Skip to content

[PWGCF] Add Lambda-proton balance function analysis task - #17838

Open
Anoop1379 wants to merge 8 commits into
AliceO2Group:masterfrom
Anoop1379:Lambda-Proton-Update
Open

[PWGCF] Add Lambda-proton balance function analysis task#17838
Anoop1379 wants to merge 8 commits into
AliceO2Group:masterfrom
Anoop1379:Lambda-Proton-Update

Conversation

@Anoop1379

Copy link
Copy Markdown

This PR introduces the lambda-proton-balance-function analysis task (lambdaProtonBalanceFunction.cxx) under PWGCF/TwoParticleCorrelations/Tasks to measure single- and two-particle density correlations and evaluate the Lambda-proton balance function.

This contains:

  1. Physics Observables:
  • Computes rho1 and rho2 density distributions in (Delta-eta, Delta-phi) and (Delta-y, Delta-phi) unrolled spaces.
  • Evaluates all baryon-baryon and baryon-antibaryon pairs (Lambda-p, Lambda-pbar, AntiLambda-p, AntiLambda-pbar) as well as p-p baseline and Lambda-Lambda pairs.
  • Provides pT-differential pair correlation histograms.
  1. Track and Particle Selections:
  • Primary protons and antiprotons selected using standard TPC/ITS track quality, tight DCAxy/DCAz cuts, and combined TPC + TOF PID with configurable momentum switch threshold.
  • Lambda and AntiLambda candidates reconstructed through V0 topological cuts (CosPA, decay radius, DCA to PV, daughter TPC nSigma PID, and K0s mass rejection window).
  1. Corrections and QA Diagnostics:
  • Primary proton vs. V0 daughter proton candidate overlap rejection (autocorrelation / split-track veto) with dedicated ProtonVetoQA diagnostics.
  • Event-level pileup monitoring and cutflow tracking.

Validation:

  • Passed o2_linter.py checks with 0 errors.
  • Formatted according to ALICE conventions using clang-format.
  • Executable registered in CMakeLists.txt.

1. Measures single-particle (rho1) and two-particle (rho2) density distributions in (delta_eta, delta_phi) and (delta_y, delta_phi) bins to evaluate the Lambda-proton balance function.
2. Evaluates all pair combinations: Lambda-p, Lambda-pbar, AntiLambda-p, and AntiLambda-pbar, along with p-p baseline and Lambda-Lambda pairs.
3. Includes pT-differential pair correlation histograms.
4. Selects primary (anti)protons using TPC/ITS quality cuts, DCA cuts, and combined TPC + TOF PID with momentum threshold switch.
5. Reconstructs Lambda and AntiLambda candidates via V0 topology, daughter PID, and K0s mass rejection window.
6. Implements primary-proton vs. V0 daughter-proton overlap veto to eliminate autocorrelation / split-track artifacts, tracked by ProtonVetoQA.
7. Includes comprehensive QA.
@github-actions

github-actions Bot commented Sep 9, 2026

Copy link
Copy Markdown

O2 linter results: ❌ 1 errors, ⚠️ 116 warnings, 🔕 0 disabled

Anoop1379 and others added 3 commits September 9, 2026 18:05
Removed unnecessary passDCA check for proton tracks.
Please consider the following formatting changes to AliceO2Group#17838
@wenyaCern

Copy link
Copy Markdown
Collaborator

Hi @Anoop1379 , please fix the errors reported by the o2-linter check

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

Development

Successfully merging this pull request may close these issues.

3 participants