DOI: 10.5281/zenodo.15131565
title: FAIR Universe - HiggsML Uncertainty Challenge Public Dataset

description: HiggsML Uncertainty Challenge Public Dataset

This dataset has been created for the HiggsML Uncertainty Challenge, a NeurIPS 2024 competition. A detailed documentation is available in the challenge white paperThe tabular dataset is created using the particle physics simulation tools Pythia 8.2 and Delphes 3.5.0. The proton-proton collision events are generated with a center of mass energy of 13 TeV using Pythia8. Subsequently, these events undergo the Delphes tool to produce simulated detector measurements. We used an ATLAS-like detector description to make the dataset closer to experimental data. The events are divided into two groups:



Higgs boson signal (H→ττ)

ZZ boson background (Z→ττ)

Diboson background (VV→ττ)

ttbar background (ttˉ)


 




Process
Number Generated
LHC Events
Label


Higgs 
52 040 227 
1015 
signal


Z Boson
160 383 358
1 002 395
background


Di-Boson
605 118
3 783
background


ttbar
7 070 398
44 192
background




⚠️ Note: The "LHC events" is the average number in this category in a pseudo-experiment corresponding to running of the Large Hadron Collider for 10 fb−1, corresponding to approximately 800 billion inelastic proton collisions, or 2 weeks in summer 2024 conditions

Higgs Signal:

The Higgs bosons are produced with all possible production modes and decay into two tau leptons. The tau leptons are further allowed to decay into all possible final states, but only final states with one lepton (electron or muon) and one hadron tau decay are kept.

Z boson Background:

Only background events coming from Z bosons are included in this challenge. While simulating the process, interference effects between Z bosons and photons are included. Similar to signal events, only the tau-tau decay mode of the Z boson is included in the dataset.



⚠️ Note:

The training events have weights.

Event Weights:

Event weights are defined as:

w=Cross-Section × LuminosityTotal number of generated eventsw=Total number of generated eventsCross-Section × Luminosity

The challenge is considering a scenario of analyzing proton-proton collision data of 10 fb−1 luminosity collected by the ATLAS experiment.


Features in the data

Prefix-less variables

Weight, Label, DetailedLabel, have a special role and should NOT be used as regular features for the model:




Variable
Description




Weight
The event weight wi


Label
The event label yi ∈ 1,0  (1 for signal, 0 for background).


Detailed Label
The event detailed label ∈ htautau, ztautau, diboson, ttbar




Primary Features

The variables prefixed with PRI (for PRImitives) are “raw” quantities about the bunch collision as measured by the detector, essentially parameters of the momenta of particles.




Variable
Description




PRI_had_pt
The transverse momentum px2+py2 of the hadronic tau.


PRI_had_eta
The pseudorapidity η of the hadronic tau.


PRI_had_phi
The azimuth angle ϕ of the hadronic tau.


PRI_lep_pt
The transverse momentum px2+py2 of the lepton (electron or muon).


PRI_lep_eta
The pseudorapidity η of the lepton.


PRI_lep_phi
The azimuth angle ϕ of the lepton.


PRI_met
The missing transverse energy ETmiss.


PRI_met_phi
The azimuth angle ϕ of the missing transverse energy.


PRI_jet_num
The number of jets (integer with a value of 0, 1, 2 or 3; possible larger values have been capped at 3).


PRI_jet_leading_pt
The transverse momentum px2 + py2 of the leading jet, that is the jet with the largest transverse momentum (undefined if PRI_jet_num = 0).


PRI_jet_leading_eta
The pseudorapidity η of the leading jet (undefined if PRI_jet_num = 0).


PRI_jet_leading_phi
The azimuth angle ϕ of the leading jet (undefined if PRI_jet_num = 0).


PRI_jet_subleading_pt
The transverse momentum px2+py2 of the leading jet, that is, the jet with the second largest transverse momentum (undefined if PRI_jet_num ≤ 1).


PRI_jet_subleading_eta
The pseudorapidity η of the subleading jet (undefined if PRI_jet_num ≤ 1).


PRI_jet_subleading_phi
The azimuth angle ϕ of the subleading jet (undefined if PRI_jet_num ≤ 1).


PRI_jet_all_pt
The scalar sum of the transverse momentum of all the jets of the events.




Derived Features

These variables are derived from the primary variables with the help of derived_quantities.py. 




Variable
Description




DER_mass_transverse_met_lep
The transverse mass between the missing transverse energy and the lepton.


DER_mass_vis
The invariant mass of the hadronic tau and the lepton.


DER_pt_h
The modulus of the vector sum of the transverse momentum of the hadronic tau, the lepton and the missing transverse energy vector.


DER_deltaeta_jet_jet
The absolute value of the pseudorapidity separation between the two jets (undefined if PRI_jet_num ≤ 1).


DER_mass_jet_jet
The invariant mass of the two jets (undefined if PRI_jet_num ≤ 1).


DER_prodeta_jet_jet
The product of the pseudorapidities of the two jets (undefined if PRI_jet_num ≤ 1).


DER_deltar_had_lep
The R separation between the hadronic tau and the lepton.


DER_pt_tot
The modulus of the vector sum of the missing transverse momenta and the transverse momenta of the hadronic tau, the lepton, the leading jet (if PRI_jet_num ≥ 1) and the subleading jet (if PRI_jet_num = 2) (but not of any additional jets).


DER_sum_pt
The sum of the moduli of the transverse momenta of the hadronic tau, the lepton, the leading jet (if PRI_jet_num ≥ 1) and the subleading jet (if PRI_jet_num = 2) and the other jets (if PRI_jet_num = 3).


DER_pt_ratio_lep_tau
The ratio of the transverse momenta of the lepton and the hadronic tau.


DER_met_phi_centrality
The centrality of the azimuthal angle of the missing transverse energy vector w.r.t. the hadronic tau and the lepton.


DER_lep_eta_centrality
The centrality of the pseudorapidity of the lepton w.r.t. the two jets (undefined if PRI_jet_num ≤ 1).




Preselection Cuts




Criteria
Pre-selected cut
Post selection cut




Number of τhad
1
 


Number of τlep
1
 


pTτhad
> 20GeV
> 26GeV


pTτleppTτlep
> 20GeV
> 20GeV


pTleadingjet
> 20GeV
> 26GeV


pTsubleadingjet
> 20GeV
> 26GeV


Charge
Opposite Charges
 




⚠️ Note: The post-selection cuts are the cuts made after systematics is applied.⚠️ Note: The Dataset might not be properly shuffled. One could use dataset.py from the dataset repository (see below). 

 

Utility Software

Alongside the dataset, a GitHub repository with the relevant code for reading and analysing it is made available. This includes a Jupyter notebook starting kit, simple baseline models, and code to run the challenge and generate the score. The repository also has a sample dataset, a subset of the main dataset, to let users experience the challenge software without downloading the much larger dataset.The code for dataset generation is provided in a dedicated repository: https://github.com/FAIR-Universe/genHEPdata. This repository also contains a Dockerfile, which facilitates the installation of the necessary software dependencies.