Rivet analyses

title: LHCB_2011_I917009

$V^0$ production ratios in $pp$ collisions at $\sqrt{s}= 0.9$ and 7 TeV at LHCb

Experiment: LHCb (LHC)

Inspire ID: 917009

Status: VALIDATED

Authors: - Alex Grecu

References: - JHEP08:034,2011 - arXiv: 1107.0882 - DOI: 10.1007/JHEP08(2011)034

Beams: p+ p+

Beam energies: (450.0, 450.0); (3500.0, 3500.0)GeV

Run details: - QCD events. LHCb minimum bias, Perugia 0 and Perugia NOCR tune events used for reproducing published histograms.

This paper presents the production ratios for $\bar{\Lambda}/\Lambda$ and $\bar{\Lambda}/K_{s}^{0}$ measured by LHCb detector in 2010 at $\sqrt{s} = 0.9$ TeV and 7 TeV as functions of the transverse momentum $p_\perp$ and the rapidity $y$ in the ranges $0.15 < p_\perp < 2.50~\GeV/c$ and $2.0 < y < 4.5$, respectively. The results for the two energies are merged and represented as a function of rapidity loss $\Delta y = y_{\mathrm{beam}} - y$.

Source code:LHCB_2011_I917009.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief V0 production ratios at 0.9 and 7 TeV class LHCB_2011_I917009 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(LHCB_2011_I917009);

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

/// Book histograms and initialise projections before the run
void init() {
  fillMap(partLftMap);

  for (double eVal : allowedEnergies()) {
    const int en = round(eVal);
    if (isCompatibleWithSqrtS(eVal)) _sqs = en;

    rap_beam = (en == 900) ? 6.87 : 8.92;
    rap_max = (en == 900) ? 4. : 4.5;
    bool is7TeV = en == 7000;

    // Create the sets of temporary histograms that will be used to make the ratios in the finalize()
    for (size_t i = 0; i < 12; ++i) {
      book(_h[en + i], "TMP/" + to_str(en + i), 4 + is7TeV, 2.0, rap_max);
    }
    for (size_t i = 12; i < 15; ++i) {
      book(_h[en + i], "TMP/" + to_str(en + i), refData(8 * is7TeV + 5, 1, 1));
    }
    for (size_t i = 15; i < 18; ++i) {
      book(_h[en + i], "TMP/" + to_str(en + i), 4 + is7TeV, rap_beam - rap_max, rap_beam - 2.0);
    }

    int dsId = 8 * is7TeV + 1;
    for (size_t j = 0; j < 3; ++j) {
      book(_s[en + 10 + j], dsId, 1, j + 1);
      book(_s[en + 20 + j], dsId + 1, 1, j + 1);
    }
    dsId += 2;
    for (size_t j = 3; j < 6; ++j) {
      book(_s[en + 30 + j - 3], dsId, 1, 1);
      dsId += 1;
      book(_s[en + 40 + j - 3], dsId, 1, 1);
      dsId += 1;
    }
  }
  raiseBeamErrorIf(_sqs == 0);

  if (_sqs == 900) {
    rap_beam = 6.87;
    rap_max = 4.;
    pt_min = 0.25;
  }
  else {
    rap_beam = 8.92;
    rap_max = 4.5;
    pt_min = 0.15;
  }

