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## Rivet analyses reference

### ALICE_2012_I944757

Measurement of charm production at central rapidity in proton-proton collisions at $\sqrt{s}=7$ TeV
Experiment: ALICE (LHC)
Inspire ID: 944757
Status: VALIDATED
Authors:
• Marco Giacalone
References: Beams: p+ p+
Beam energies: (3500.0, 3500.0) GeV
Run details:
• Proton Proton events at 7 TeV simulated using PYTHIA 8.240 and HERWIG 7.1.5. SoftQCD:all parameter enabled on the former, while MB (Minimum Bias) and SoftTune snippets were used for the latter.

The $p_\text{T}$-differential inclusive production cross sections of the prompt charmed mesons $D^0$, $D^+$, and $D^{\ast +}$ in the rapidity range $|y|<0.5$ were measured in proton-proton collisions at $\sqrt{s}=7$ TeV at the LHC using the ALICE detector. Reconstructing the decays $D^0 \to K^-\pi^+$, $D^+\to K^-\pi^+\pi^+$, $D^{\ast +} \to D^0\pi^+$, and their charge conjugates, about 8,400 $D^0$, 2,900 $D^+$, and 2,600 $D^{\ast +}$ mesons with $1 < p_\text{T} < 24$ GeV/$c$ were counted, after selection cuts, in a data sample of 3.14$\times 10^8$ events collected with a minimum-bias trigger (integrated luminosity $L_\text{int} = 5$/nb). The results are described within uncertainties by predictions based on perturbative QCD.

Source code: ALICE_2012_I944757.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 #include "Rivet/Analysis.hh" #include "Rivet/Projections/UnstableParticles.hh" namespace Rivet { /// @brief Charm production at central rapidity in pp at 7 TeV class ALICE_2012_I944757 : public Analysis { public: /// Constructor DEFAULT_RIVET_ANALYSIS_CTOR(ALICE_2012_I944757); /// @name Analysis methods //@{ /// Book histograms and initialise projections before the run void init() { // Initialise and register projections declare(UnstableParticles(Cuts::absrap < 0.5), "UFS"); // Book histograms book(_h_D0, 1, 1, 1); book(_h_Dplus, 2, 1, 1); book(_h_Dstarp, 3, 1, 1); book(_h_integ, 4, 1, 1); } /// Perform the per-event analysis void analyze(const Event& event) { /*PDG code IDs used inside the for loop: 421 = D0, 411 = D+, 413 = D*+ */ for (const Particle& p : apply(event, "UFS").particles()) { if (p.fromBottom()) continue; if (p.abspid() == 421) { _h_D0->fill(p.pT()/GeV); _h_integ->fill(1); } else if (p.abspid() == 411) { _h_Dplus->fill(p.pT()/GeV); _h_integ->fill(2); } else if (p.abspid()== 413) { _h_Dstarp->fill(p.pT()/GeV); _h_integ->fill(3); } } } /// Normalise histograms etc., after the run void finalize() { scale(_h_D0, crossSection()/(microbarn*2*sumOfWeights())); // norm to cross section scale(_h_Dplus, crossSection()/(microbarn*2*sumOfWeights())); // norm to cross section scale(_h_Dstarp, crossSection()/(microbarn*2*sumOfWeights())); // norm to cross section scale(_h_integ, crossSection()/(microbarn*2*sumOfWeights())); // norm to cross section /* Obtained cross sections data at this point consider both particles and antiparticles hence the added factor 2 in the normalization solves the issue (as done in the paper) */ } //@} /// @name Histograms //@{ Histo1DPtr _h_D0, _h_Dplus, _h_Dstarp, _h_integ; //@} }; // The hook for the plugin system DECLARE_RIVET_PLUGIN(ALICE_2012_I944757); }