Rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

ATLAS_2010_S8918562

Track-based minimum bias at 900 GeV and 2.36 and 7 TeV in ATLAS
Experiment: ATLAS (LHC)
Inspire ID: 882098
Status: VALIDATED
Authors:
  • Thomas Burgess
  • Andy Buckley
References: Beams: p+ p+
Beam energies: (450.0, 450.0); (1180.0, 1180.0); (3500.0, 3500.0) GeV
Run details:
  • $pp$ QCD interactions at 0.9, 2.36, and 7 TeV. Diffractive events should be included. Multiple kinematic cuts should not be required.

Measurements from proton-proton collisions at centre-of-mass energies of $\sqrt{s} = 0.9$, 2.36, and 7 TeV recorded with the ATLAS detector at the LHC. Events were collected using a single-arm minimum-bias trigger. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity and the relationship between the mean transverse momentum and charged-particle multiplicity are measured. Measurements in different regions of phase-space are shown, providing diffraction-reduced measurements as well as more inclusive ones. The observed distributions are corrected to well-defined phase-space regions, using model-independent corrections.

Source code: ATLAS_2010_S8918562.cc
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
// -*- C++ -*-

#include "Rivet/Analysis.hh"
#include "Rivet/Projections/ChargedFinalState.hh"

namespace Rivet {


  /// Rivet analysis class for ATLAS 2010 minimum bias analysis
  class ATLAS_2010_S8918562 : public Analysis {
  public:

    /// Helper for collectively filling Nch, pT, eta, and pT vs. Nch histograms
    void fillPtEtaNch(const ChargedFinalState& cfs, int nchcut, double weight,
                      Histo1DPtr h_nch, Histo1DPtr h_pt,
                      Histo1DPtr h_eta, Profile1DPtr h_ptnch = Profile1DPtr()) {

      // Get number of particles and skip if event fails cut
      const int nch = cfs.size();
      if (nch < nchcut) return;

      // Fill nch
      h_nch->fill(nch, weight);
      // Loop over particles, fill pT, eta and ptnch
      foreach (const Particle& p, cfs.particles()) {
        const double pt = p.pT();
        h_pt->fill(pt/GeV, weight/pt);
        h_eta->fill(p.eta(), weight);
        if (h_ptnch != 0) h_ptnch->fill(nch, pt/GeV, weight);
      }
    }


    /// Default constructor
    ATLAS_2010_S8918562() : Analysis("ATLAS_2010_S8918562") {
      _sumW_pt100_nch2 = 0;
      _sumW_pt100_nch20 = 0;
      _sumW_pt500_nch1 = 0;
      _sumW_pt500_nch6 = 0;
      _sumW_pt2500_nch1 = 0;
    }


    /// Initialization, called once before running
    void init() {
      // Projections
      const ChargedFinalState cfs100(-2.5, 2.5, 100.0*MeV);
      declare(cfs100, "CFS100");
      const ChargedFinalState cfs500(-2.5, 2.5, 500.0*MeV);
      declare(cfs500, "CFS500");
      const ChargedFinalState cfs2500(-2.5, 2.5, 2500.0*MeV);
      declare(cfs2500, "CFS2500");

      // Book histograms
      if (fuzzyEquals(sqrtS()/GeV, 900)) {
        _hist_pt100_nch2_nch = bookHisto1D(18, 1, 1);
        _hist_pt100_nch2_pt = bookHisto1D(11, 1, 1);
        _hist_pt100_nch2_eta = bookHisto1D(4, 1, 1);
        _hist_pt100_nch2_ptnch = bookProfile1D(24, 1, 1);

        _hist_pt100_nch20_nch = bookHisto1D(34, 1, 1);
        _hist_pt100_nch20_pt = bookHisto1D(30, 1, 1);
        _hist_pt100_nch20_eta = bookHisto1D(26, 1, 1);

        _hist_pt500_nch1_nch = bookHisto1D(15, 1, 1);
        _hist_pt500_nch1_pt = bookHisto1D(8, 1, 1);
        _hist_pt500_nch1_eta = bookHisto1D(1, 1, 1);
        _hist_pt500_nch1_ptnch = bookProfile1D(22, 1, 1);