  declare(UnstableParticles(), "UFS");
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
  double ancestor_lftsum = 0.0;
  double y, pT;
  int id;
  int partIdx = -1;
  for (const Particle& p : ufs.particles()) {
    id = p.pid();
    // continue if particle not a K0s nor (anti-)Lambda
    if ((id == 310) || (id == -310)) {
      partIdx = 2;
    }
    else if (id == 3122) {
      partIdx = 1;
    }
    else if (id == -3122) {
      partIdx = 0;
    }
    else {
      continue;
    }
    ancestor_lftsum = getMotherLifeTimeSum(p);
    // Lifetime cut: ctau sum of all particle ancestors < 10^-9 m according to the paper (see eq. 5)
    const double MAX_CTAU = 1.0E-9; // [m]
    if ((ancestor_lftsum < 0.0) || (ancestor_lftsum > MAX_CTAU)) continue;
    const FourMomentum& qmom = p.momentum();
    y = log((qmom.E() + qmom.pz()) / (qmom.E() - qmom.pz())) / 2.;
    // skip this particle if it has too high or too low rapidity (extremely rare cases when E = +- pz)
    if (std::isnan(y) || std::isinf(y)) continue;
    y = fabs(y);
    if (!inRange(y, 2.0, rap_max)) continue;
    pT = sqrt((qmom.px() * qmom.px()) + (qmom.py() * qmom.py()));
    if (!inRange(pT, pt_min, 2.5)) continue;
    // Filling corresponding temporary histograms for pT intervals
    if (inRange(pT, pt_min, 0.65)) _h[_sqs + partIdx * 3]->fill(y);
    if (inRange(pT, 0.65, 1.0)) _h[_sqs + partIdx * 3 + 1]->fill(y);
    if (inRange(pT, 1.0, 2.5)) _h[_sqs + partIdx * 3 + 2]->fill(y);
    // Fill histo in rapidity for whole pT interval
    _h[_sqs + partIdx + 9]->fill(y);
    // Fill histo in pT for whole rapidity interval
    _h[_sqs + partIdx + 12]->fill(pT);
    // Fill histo in rapidity loss for whole pT interval
    _h[_sqs + partIdx + 15]->fill(rap_beam - y);
  }
}


// Generate the ratio histograms
void finalize() {
  for (double eVal : allowedEnergies()) {
    const int en = round(eVal);
    for (size_t j = 0; j < 3; ++j) {
      divide(_h[en + j], _h[en + 3 + j], _s[en + 10 + j]);
      divide(_h[en + j], _h[en + 6 + j], _s[en + 20 + j]);
      divide(_h[en + 3 * (j + 3)], _h[en + 3 * (j + 3) + 1], _s[en + 30 + j]);
      divide(_h[en + 3 * (j + 3)], _h[en + 3 * (j + 3) + 2], _s[en + 40 + j]);
    }
  }
}

/// @}

// Get particle lifetime from hardcoded data
double getLifeTime(int pid) {
  double lft = -1.0;
  if (pid < 0) pid = -pid;
  // Correct Pythia6 PIDs for f0(980), f0(1370) mesons
  if (pid == 10331) pid = 30221;
  if (pid == 10221) pid = 9010221;
  map<int, double>::iterator pPartLft = partLftMap.find(pid);
  // search stable particle list
  if (pPartLft == partLftMap.end()) {
    if (pid <= 100) return 0.0;
    for (size_t i = 0; i < sizeof(stablePDGIds) / sizeof(unsigned int); i++) {
      if (pid == stablePDGIds[i]) {
        lft = 0.0;
        break;
      }
    }
  }
  else {
    lft = (*pPartLft).second;
  }
  if (lft < 0.0 && PID::isHadron(pid)) {
    MSG_ERROR("Could not determine lifetime for particle with PID "
              << pid << "... This V^0 will be considered unprompt!");
  }
  return lft;
}

// Data members like post-cuts event weight counters go here
double getMotherLifeTimeSum(const Particle& p) {
  if (p.genParticle() == nullptr) return -1.;
  double lftSum = 0.;
  double plft = 0.;
  ConstGenParticlePtr part = p.genParticle();
  ConstGenVertexPtr ivtx = part->production_vertex();
  while (ivtx) {

    vector<ConstGenParticlePtr> part_in = HepMCUtils::particles(ivtx, Relatives::PARENTS);

    if (part_in.size() < 1) {
      lftSum = -1.;
      break;
    };
    ConstGenParticlePtr part = part_in.at(0); //(*iPart_invtx);
    if (!(part)) {
      lftSum = -1.;
      break;
    };
    ivtx = part->production_vertex();
    if ((part->pdg_id() == 2212) || !(ivtx)) break; //reached beam
    plft = getLifeTime(part->pdg_id());
    if (plft < 0.) {
      lftSum = -1.;
      break;
    };
    lftSum += plft;
  };
  return (lftSum * c_light);
}

private:

