Statistical model for CMS-EXO-24-031

Statistical models for CMS-EXO-24-031 Introduction This repository contains the full statistical model for CMS Combine (version v8.2.0) related to the paper:"Search for light pseudoscalar bosons, pair-produced in Higgs boson decays in the four-electron final state in proton-proton collisions at √s = 13 TeV", by the CMS Collaboration. The instructions below include the commands needed to reproduce the workspaces used for the results presented in the publication.For additional technical documentation, please consult the CMS Combine documentation:https://github.com/cms-analysis/HiggsAnalysis-CombinedLimit/ Requirements The datacards (besides txt files) often include binary inputs such as ROOT files. This repository uses Git Large File Storage (Git LFS) to track them, which makes cloning more efficient. If you do not have git lfs installed, please follow the installation instructions:https://github.com/git-lfs/git-lfs#installing The results in the paper were obtained using Combine version: v8.2.0. Analysis specific instructions This analysis searches for Higgs boson decays into a pair of light pseudoscalar bosons (a/ALP), followed by:a → e⁺e⁻ Signal: H → AA → (e⁺e⁻)(e⁺e⁻) (often written as H → AA → 4e) Data: pp collisions at √s = 13 TeV, collected in 2016–2018, corresponding to 138 fb⁻¹ Mass range: m(A) = 10–100 MeV Lifetime range: ctau = 0–500 μm Parameter naming convention (mXlY) For parameters / card tags named as mXlY (e.g. m2l10), the interpretation is: ALP mass = X × 10 MeV Lifetime (ctau) = Y μm Example:m2l10 → mass = 2 × 10 MeV = 20 MeV, ctau = 10 μm. Repository layout inputs/card/Datacards in plain text format (.txt). This is where the Combine datacards are stored. inputs/Model/ROOT workspaces (WS) files used by the datacards. models/Analysis working directory containing the key scripts used to reproduce the main results.Typical contents include: run_AsymptoticLimits.sh run_likelihood_scan.sh run_ParameterImpact.sh Example commands Note: All tests are meant to be run from the inputs/ directory, and with Combine v8.2.0.This is because the datacards use relative paths to access files under Model/. Example commands are provided in dedicated scripts, depending on the target measurement. 1) Limit calculation (AsymptoticLimits) To get the 95% CL upper limit for a specific mass/lifetime point (e.g. 20 MeV, 10 μm): bash ../models/run_AsymptoticLimits.sh m2l10_Run2 We set: σ(ggH → AA → 4e) = 0.5 fb To convert the signal strength upper limit r into the branching ratio upper limit: BR upper limit = r_upper_limit × σ(ggH → AA → 4e) / σ(ggH) 2) 1D signal strength likelihood scan (MultiDimFit grid scan) Example for 20 MeV, 10 μm (you can change the parameter point by switching the card/tag): bash ../models/run_likelihood_scan.sh m2l10_Run2 3) Impacts (nuisance parameter impacts for a specific point) Example for 20 MeV, 10 μm: bash ../models/run_ParameterImpact.sh m2l10_Run2