rivet is hosted by Hepforge, IPPP Durham

## Rivet analyses reference

### NA22_1986_I18431

Multiplicity distributions in $pp$, $K^+ p$ and $\pi^+ p$ at $p_{\mathrm{lab}} = 250$ GeV/c
Experiment: NA22 (SPS)
Inspire ID: 18431
Status: VALIDATED
Authors:
• Christian Bierlich
References:
• Z.Phys. C32 (1986) 475
Beams: p+ p+, 321 p+, 211 p+
Beam energies: (250.0, 0.0); (250.0, 0.0); (250.0, 0.0) GeV
Run details:
• Fixed target events with $p$, $K^+$ and $\pi^+$ hitting a proton target.

Charged multiplicity distributions of $pp$, $K^+ p$ and $\pi^+ p$ fixed target collisions, $p_{\mathrm{lab}} = 250$ GeV/c or equivalently $\sqrt{s} = 21.7$ GeV/c (pp).

Source code: NA22_1986_I18431.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 // -*- C++ -*- #include "Rivet/Analysis.hh" #include "Rivet/Projections/Beam.hh" #include "Rivet/Projections/ChargedFinalState.hh" namespace Rivet { /// @brief NA22 min bias multiplicity distributions. class NA22_1986_I18431 : public Analysis { public: /// Constructor DEFAULT_RIVET_ANALYSIS_CTOR(NA22_1986_I18431); /// @name Analysis methods //@{ /// Book histograms and initialise projections before the run void init() { declare(ChargedFinalState(), "CFS"); // Figure out beam type const ParticlePair& beam = beams(); int btype = 0; if (beam.first.pid() == PID::PIPLUS && beam.second.pid() == PID::PROTON) btype = 1; else if (beam.first.pid() == PID::KPLUS && beam.second.pid() == PID::PROTON) btype = 2; else if (beam.first.pid() == PID::PROTON && beam.second.pid() == PID::PROTON) btype = 3; else { MSG_ERROR("Beam error: Not compatible!"); return; } book(_h_mult, btype, 1, 1); } /// Perform the per-event analysis void analyze(const Event& event) { int nfs = apply(event, "CFS").size(); _h_mult->fill(nfs); } /// Normalise histograms etc., after the run void finalize() { normalize(_h_mult); // normalize to unity } //@} /// @name Histograms //@{ Histo1DPtr _h_mult; //@} }; // The hook for the plugin system DECLARE_RIVET_PLUGIN(NA22_1986_I18431); }