group focuses on the study of photon-induced and diffractive processes in heavy-ion and proton–proton collisions, as well as cosmic rays.

## Get started

In the past, several hands-on sessions and tutorials have been organised within the **PWG-UD** to introduce the analysis framework.
A list of the corresponding Indico events is provided below.

### Past tutorials and hands-on sessions

<!-- markdown-link-check-disable -->

- **[UD/O2 hands-on sessions](https://indico.cern.ch/event/1425820/timetable/#b-571496-pwg-ud-ultra-peripher) from O2 Analysis Tutorial 4.0 (16 October 2024)** - Introduction to the O² framework for UD analyses with practical examples. Includes introduction, [Event selection for UPC](https://indico.cern.ch/event/1425820/contributions/6176711/attachments/2948608/5189086/0-ud-firstpart.mp4),
[Data analysis with UD tables](https://indico.cern.ch/event/1425820/contributions/6176712/attachments/2948661/5189090/0-ud-anisa.mp4) and [MC simulation](https://indico.cern.ch/event/1425820/contributions/6176715/attachments/2948620/5189095/0-ud-simone.mp4).
- Example tasks:
- [`UDTutorial_05.cxx`](https://github.com/AliceO2Group/O2Physics/blob/master/Tutorials/PWGUD/UDTutorial_05.cxx) – Two-pion analysis at midrapidity
- [`UDTutorial_06.cxx`](https://github.com/AliceO2Group/O2Physics/blob/master/Tutorials/PWGUD/UDTutorial_06.cxx) – Forward muon analysis
- [`UDTutorial_07.cxx`](https://github.com/AliceO2Group/O2Physics/blob/master/Tutorials/PWGUD/UDTutorial_07.cxx) – Event-by-event tree creation

- **[UD/O2 hands-on sessions](https://indico.cern.ch/event/1326201/timetable/#b-528201-pwg-ud-ultra-peripher) from O2 Tutorial 3.0 (8 November 2023)** — Overview of UD tables and accesing MC data [Zoom recording part1](https://indico.cern.ch/event/1326201/contributions/5663204/attachments/2748184/4783585/ud1.mp4), [Zoom recording part2](https://indico.cern.ch/event/1326201/contributions/5663204/attachments/2748184/4783622/ud2.mp4).

- **[UD/O2 hands-on sessions](https://indico.cern.ch/event/1267433/timetable/#b-508750-parallel-hands-on-pwg) from O2 Tutorial 2.0 (27 April 2023)** — Introduction to UD tables, task developement and hands-on sessions, [Zoom recording part1](https://indico.cern.ch/event/1267433/sessions/490459/attachments/2636549/4565155/ud-piece1.mp4), [Zoom recording part2](https://indico.cern.ch/event/1267433/sessions/490459/attachments/2636549/4565156/ud2.mp4).

- **[O2 Analysis Tutorial (13–14 October 2022)](https://indico.cern.ch/event/1200252/timetable/#20221013.detailed)** — General introduction to the O2 analysis framework.

<!-- markdown-link-check-enable -->

## Contact
<!-- markdown-link-check-disable -->
Mattermost channels: [PWG-UD O2 analyses](https://mattermost.web.cern.ch/alice/channels/pwg-ud-o2-analyses), [PWG-UD general](https://mattermost.web.cern.ch/alice/channels/pwg-ud), [O2AT-PWG-UD](https://mattermost.web.cern.ch/alice/channels/o2at-pwg-ud)
<!-- markdown-link-check-enable -->

## Code

- The codebase can be found in the
[`PWGUD`](https://github.com/AliceO2Group/O2Physics/tree/master/PWGUD) directory.
.h).
- The PWG-UD analysis code is located in the directory
[`PWGUD`](https://github.com/AliceO2Group/O2Physics/tree/master/PWGUD)
- Data model can be found here - [UDTables.h](https://github.com/AliceO2Group/O2Physics/blob/master/PWGUD/DataModel/UDTables.h)
- Table produced by skimming and selecting event with double gap topology at midrapidity - [DGCandProducer.cxx](https://github.com/AliceO2Group/O2Physics/blob/master/PWGUD/TableProducer/DGCandProducer.cxx)
- Class for event selection with double gap at midrapidity - [DGSelector.h](https://github.com/AliceO2Group/O2Physics/blob/master/PWGUD/Core/DGSelector.h)
- Table produced by skimming and selecting event with single gap topology at midrapidity - [SGCandProducer.cxx](https://github.com/AliceO2Group/O2Physics/blob/master/PWGUD/TableProducer/SGCandProducer.cxx)
- Class for event selection with single topology at midrapidity - [SGSelector.h](https://github.com/AliceO2Group/O2Physics/blob/master/PWGUD/Core/SGSelector.h)
- Class for track selection with single gap topology at midrapidity - [SGTrackSelector.h](https://github.com/AliceO2Group/O2Physics/blob/master/PWGUD/Core/SGTrackSelector.h)
- Table produced by skimming and selecting event with muon arm at forward rapidity - [UPCCandidateProducer.cxx](https://github.com/AliceO2Group/O2Physics/blob/master/PWGUD/TableProducer/UPCCandidateProducer.cxx)
- Utility and helper functions: [UDHelpers.h](https://github.com/AliceO2Group/O2Physics/blob/master/PWGUD/Core/UDHelpers.h)
- Utility and helper functions: [`Tasks/CMakeLists.txt`](https://github.com/AliceO2Group/O2Physics/blob/master/PWGUD/Tasks/CMakeLists.txt)
- Quality assurance (QA) tasks: [`AQC`](https://github.com/AliceO2Group/O2Physics/tree/master/PWGUD/AQC)

## AliHyperloop
<!-- markdown-link-check-disable -->
[UD Hyperloop analyses](https://alimonitor.cern.ch/hyperloop/all-analyses) with [JIRA tickets](https://its.cern.ch/jira/projects/PWGUD/issues/PWGUD-11?filter=allopenissues)
<!-- markdown-link-check-enable -->

## Framework structure
A schematic diagram of the typical workflow for a PWG-UD analysis is shown below.
<div align="center"> <img src="../images/UD-Analysis-framework_v2.png" width="800px" alt="PWGUD analysis framework"> </div>