Rivet analyses
title: ALICE_2021_I1862793
Prompt $\Xi_{c}^{0}$ and $\Xi_{c}^{+}$ analysis
Experiment: ALICE (LHC)
Inspire ID: 1862793
Status: VALIDATED
Authors: - Yonne Lourens
References: - Phys. Rev. Lett. 127 (2021) 272001 - DOI:10.1103/PhysRevLett.127.272001 - arXiv: 2105.05187 - Expt page: ALICE-7074
Beams: p+ p+
Beam energies: (6500.0, 6500.0)GeV
Run details: - Minimum bias events
The $p_\text{T}$-differential cross sections of prompt charm-strange baryons $\Xi^0_{c}$ and $\Xi^+{c}$ were measured at midrapidity ($|y| < 0.5$) in proton--proton (pp) collisions at a centre-of-mass energy $\sqrt{s}=$~13~TeV with the ALICE detector at the LHC. The $\Xi^0{c}$ baryon was reconstructed via both the semileptonic decay ($\Xi^{-}{e^{+}}\nu_{e}$) and the hadronic decay ($\Xi^{-}{\pi^{+}}$) channels. The $\Xi^+{c}$ baryon was reconstructed via the hadronic decay ($\Xi^{-}\pi^{+}\pi^{+}$) channel. The branching-fraction ratio ${BR}(\Xi_c^0\rightarrow \Xi^-e^+\nu_e)/{\rm BR}(\Xi_c^0\rightarrow \Xi^{-}\pi^+)=$ 1.38 $\pm$ 0.14 (stat) $\pm$ 0.22 (syst) was measured with a total uncertainty reduced by a factor of about 3 with respect to the current world average reported by the Particle Data Group. The transverse momentum ($p\text{T}$) dependence of the $\Xi^0_{c}$- and $\Xi^+{c}$-baryon production relative to the ${D^0}$-meson and to the $\Sigma^{0,+,++}{c}$- and $\Lambda^+{c}$-baryon production are reported. The baryon-to-meson ratio increases towards low $p\text{T}$ up to a value of approximately 0.3. The measurements are compared with various models that take different hadronisation mechanisms into consideration. The results provide stringent constraints to these theoretical calculations and additional evidence that different processes are involved in charm hadronisation in electron--positron ($e^+e^-$) and hadronic collisions.
Source code:ALICE_2021_I1862793.cc
```c++ // -- C++ --
include "Rivet/Analysis.hh"
include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief Prompt charm-strange baryons in pp at 13 TeV class ALICE_2021_I1862793 : public Analysis { public:
RIVET_DEFAULT_ANALYSIS_CTOR(ALICE_2021_I1862793);
void init() {
const UnstableParticles up(Cuts::absrap < 0.5);
declare(up, "up");
book(_h_X0, 1, 1, 1); // XiC0 production cross section
book(_h_XP, 2, 1, 1); // XiC+ production cross section
book(_h_X0D0, 3, 1, 1); // ratio of production cross section between XiC0 and D0
book(_h_XPDP, 4, 1, 1); // ratio of production cross section between XiC+ and D0
book(_h_X0Lc, 5, 1, 1); // ratio of production cross section between XiC and LambdaC
book(_h_XcSc, 6, 1, 1); // ratio of production cross section between XiC and SigmaC
book(_h_X0Iint, "TMP/Xint",
refData(7, 1, 1)); // XiC0 pt-integrated production cross section with 1<pt<12 GeV/c
book(_h_X0Oint, 8, 1, 1); // XiC0 pt-integrated production cross section with pt>0 GeV/c
book(_h_XPint, 9, 1, 1); // XiC+ pt-integrated production cross section with 4<pt<12 GeV/c
