{
"cells": [
{
"cell_type": "markdown",
"id": "ea2b081f",
"metadata": {},
"source": [
"# df102_NanoAODDimuonAnalysis\n",
"Show how NanoAOD files can be processed with RDataFrame.\n",
"\n",
"This tutorial illustrates how NanoAOD files can be processed with ROOT\n",
"dataframes. The NanoAOD-like input files are filled with 66 mio. events\n",
"from CMS OpenData containing muon candidates part of 2012 dataset\n",
"([DOI: 10.7483/OPENDATA.CMS.YLIC.86ZZ](http://opendata.cern.ch/record/6004)\n",
"and [DOI: 10.7483/OPENDATA.CMS.M5AD.Y3V3](http://opendata.cern.ch/record/6030)).\n",
"The macro matches muon pairs and produces an histogram of the dimuon mass\n",
"spectrum showing resonances up to the Z mass.\n",
"Note that the bump at 30 GeV is not a resonance but a trigger effect.\n",
"\n",
"More details about the dataset can be found on [the CERN Open Data portal](http://opendata.web.cern.ch/record/12341).\n",
"\n",
"\n",
"\n",
"\n",
"**Author:** Stefan Wunsch (KIT, CERN) \n",
"This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Tuesday, May 19, 2026 at 08:10 PM."
]
},
{
"cell_type": "code",
"execution_count": 1,
"id": "8d460b3a",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:10:29.858486Z",
"iopub.status.busy": "2026-05-19T20:10:29.858289Z",
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"shell.execute_reply": "2026-05-19T20:10:30.924638Z"
}
},
"outputs": [],
"source": [
"import ROOT"
]
},
{
"cell_type": "markdown",
"id": "3e4560d8",
"metadata": {},
"source": [
"Enable multi-threading"
]
},
{
"cell_type": "code",
"execution_count": 2,
"id": "7d01e130",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:10:30.926991Z",
"iopub.status.busy": "2026-05-19T20:10:30.926853Z",
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"shell.execute_reply": "2026-05-19T20:10:31.053381Z"
}
},
"outputs": [],
"source": [
"ROOT.ROOT.EnableImplicitMT()"
]
},
{
"cell_type": "markdown",
"id": "7b575988",
"metadata": {},
"source": [
"Create dataframe from NanoAOD files"
]
},
{
"cell_type": "code",
"execution_count": 3,
"id": "a8be9c2e",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:10:31.070289Z",
"iopub.status.busy": "2026-05-19T20:10:31.070144Z",
"iopub.status.idle": "2026-05-19T20:10:31.872951Z",
"shell.execute_reply": "2026-05-19T20:10:31.872500Z"
}
},
"outputs": [],
"source": [
"df = ROOT.RDataFrame(\"Events\", \"root://eospublic.cern.ch//eos/opendata/cms/derived-data/AOD2NanoAODOutreachTool/Run2012BC_DoubleMuParked_Muons.root\")"
]
},
{
"cell_type": "markdown",
"id": "811eb61c",
"metadata": {},
"source": [
"For simplicity, select only events with exactly two muons and require opposite charge"
]
},
{
"cell_type": "code",
"execution_count": 4,
"id": "21de1200",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:10:31.901282Z",
"iopub.status.busy": "2026-05-19T20:10:31.901114Z",
"iopub.status.idle": "2026-05-19T20:10:32.103910Z",
"shell.execute_reply": "2026-05-19T20:10:32.103406Z"
}
},
"outputs": [],
"source": [
"df_2mu = df.Filter(\"nMuon == 2\", \"Events with exactly two muons\")\n",
"df_os = df_2mu.Filter(\"Muon_charge[0] != Muon_charge[1]\", \"Muons with opposite charge\")"
]
},
{
"cell_type": "markdown",
"id": "f6dafaff",
"metadata": {},
"source": [
"Compute invariant mass of the dimuon system"
]
},
{
"cell_type": "code",
"execution_count": 5,
"id": "c30334a2",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:10:32.112209Z",
"iopub.status.busy": "2026-05-19T20:10:32.112072Z",
"iopub.status.idle": "2026-05-19T20:10:32.254064Z",
"shell.execute_reply": "2026-05-19T20:10:32.253406Z"
}
},
"outputs": [],
"source": [
"df_mass = df_os.Define(\"Dimuon_mass\", \"InvariantMass(Muon_pt, Muon_eta, Muon_phi, Muon_mass)\")"
]
},
{
"cell_type": "markdown",
"id": "9c2b7ba0",
"metadata": {},
"source": [
"Make histogram of dimuon mass spectrum. Note how we can set titles and axis labels in one go."