/// @name Private variables
/// @{

// The rapidity of the beam according to the selected beam energy
double rap_beam;

// The edges of the intervals of transverse momentum
double pt_min;

// The limits of the rapidity window
double rap_max;

// Map between PDG id and particle lifetimes in seconds
map<int, double> partLftMap;

// Set of PDG Ids for stable particles (PDG Id <= 100 are considered stable)
static const int stablePDGIds[205];

size_t _sqs = 0;

/// @}

/// @name Helper histograms
/// @{
/// Histograms are defined in the following order: anti-Lambda, Lambda and K0s.
/// First 3 suites of 3 histograms correspond to each particle in bins of y for the 3 pT intervals. (9 histos)
/// Next 3 histograms contain the particles in y bins for the whole pT interval (3 histos)
/// Next 3 histograms contain the particles in y_loss bins for the whole pT interval (3 histos)
/// Last 3 histograms contain the particles in pT bins for the whole rapidity (y) interval (3 histos)
map<size_t, Histo1DPtr> _h;
map<size_t, Estimate1DPtr> _s;
/// @}

// Fill the PDG ID to Lifetime[seconds] map
// Data was extracted from LHCb Particle Table through LHCb::ParticlePropertySvc
bool fillMap(map<int, double>& m) {
  m[6] = 4.707703E-25;
  m[11] = 1.E+16;
  m[12] = 1.E+16;
  m[13] = 2.197019E-06;
  m[14] = 1.E+16;
  m[15] = 2.906E-13;
  m[16] = 1.E+16;
  m[22] = 1.E+16;
  m[23] = 2.637914E-25;
  m[24] = 3.075758E-25;
  m[25] = 9.4E-26;
  m[35] = 9.4E-26;
  m[36] = 9.4E-26;
  m[37] = 9.4E-26;
  m[84] = 3.335641E-13;
  m[85] = 1.290893E-12;
  m[111] = 8.4E-17;
  m[113] = 4.405704E-24;
  m[115] = 6.151516E-24;
  m[117] = 4.088275E-24;
  m[119] = 2.102914E-24;
  m[130] = 5.116E-08;
  m[150] = 1.525E-12;
  m[211] = 2.6033E-08;
  m[213] = 4.405704E-24;
  m[215] = 6.151516E-24;
  m[217] = 4.088275E-24;
  m[219] = 2.102914E-24;
  m[221] = 5.063171E-19;
  m[223] = 7.752794E-23;
  m[225] = 3.555982E-24;
  m[227] = 3.91793E-24;
  m[229] = 2.777267E-24;
  m[310] = 8.953E-11;
  m[313] = 1.308573E-23;
  m[315] = 6.038644E-24;
  m[317] = 4.139699E-24;
  m[319] = 3.324304E-24;
  m[321] = 1.238E-08;
  m[323] = 1.295693E-23;
  m[325] = 6.682357E-24;
  m[327] = 4.139699E-24;
  m[329] = 3.324304E-24;
  m[331] = 3.210791E-21;
  m[333] = 1.545099E-22;
  m[335] = 9.016605E-24;
  m[337] = 7.565657E-24;
  m[350] = 1.407125E-12;
  m[411] = 1.04E-12;
  m[413] = 6.856377E-21;
  m[415] = 1.778952E-23;
  m[421] = 4.101E-13;
  m[423] = 1.000003E-19;
  m[425] = 1.530726E-23;
  m[431] = 5.E-13;
  m[433] = 1.000003E-19;
  m[435] = 3.291061E-23;
  m[441] = 2.465214E-23;
  m[443] = 7.062363E-21;
  m[445] = 3.242425E-22;
  m[510] = 1.525E-12;
  m[511] = 1.525E-12;
  m[513] = 1.000019E-19;
  m[515] = 1.31E-23;
  m[521] = 1.638E-12;
  m[523] = 1.000019E-19;
  m[525] = 1.31E-23;
  m[530] = 1.536875E-12;
  m[531] = 1.472E-12;
  m[533] = 1.E-19;
  m[535] = 1.31E-23;
  m[541] = 4.5E-13;
  m[553] = 1.218911E-20;
