Data

The 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:

1. Higgs boson signal (\(H \rightarrow \tau \tau\))

2. \(Z\) boson background (\(Z \rightarrow \tau \tau\))

3. Diboson background (\( VV \rightarrow \tau \tau\))

4. ttbar background (\(t \bar{t}\))

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 state 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:

\( w = \frac{\textrm{Cross-Section} ~ \times ~ \textrm{Luminosity}}{\textrm{Total number of generated events}} \)

The challenge is considering a scenario of analyzing proton-proton collision data of \(10 ~\textrm{fb} ^{-1}\) luminosity collected by the ATLAS experiment.

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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 \(w_i\).
Label	The event label \(y_i \in \{1,0\}\) (1 for signal, 0 for background).
Detailed Label	The event detailed label \(\in\{ htautau, ztautau, diboson, ttbar \}\)

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 \(\sqrt{{p_x}^2 + {p_y}^2}\) of the hadronic tau.
PRI_had_eta	The pseudorapidity \(\eta\) of the hadronic tau.
PRI_had_phi	The azimuth angle \(\phi\) of the hadronic tau.
PRI_lep_pt	The transverse momentum \(\sqrt{{p_x}^2 + {p_y}^2}\) of the lepton (electron or muon).
PRI_lep_eta	The pseudorapidity \(\eta\) of the lepton.
PRI_lep_phi	The azimuth angle \(\phi\) of the lepton.
PRI_met	The missing transverse energy \({E}^{miss}_{T}\).
PRI_met_phi	The azimuth angle \(\phi\) 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 \(\sqrt{{p_x}^2 + {p_y}^2}\) 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 \(\eta\) of the leading jet (undefined if PRI_jet_num = 0).
PRI_jet_leading_phi	The azimuth angle \(\phi\) of the leading jet (undefined if PRI_jet_num = 0).
PRI_jet_subleading_pt	The transverse momentum \(\sqrt{{p_x}^2 + {p_y}^2}\) 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 \(\eta\) of the subleading jet (undefined if PRI_jet_num ≤ 1).
PRI_jet_subleading_phi	The azimuth angle \(\phi\) 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 varibales with the help of derived_quantities.py. When the test sets are made they inherently have derived quantities. (train set doesnt have derived quantities as they change after systematics is applied. Hence partipants are adviced to use systematics function for this.)

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 \(\tau_{had}\)	1
Number of \(\tau_{lep}\)	1
\(p_T \tau_{had}\)	> 20GeV	> 26GeV
\(p_T \tau_{lep}\)	> 20GeV	> 20GeV
\(p_T leading jet\)	> 20GeV	> 26GeV
\(p_T subleading jet\)	> 20GeV	> 26GeV
Charege	Opposite Charges

⚠️ Note: The Post selection cuts are the cuts made after systematics is applied.

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How to get Public Data?

Download the Neurips_Public_data_26_08_2024 (6.5 GB)

or use the following command to download using terminal

wget -O public_data.zip https://www.codabench.org/datasets/download/b9e59d0a-4db3-4da4-b1f8-3f609d1835b2/