]
},
{
"cell_type": "code",
"execution_count": 6,
"id": "d9e1559a",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:10:32.266498Z",
"iopub.status.busy": "2026-05-19T20:10:32.266328Z",
"iopub.status.idle": "2026-05-19T20:10:32.479036Z",
"shell.execute_reply": "2026-05-19T20:10:32.477385Z"
}
},
"outputs": [],
"source": [
"h = df_mass.Histo1D((\"Dimuon_mass\", \"Dimuon mass;m_{#mu#mu} (GeV);N_{Events}\", 30000, 0.25, 300), \"Dimuon_mass\")"
]
},
{
"cell_type": "markdown",
"id": "3e8fd03d",
"metadata": {},
"source": [
"Request cut-flow report"
]
},
{
"cell_type": "code",
"execution_count": 7,
"id": "6b3ba4f0",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:10:32.492288Z",
"iopub.status.busy": "2026-05-19T20:10:32.492145Z",
"iopub.status.idle": "2026-05-19T20:10:33.337349Z",
"shell.execute_reply": "2026-05-19T20:10:33.336647Z"
}
},
"outputs": [],
"source": [
"report = df_mass.Report()"
]
},
{
"cell_type": "markdown",
"id": "7c390092",
"metadata": {},
"source": [
"Produce plot"
]
},
{
"cell_type": "code",
"execution_count": 8,
"id": "aa8abba2",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:10:33.341350Z",
"iopub.status.busy": "2026-05-19T20:10:33.341201Z",
"iopub.status.idle": "2026-05-19T20:10:48.061634Z",
"shell.execute_reply": "2026-05-19T20:10:48.060999Z"
}
},
"outputs": [
{
"name": "stderr",
"output_type": "stream",
"text": [
"Info in : pdf file dimuon_spectrum.pdf has been created\n"
]
},
{
"data": {
"text/html": [
"\n",
"\n",
"\n",
"
\n",
"\n",
"\n",
"\n"
],
"text/plain": [
""
]
},
"metadata": {},
"output_type": "display_data"
}
],
"source": [
"ROOT.gStyle.SetOptStat(0); ROOT.gStyle.SetTextFont(42)\n",
"c = ROOT.TCanvas(\"c\", \"\", 800, 700)\n",
"c.SetLogx(); c.SetLogy()\n",
"\n",
"h.SetTitle(\"\")\n",
"h.GetXaxis().SetTitleSize(0.04)\n",
"h.GetYaxis().SetTitleSize(0.04)\n",
"h.Draw()\n",
"\n",
"label = ROOT.TLatex(); label.SetNDC(True)\n",
"label.DrawLatex(0.175, 0.740, \"#eta\")\n",
"label.DrawLatex(0.205, 0.775, \"#rho,#omega\")\n",
"label.DrawLatex(0.270, 0.740, \"#phi\")\n",
"label.DrawLatex(0.400, 0.800, \"J/#psi\")\n",
"label.DrawLatex(0.415, 0.670, \"#psi'\")\n",
"label.DrawLatex(0.485, 0.700, \"Y(1,2,3S)\")\n",
"label.DrawLatex(0.755, 0.680, \"Z\")\n",
"label.SetTextSize(0.040); label.DrawLatex(0.100, 0.920, \"#bf{CMS Open Data}\")\n",
"label.SetTextSize(0.030); label.DrawLatex(0.630, 0.920, \"#sqrt{s} = 8 TeV, L_{int} = 11.6 fb^{-1}\")\n",
"\n",
"c.SaveAs(\"dimuon_spectrum.pdf\")"
]
},
{
"cell_type": "markdown",
"id": "2a4415a3",
"metadata": {},
"source": [
"Print cut-flow report"
]
},
{
"cell_type": "code",
"execution_count": 9,
"id": "862635f5",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:10:48.071270Z",
"iopub.status.busy": "2026-05-19T20:10:48.071115Z",
"iopub.status.idle": "2026-05-19T20:10:48.244059Z",
"shell.execute_reply": "2026-05-19T20:10:48.243669Z"
}
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Events with exactly two muons: pass=31104343 all=61540413 -- eff=50.54 % cumulative eff=50.54 %\n",
"Muons with opposite charge: pass=24067843 all=31104343 -- eff=77.38 % cumulative eff=39.11 %\n"
]
}
],
"source": [
"report.Print()"
]
},
{
"cell_type": "markdown",
"id": "81120b28",
"metadata": {},
"source": [
"Draw all canvases "
]
},
{
"cell_type": "code",
"execution_count": 10,
"id": "15cb7444",
"metadata": {
"collapsed": false,
"execution": {
"iopub.execute_input": "2026-05-19T20:10:48.266073Z",
"iopub.status.busy": "2026-05-19T20:10:48.265879Z",
"iopub.status.idle": "2026-05-19T20:10:48.394825Z",
"shell.execute_reply": "2026-05-19T20:10:48.394312Z"
}
},
"outputs": [
{
"data": {
"text/html": [
"\n",
"\n",
"\n",
"
\n",
"\n",
"\n",
"\n"
],
"text/plain": [
""
]
},
"metadata": {},
"output_type": "display_data"
}
],
"source": [
"%jsroot on\n",
"from ROOT import gROOT \n",
"gROOT.GetListOfCanvases().Draw()"
]
}
],
"metadata": {
"kernelspec": {
"display_name": "Python 3",
"language": "python",
"name": "python3"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 3
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
"version": "3.12.12"
}
},
"nbformat": 4,
"nbformat_minor": 5
}