{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"![](\"http://files.oproject.org/img/HeaderOpenData.png\")
\n",
"\n",
"# CMS Open Data Example #4: Di-Electron Resonances\n",
"![](\"http://files.oproject.org/img/Zee.jpg\")
\n",
"## Import Modules and Turn on Javascript"
]
},
{
"cell_type": "code",
"execution_count": 12,
"metadata": {
"collapsed": false
},
"outputs": [],
"source": [
"from ROOT import TFile, TCanvas, TH1F, TLorentzVector, TH2F\n",
"\n",
"%jsroot on"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Read in Data from Input File"
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {
"collapsed": false
},
"outputs": [],
"source": [
"file = TFile(\"data/Dielectrons.root\",\"READ\");"
]
},
{
"cell_type": "markdown",
"metadata": {
"collapsed": true
},
"source": [
"# Compute Di-Electron Invariant Mass\n",
"Let's calculate the invariant mass $M$ of two electrons"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Setup a Canvas"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"Canvas = TCanvas()"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Declare Histograms"
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"histogram = TH1F(\"Invariant Mass\",\"ee mass; ee mass [GeV];Events\", 900, 2, 110)"
]
},
{
"cell_type": "markdown",
"metadata": {
"collapsed": true
},
"source": [
"## Loop Over the Events in the Data File\n",
"### Compute Di-Electron Invariant Mass "
]
},
{
"cell_type": "code",
"execution_count": 5,
"metadata": {
"collapsed": false
},
"outputs": [],
"source": [
"for diele in file.Dielectrons:\n",
" \n",
" electron1 = TLorentzVector(diele.Electron1_Px, diele.Electron1_Py, diele.Electron1_Pz, diele.Electron1_Energy)\n",
" \n",
" electron2 = TLorentzVector(diele.Electron2_Px, diele.Electron2_Py, diele.Electron2_Pz, diele.Electron2_Energy)\n",
" \n",
" InvariantMass = (electron1 + electron2).M()\n",
" \n",
" histogram.Fill(InvariantMass) "
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Plot the Di-Electron Invariant Mass Spectrum"
]
},
{
"cell_type": "code",
"execution_count": 6,
"metadata": {
"collapsed": false
},
"outputs": [
{
"data": {
"text/html": [
"\n",
"\n",
"
\n",
"\n",
"\n"
],
"text/plain": [
""
]
},
"metadata": {},
"output_type": "display_data"
}
],
"source": [
"histogram.Draw()\n",
"\n",
"Canvas.SetLogy()\n",
"\n",
"Canvas.Draw()"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Di-Electrons Exercise: \n",
"### Can You Spot the Di-Electron Resonances? \n",
"### Make a Histogram For Each One"
]
},
{
"cell_type": "code",
"execution_count": 14,
"metadata": {
"collapsed": false,
"scrolled": true
},
"outputs": [],
"source": [
"dielectroncharge = TH2F(\"dielectroncharge\", \"charge comparison; electron 1 charge; electron 2 charge\", 10, -2, 2, 10, -2, 2)"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": false
},
"outputs": [],
"source": []
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": []
}
],
"metadata": {
"kernelspec": {
"display_name": "Python 2",
"language": "python",
"name": "python2"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 2
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython2",
"version": "2.7.9"
}
},
"nbformat": 4,
"nbformat_minor": 0
}