  m[1112] = 4.539394E-24;
  m[1114] = 5.578069E-24;
  m[1116] = 1.994582E-24;
  m[1118] = 2.269697E-24;
  m[1212] = 4.539394E-24;
  m[1214] = 5.723584E-24;
  m[1216] = 1.994582E-24;
  m[1218] = 1.316424E-24;
  m[2112] = 8.857E+02;
  m[2114] = 5.578069E-24;
  m[2116] = 4.388081E-24;
  m[2118] = 2.269697E-24;
  m[2122] = 4.539394E-24;
  m[2124] = 5.723584E-24;
  m[2126] = 1.994582E-24;
  m[2128] = 1.316424E-24;
  m[2212] = 1.E+16;
  m[2214] = 5.578069E-24;
  m[2216] = 4.388081E-24;
  m[2218] = 2.269697E-24;
  m[2222] = 4.539394E-24;
  m[2224] = 5.578069E-24;
  m[2226] = 1.994582E-24;
  m[2228] = 2.269697E-24;
  m[3112] = 1.479E-10;
  m[3114] = 1.670589E-23;
  m[3116] = 5.485102E-24;
  m[3118] = 3.656734E-24;
  m[3122] = 2.631E-10;
  m[102134] = 4.219309E-23;
  m[3126] = 8.227653E-24;
  m[3128] = 3.291061E-24;
  m[3212] = 7.4E-20;
  m[3214] = 1.828367E-23;
  m[3216] = 5.485102E-24;
  m[3218] = 3.656734E-24;
  m[3222] = 8.018E-11;
  m[3224] = 1.838582E-23;
  m[3226] = 5.485102E-24;
  m[3228] = 3.656734E-24;
  m[3312] = 1.639E-10;
  m[3314] = 6.648608E-23;
  m[3322] = 2.9E-10;
  m[3324] = 7.233101E-23;
  m[3334] = 8.21E-11;
  m[4112] = 2.991874E-22;
  m[4114] = 4.088274E-23;
  m[4122] = 2.E-13;
  m[4132] = 1.12E-13;
  m[4212] = 3.999999E-22;
  m[4214] = 3.291061E-22;
  m[4222] = 2.951624E-22;
  m[4224] = 4.417531E-23;
  m[4232] = 4.42E-13;
  m[4332] = 6.9E-14;
  m[4412] = 3.335641E-13;
  m[4422] = 3.335641E-13;
  m[4432] = 3.335641E-13;
  m[5112] = 1.E-19;
  m[5122] = 1.38E-12;
  m[5132] = 1.42E-12;
  m[5142] = 1.290893E-12;
  m[5212] = 1.E-19;
  m[5222] = 1.E-19;
  m[5232] = 1.42E-12;
  m[5242] = 1.290893E-12;
  m[5312] = 1.E-19;
  m[5322] = 1.E-19;
  m[5332] = 1.55E-12;
  m[5342] = 1.290893E-12;
  m[5442] = 1.290893E-12;
  m[5512] = 1.290893E-12;
  m[5522] = 1.290893E-12;
  m[5532] = 1.290893E-12;
  m[5542] = 1.290893E-12;
  m[10111] = 2.48382E-24;
  m[10113] = 4.635297E-24;
  m[10115] = 2.54136E-24;
  m[10211] = 2.48382E-24;
  m[10213] = 4.635297E-24;
  m[10215] = 2.54136E-24;
  m[10223] = 1.828367E-24;
  m[10225] = 3.636531E-24;
  m[10311] = 2.437823E-24;
  m[10313] = 7.313469E-24;
  m[10315] = 3.538775E-24;
  m[10321] = 2.437823E-24;
  m[10323] = 7.313469E-24;
  m[10325] = 3.538775E-24;
  m[10331] = 4.804469E-24;
  m[10411] = 4.38E-24;
  m[10413] = 3.29E-23;
  m[10421] = 4.38E-24;
  m[10423] = 3.22653E-23;
  m[10431] = 6.5821E-22;
  m[10433] = 6.5821E-22;
  m[10441] = 6.453061E-23;
  m[10511] = 4.39E-24;
  m[10513] = 1.65E-23;
  m[10521] = 4.39E-24;
  m[10523] = 1.65E-23;
  m[10531] = 4.39E-24;
  m[10533] = 1.65E-23;
  m[11114] = 2.194041E-24;
  m[11116] = 1.828367E-24;
  m[11212] = 1.880606E-24;
  m[11216] = 1.828367E-24;
  m[12112] = 2.194041E-24;
  m[12114] = 2.194041E-24;
  m[12116] = 5.063171E-24;
  m[12126] = 1.828367E-24;
  m[12212] = 2.194041E-24;
  m[12214] = 2.194041E-24;
  m[12216] = 5.063171E-24;
  m[12224] = 2.194041E-24;