book(_h_X0D, "TMP/_h_X0D", refData(3, 1, 1)); // XiC0 production cross section
book(_h_D0, "TMP/_h_D0", refData(3, 1, 1)); // D0 production cross section
book(_h_DP, "TMP/_h_DP", refData(4, 1, 1)); // D0 production cross section
book(_h_XPD, "TMP/_h_XPD", refData(4, 1, 1)); // XiC+ production cross section
book(_h_Lc, "TMP/_h_Lc", refData(5, 1, 1)); // LambdaC production cross section
book(_h_X0L, "TMP/_h_X0L", refData(5, 1, 1)); // XiC0 production cross section
book(_h_Sc, "TMP/_h_Sc", refData(6, 1, 1)); // SigmaC production cross section
book(_h_Xc, "TMP/_h_Xc", refData(6, 1, 1)); // XiC production cross section
}
void analyze(const Event& event) {
if (_edges.empty()) _edges = _h_X0Oint->xEdges();
const UnstableParticles& up = apply<UnstableParticles>(event, "up");
for (const Particle& p : up.particles()) {
if (p.fromBottom())
continue;
else {
if (p.abspid() == 4222 || p.abspid() == 4212 || p.abspid() == 4112) {
_h_Sc->fill(p.pT() / GeV);
}
else if (p.abspid() == 4122) {
_h_Lc->fill(p.pT() / GeV);
}
else if (p.abspid() == 421) {
_h_D0->fill(p.pT() / GeV);
_h_DP->fill(p.pT() / GeV);
}
else if (p.abspid() == 4132) {
_h_X0->fill(p.pT() / GeV);
_h_X0D->fill(p.pT() / GeV);
_h_Xc->fill(p.pT() / GeV);
_h_X0L->fill(p.pT() / GeV);
_h_X0Oint->fill(_edges[0]);
if (p.pT() / GeV < 12.0 && p.pT() / GeV >= 1.0) {
_h_X0Iint->fill(1);
}
}
else if (p.abspid() == 4232) {
_h_XP->fill(p.pT() / GeV);
_h_Xc->fill(p.pT() / GeV);
_h_XPD->fill(p.pT() / GeV);
if (p.pT() / GeV < 12.0 && p.pT() / GeV >= 4.0) {
_h_XPint->fill(8);
}
}
}
}
}
void finalize() {
scale(_h_Sc, crossSection() / (microbarn * 2 * sumOfWeights()));
scale(_h_Lc, crossSection() / (microbarn * 2 * sumOfWeights()));
scale(_h_D0, crossSection() / (microbarn * 2 * sumOfWeights()));
scale(_h_DP, crossSection() / (microbarn * 2 * sumOfWeights()));
scale(_h_Xc, crossSection() / (microbarn * 2 * sumOfWeights()));
scale(_h_X0, crossSection() / (microbarn * 2 * sumOfWeights()));
scale(_h_XP, crossSection() / (microbarn * 2 * sumOfWeights()));
scale(_h_X0D, crossSection() / (microbarn * 2 * sumOfWeights()));
scale(_h_XPD, crossSection() / (microbarn * 2 * sumOfWeights()));
scale(_h_X0L, crossSection() / (microbarn * 2 * sumOfWeights()));
divide(_h_X0D, _h_D0, _h_X0D0);
divide(_h_XPD, _h_DP, _h_XPDP);
divide(_h_X0L, _h_Lc, _h_X0Lc);
divide(_h_Xc, _h_Sc, _h_XcSc);
scale(_h_X0Iint, crossSection() / (microbarn * 2 * sumOfWeights()));
Estimate1DPtr tmp;
book(tmp, 7, 1, 1);
barchart(_h_X0Iint, tmp);
scale(_h_X0Oint, crossSection() / (microbarn * 2 * sumOfWeights()));
scale(_h_XPint, crossSection() / (microbarn * 2 * sumOfWeights()));
}
Histo1DPtr _h_X0, _h_XP, _h_X0Iint, _h_XPint, _h_Sc, _h_Lc, _h_D0, _h_DP, _h_Xc, _h_X0D, _h_XPD, _h_X0L;
Estimate1DPtr _h_X0D0, _h_XPDP, _h_X0Lc, _h_XcSc;
BinnedHistoPtr<string> _h_X0Oint;
vector<string> _edges;
};
RIVET_DECLARE_PLUGIN(ALICE_2021_I1862793);
} ```