        _hist_pt500_nch6_nch = bookHisto1D(20, 1, 1);
        _hist_pt500_nch6_pt = bookHisto1D(13, 1, 1);
        _hist_pt500_nch6_eta = bookHisto1D(6, 1, 1);

        _hist_pt2500_nch1_nch = bookHisto1D(36, 1, 1);
        _hist_pt2500_nch1_pt = bookHisto1D(32, 1, 1);
        _hist_pt2500_nch1_eta = bookHisto1D(28, 1, 1);
        _hist_pt2500_nch1_ptnch = bookProfile1D(38, 1, 1);

      } else if (fuzzyEquals(sqrtS()/GeV, 2360)) {

        _hist_pt500_nch1_nch = bookHisto1D(16, 1, 1);
        _hist_pt500_nch1_pt = bookHisto1D(9, 1, 1);
        _hist_pt500_nch1_eta = bookHisto1D(2, 1, 1);
        // This one histogram might be called while unbooked, so ensure its pointer is null!
        _hist_pt500_nch1_ptnch = Profile1DPtr();

      } else if (fuzzyEquals(sqrtS()/GeV, 7000)) {

        _hist_pt100_nch2_nch = bookHisto1D(19, 1, 1);
        _hist_pt100_nch2_pt = bookHisto1D(12, 1, 1);
        _hist_pt100_nch2_eta = bookHisto1D(5, 1, 1);
        _hist_pt100_nch2_ptnch = bookProfile1D(25, 1, 1);

        _hist_pt100_nch20_nch = bookHisto1D(35, 1, 1);
        _hist_pt100_nch20_pt = bookHisto1D(31, 1, 1);
        _hist_pt100_nch20_eta = bookHisto1D(27, 1, 1);

        _hist_pt500_nch1_nch = bookHisto1D(17, 1, 1);
        _hist_pt500_nch1_pt = bookHisto1D(10, 1, 1);
        _hist_pt500_nch1_eta = bookHisto1D(3, 1, 1);
        _hist_pt500_nch1_ptnch = bookProfile1D(23, 1, 1);

        _hist_pt500_nch6_nch = bookHisto1D(21, 1, 1);
        _hist_pt500_nch6_pt = bookHisto1D(14, 1, 1);
        _hist_pt500_nch6_eta = bookHisto1D(7, 1, 1);

        _hist_pt2500_nch1_nch = bookHisto1D(37, 1, 1);
        _hist_pt2500_nch1_pt = bookHisto1D(33, 1, 1);
        _hist_pt2500_nch1_eta = bookHisto1D(29, 1, 1);
        _hist_pt2500_nch1_ptnch = bookProfile1D(39, 1, 1);

      } else {
        throw LogicError("The ATLAS_2010_S8918562 analysis is only valid for sqrt(s) = 900, 2360 and 7000 GeV!");
      }

    }



    void analyze(const Event& event) {
      const double weight = event.weight();

      // 100 GeV final states
      if (!fuzzyEquals(sqrtS()/GeV, 2360)) {
        const ChargedFinalState& cfs100 = apply<ChargedFinalState>(event, "CFS100");
        // nch>=2
        if (cfs100.size() >= 2) _sumW_pt100_nch2 += weight;
        fillPtEtaNch(cfs100, 2, weight, _hist_pt100_nch2_nch, _hist_pt100_nch2_pt, _hist_pt100_nch2_eta, _hist_pt100_nch2_ptnch);
        // nch>=20
        if (cfs100.size() >= 20) _sumW_pt100_nch20 += weight;
        fillPtEtaNch(cfs100, 20, weight, _hist_pt100_nch20_nch, _hist_pt100_nch20_pt, _hist_pt100_nch20_eta);
      }