  m[12226] = 1.828367E-24;
  m[13112] = 6.582122E-24;
  m[13114] = 1.09702E-23;
  m[13116] = 5.485102E-24;
  m[13122] = 1.316424E-23;
  m[13124] = 1.09702E-23;
  m[13126] = 6.928549E-24;
  m[13212] = 6.582122E-24;
  m[13214] = 1.09702E-23;
  m[13216] = 5.485102E-24;
  m[13222] = 6.582122E-24;
  m[13224] = 1.09702E-23;
  m[13226] = 5.485102E-24;
  m[13314] = 2.742551E-23;
  m[13324] = 2.742551E-23;
  m[102142] = 1.828367E-22;
  m[20022] = 1.E+16;
  m[20113] = 1.567172E-24;
  m[20213] = 1.567172E-24;
  m[20223] = 2.708692E-23;
  m[20313] = 3.782829E-24;
  m[20315] = 2.384827E-24;
  m[20323] = 3.782829E-24;
  m[20325] = 2.384827E-24;
  m[20333] = 1.198929E-23;
  m[20413] = 2.63E-24;
  m[20423] = 2.63E-24;
  m[20433] = 6.5821E-22;
  m[20443] = 7.395643E-22;
  m[20513] = 2.63E-24;
  m[20523] = 2.63E-24;
  m[20533] = 2.63E-24;
  m[21112] = 2.632849E-24;
  m[21114] = 3.291061E-24;
  m[21212] = 2.632849E-24;
  m[21214] = 6.582122E-24;
  m[22112] = 4.388081E-24;
  m[22114] = 3.291061E-24;
  m[22122] = 2.632849E-24;
  m[22124] = 6.582122E-24;
  m[22212] = 4.388081E-24;
  m[22214] = 3.291061E-24;
  m[22222] = 2.632849E-24;
  m[22224] = 3.291061E-24;
  m[23112] = 7.313469E-24;
  m[23114] = 2.991874E-24;
  m[23122] = 4.388081E-24;
  m[23124] = 6.582122E-24;
  m[23126] = 3.291061E-24;
  m[23212] = 7.313469E-24;
  m[23214] = 2.991874E-24;
  m[23222] = 7.313469E-24;
  m[23224] = 2.991874E-24;
  m[30113] = 2.632849E-24;
  m[30213] = 2.632849E-24;
  m[30221] = 1.880606E-24;
  m[30223] = 2.089563E-24;
  m[30313] = 2.056913E-24;
  m[30323] = 2.056913E-24;
  m[30443] = 2.419898E-23;
  m[31114] = 1.880606E-24;
  m[31214] = 3.291061E-24;
  m[32112] = 3.989164E-24;
  m[32114] = 1.880606E-24;
  m[32124] = 3.291061E-24;
  m[32212] = 3.989164E-24;
  m[32214] = 1.880606E-24;
  m[32224] = 1.880606E-24;
  m[33122] = 1.880606E-23;
  m[42112] = 6.582122E-24;
  m[42212] = 6.582122E-24;
  m[43122] = 2.194041E-24;
  m[53122] = 4.388081E-24;
  m[100111] = 1.645531E-24;
  m[100113] = 1.64553E-24;
  m[100211] = 1.645531E-24;
  m[100213] = 1.64553E-24;
  m[100221] = 1.196749E-23;
  m[100223] = 3.061452E-24;
  m[100313] = 2.837122E-24;
  m[100323] = 2.837122E-24;
  m[100331] = 4.459432E-25;
  m[100333] = 4.388081E-24;
  m[100441] = 4.701516E-23;
  m[100443] = 2.076379E-21;
  m[100553] = 2.056913E-20;
  m[200553] = 3.242425E-20;
  m[300553] = 3.210791E-23;
  m[9000111] = 8.776163E-24;
  m[9000211] = 8.776163E-24;
  m[9000443] = 8.227652E-24;
  m[9000553] = 5.983747E-24;
  m[9010111] = 3.164482E-24;
  m[9010211] = 3.164482E-24;
  m[9010221] = 9.403031E-24;
  m[9010443] = 8.438618E-24;
  m[9010553] = 8.3318E-24;
  m[9020443] = 1.061633E-23;
  m[9030221] = 6.038644E-24;
  m[9042413] = 2.07634E-21;
  m[9050225] = 1.394517E-24;
  m[9060225] = 3.291061E-24;
  m[9080225] = 4.388081E-24;
  m[9090225] = 2.056913E-24;
  m[9910445] = 2.07634E-21;
  m[9920443] = 2.07634E-21;
  return true;
}

