Rivet analyses

title: E735_1998_I480349

Charged particle multiplicity in $p\bar{p}$ collisions at $\sqrt{s} = 1.8~\TeV$

Experiment: E735 (Tevatron)

Inspire ID: 480349

Status: VALIDATED

Authors: - Holger Schulz - Andy Buckley

References: - Phys.Lett.B435:453-457,1998

Beams: p- p+

Beam energies: (900.0, 900.0)GeV

Run details: - QCD events, diffractive processes need to be switched on in order to fill the low multiplicity regions. The measurement was done in $|\eta| \lesssim 3.25$ and was extrapolated to full phase space. However, the method of extrapolation remains unclear.

A measurement of the charged multiplicity distribution at $\sqrt{s} = 1.8~\TeV$. The analysis is reproduced to the best of abilities. There is no theory curve in the paper to compare to.

Source code:E735_1998_I480349.cc

```c++ // -- C++ --

include "Rivet/Analysis.hh"

include "Rivet/Projections/ChargedFinalState.hh"

include "Rivet/Projections/TriggerCDFRun0Run1.hh"

include "Rivet/Projections/TriggerUA5.hh"

namespace Rivet {

/// @brief E735 charged multiplicity in NSD-triggered events class E735_1998_I480349 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(E735_1998_I480349);


/// @name Analysis methods
/// @{

void init() {
  // Projections
  declare(TriggerUA5(), "Trigger");
  declare(ChargedFinalState(), "FS");

  // Histo
  book(_hist_multiplicity, 1, 1, 1);
  book(_sumWTrig, "TMP/sumWtrig");
}


void analyze(const Event& event) {
  const bool trigger = apply<TriggerUA5>(event, "Trigger").nsdDecision();
  if (!trigger) vetoEvent;
  _sumWTrig->fill();

  const ChargedFinalState& fs = apply<ChargedFinalState>(event, "FS");
  const size_t numParticles = fs.particles().size();
  _hist_multiplicity->fill(numParticles);
}


void finalize() {
  scale(_hist_multiplicity, 1 / *_sumWTrig);
}

/// @}

private:

/// Weight counter
CounterPtr _sumWTrig;

/// Histograms
Histo1DPtr _hist_multiplicity;

};

RIVET_DECLARE_ALIASED_PLUGIN(E735_1998_I480349, E735_1998_S3905616);

} ```

Aliases: - E735_1998_S3905616