      // 500 GeV final states
      const ChargedFinalState& cfs500 = apply<ChargedFinalState>(event, "CFS500");
      // nch>=1
      if (cfs500.size() >= 1) _sumW_pt500_nch1 += weight;
      fillPtEtaNch(cfs500, 1, weight, _hist_pt500_nch1_nch, _hist_pt500_nch1_pt, _hist_pt500_nch1_eta, _hist_pt500_nch1_ptnch);
      // nch>=6
      if (!fuzzyEquals(sqrtS()/GeV, 2360)) {
        if (cfs500.size() >= 6) _sumW_pt500_nch6 += weight;
        fillPtEtaNch(cfs500, 6, weight, _hist_pt500_nch6_nch, _hist_pt500_nch6_pt, _hist_pt500_nch6_eta);
      }

      // 2500 GeV final states
      if (!fuzzyEquals(sqrtS()/GeV, 2360)) {
        const ChargedFinalState& cfs2500 = apply<ChargedFinalState>(event, "CFS2500");
        // nch>=1
        if (cfs2500.size() >= 1) _sumW_pt2500_nch1 += weight;
        fillPtEtaNch(cfs2500, 1, weight, _hist_pt2500_nch1_nch, _hist_pt2500_nch1_pt, _hist_pt2500_nch1_eta, _hist_pt2500_nch1_ptnch);
      }

    }



    void finalize() {

      if (!fuzzyEquals(sqrtS()/GeV, 2360)) {
        if (_sumW_pt100_nch2 > 0) {
          scale(_hist_pt100_nch2_nch, 1.0/_sumW_pt100_nch2);
          scale(_hist_pt100_nch2_pt, 1.0/_sumW_pt100_nch2/TWOPI/5);
          scale(_hist_pt100_nch2_eta, 1.0/_sumW_pt100_nch2);
        }

        if (_sumW_pt100_nch20 > 0) {
          scale(_hist_pt100_nch20_nch, 1.0/_sumW_pt100_nch20);
          scale(_hist_pt100_nch20_pt, 1.0/_sumW_pt100_nch20/TWOPI/5);
          scale(_hist_pt100_nch20_eta, 1.0/_sumW_pt100_nch20);
        }

        if (_sumW_pt500_nch6 > 0) {
          scale(_hist_pt500_nch6_nch, 1.0/_sumW_pt500_nch6);
          scale(_hist_pt500_nch6_pt, 1.0/_sumW_pt500_nch6/TWOPI/5);
          scale(_hist_pt500_nch6_eta, 1.0/_sumW_pt500_nch6);
        }

        if (_sumW_pt2500_nch1 > 0) {
          scale(_hist_pt2500_nch1_nch, 1.0/_sumW_pt2500_nch1);
          scale(_hist_pt2500_nch1_pt, 1.0/_sumW_pt2500_nch1/TWOPI/5);
          scale(_hist_pt2500_nch1_eta, 1.0/_sumW_pt2500_nch1);
        }
      }

      if (_sumW_pt500_nch1 > 0) {
        scale(_hist_pt500_nch1_nch, 1.0/_sumW_pt500_nch1);
        scale(_hist_pt500_nch1_pt, 1.0/_sumW_pt500_nch1/TWOPI/5);
        scale(_hist_pt500_nch1_eta, 1.0/_sumW_pt500_nch1);
      }
    }


  private:

    double _sumW_pt100_nch2, _sumW_pt100_nch20, _sumW_pt500_nch1,
      _sumW_pt500_nch6, _sumW_pt2500_nch1;

    Histo1DPtr _hist_pt100_nch2_nch,
      _hist_pt100_nch20_nch, _hist_pt500_nch1_nch,
      _hist_pt500_nch6_nch, _hist_pt2500_nch1_nch;

    Histo1DPtr _hist_pt100_nch2_pt,
      _hist_pt100_nch20_pt, _hist_pt500_nch1_pt,
      _hist_pt500_nch6_pt, _hist_pt2500_nch1_pt;

    Histo1DPtr _hist_pt100_nch2_eta,
      _hist_pt100_nch20_eta, _hist_pt500_nch1_eta,
      _hist_pt500_nch6_eta, _hist_pt2500_nch1_eta;

    Profile1DPtr _hist_pt100_nch2_ptnch,
      _hist_pt500_nch1_ptnch, _hist_pt2500_nch1_ptnch;

  };



  // The hook for the plugin system
  DECLARE_RIVET_PLUGIN(ATLAS_2010_S8918562);

}