};

const int LHCB_2011_I917009::stablePDGIds[205] = { 311, 543, 545, 551, 555, 557, 1103, 2101, 2103, 2203, 3101, 3103, 3201, 3203, 3303, 4101, 4103, 102144, 4201, 4203, 4301, 4303, 4312, 4314, 4322, 4324, 4334, 4403, 4414, 4424, 4434, 4444, 5101, 5103, 5114, 5201, 5203, 5214, 5224, 5301, 5303, 5314, 5324, 5334, 5401, 5403, 5412, 5414, 5422, 5424, 5432, 5434, 5444, 5503, 5514, 5524, 5534, 5544, 5554, 10022, 10333, 10335, 10443, 10541, 10543, 10551, 10553, 10555, 11112, 12118, 12122, 12218, 12222, 13316, 13326, 20543, 20553, 20555, 23314, 23324, 30343, 30353, 30363, 30553, 33314, 33324, 41214, 42124, 52114, 52214, 100311, 100315, 100321, 100325, 100411, 100413, 100421, 100423, 100551, 100555, 100557, 110551, 110553, 110555, 120553, 120555, 130553, 200551, 200555, 210551, 210553, 220553, 1000001, 1000002, 1000003, 1000004, 1000005, 1000006, 1000011, 1000012, 1000013, 1000014, 1000015, 1000016, 1000021, 1000022, 1000023, 1000024, 1000025, 1000035, 1000037, 1000039, 2000001, 2000002, 2000003, 2000004, 2000005, 2000006, 2000011, 2000012, 2000013, 2000014, 2000015, 2000016, 3000111, 3000113, 3000211, 3000213, 3000221, 3000223, 3000331, 3100021, 3100111, 3100113, 3200111, 3200113, 3300113, 3400113, 4000001, 4000002, 4000011, 4000012, 5000039, 9000221, 9900012, 9900014, 9900016, 9900023, 9900024, 9900041, 9900042};

RIVET_DECLARE_PLUGIN(LHCB_2011_I917009);

} ```