Charm-quark fragmentation fractions and production cross section at midrapidity in pp collisions at the LHC

Abstract

Recent $p_{\mathrm{T}}$-integrated cross section measurements of the ground-state charm mesons and baryons, D${}^0$, D${}^{+}$, D${}_{\mathrm{s}}^{+}$, ${\Lambda }_{\mathrm{c}}^{+}$, and ${\Xi }_{\mathrm{c}}^0$, are used to evaluate the charm fragmentation fractions and production cross section per unit of rapidity at midrapidity ($|y|<0.5$), in pp collisions at $\sqrt{s}=5.02$ TeV at the LHC. The latter is $\mathrm{d}{\sigma }^{\mathrm{c}\overline{\mathrm{c}}}/\mathrm{d}y{|}_{|y|<0.5}$ =1165 $\pm 44(\mathrm{stat}{)}_{-101}^{+134}(\mathrm{syst})$ $\mu b$. These measurements were obtained for the first time in hadronic collisions at the LHC including the charm baryon states, recently measured by ALICE at midrapidity. The charm fragmentation fractions differ significantly from the values measured in e${}^{+}$e${}^{-}$ and ep collisions, providing evidence of the dependence of the parton-to-hadron fragmentation fractions on the collision system, indicating that the assumption of their universality is not supported by the measured cross sections. An increase of a factor of about 3.3 for the fragmentation fraction for the ${\Lambda }_{\mathrm{c}}^{+}$ with a significance of $5\sigma$ between the values obtained in pp collisions and those obtained in e${}^{+}$e${}^{-}$ (ep) collisions is reported. The fragmentation fraction for the ${\Xi }_{\mathrm{c}}^0$ was obtained for the first time in any collision system. The measured fragmentation fractions were used to update the $\mathrm{c}\overline{\mathrm{c}}$ cross sections per unit of rapidity at $|y|<0.5$ at $\sqrt{s}=2.76$ and 7 TeV, which are about 40% higher than the previously published results. The data were compared with perturbative-QCD calculations and lie at the upper edge of the theoretical bands.

arXiv comment20 pages, 2 captioned figures, 1 table, authors from page 14, published version, figures at https://alice-publications.web.cern.ch/node/7107

References in corpus (62)

• New parton distributions for collider physics
• New parton distribution functions from a global analysis of quantum chromodynamics
• The total top quark pair production cross-section at hadron colliders through O(alpha_S^4)
• Implications of CTEQ global analysis for collider observables
• A Positive-Weight Next-to-Leading-Order Monte Carlo for Heavy Flavour Hadroproduction
• Tuning PYTHIA 8.1: the Monash 2013 Tune
• Performance of the ALICE Experiment at the CERN LHC
• The p_T Spectrum in Heavy-Flavour Hadroproduction
• New CTEQ global analysis of quantum chromodynamics with high-precision data from the LHC
• Decoding the phase structure of QCD via particle production at high energy
• Theoretical predictions for charm and bottom production at the LHC
• (Non)Thermal Aspects of Charmonium Production and a New Look at J/$\psi$ Suppression
• The p_T Spectrum in Heavy-Flavour Photoproduction
• Spectroscopy and Regge trajectories of heavy baryons in the relativistic quark-diquark picture
• String Formation Beyond Leading Colour
• Medium Modifications and Production of Charmonia at LHC
• Heavy Quark Production in p+p and Energy Loss and Flow of Heavy Quarks in Au+Au Collisions at sqrt(s_NN)=200 GeV
• J/psi Transverse Momentum Distribution in High Energy Nuclear Collisions
• Measurement of b hadron production fractions in 7 TeV pp collisions
• Measurement of Prompt Charm Meson Production Cross Sections in p anti-p Collisions at s**(1/2) = 1.96 TeV
• Measurement of the differential cross-sections of inclusive, prompt and non-prompt J/psi production in proton-proton collisions at sqrt(s) = 7 TeV
• Nuclear modification factor of D${}^0$ mesons in PbPb collisions at $\sqrt{s_{\mathrm{NN}}}=$ 5.02 TeV
• Inclusive Charmed-Meson Production at the CERN LHC
• Measurement of charm production at central rapidity in proton-proton collisions at $\sqrt{s}=2.76$ TeV
• Prompt charm production in pp collisions at sqrt(s)=7 TeV
• Measurements of prompt charm production cross-sections in $pp$ collisions at $\sqrt{s}=13\mathrm{TeV}$
• Perturbative QCD Fragmentation Functions as a Model for Heavy-Quark Fragmentation
• J/$\psi$ suppression at forward rapidity in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• Inclusive D^{*+-} Production in p p-bar Collisions with Massive Charm Quarks
• Measurements of $D^0$ and $D^{\ast }$ Production in $p$ + $p$ Collisions at $\sqrt{s}$ = 200 GeV
• Charm-Baryon Production in Proton-Proton Collisions
• J/psi and psi(2S) production in pp collisions at sqrt(s) = 7 TeV
• Combined analysis of charm-quark fragmentation-fraction measurements
• Measurement of b-hadron fractions in 13 TeV pp collisions
• Measurement of D-meson production at mid-rapidity in pp collisions at $\sqrt{\mathbf{s}}=7$ TeV
• Charm Hadrons in pp collisions at LHC energy within a Coalescence plus Fragmentation approach
• Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at sqrt(s) = 7 TeV
• Revisiting the D-meson hadroproduction in general-mass variable flavour number scheme
• ${\Lambda }_{\mathrm{c}}^{+}$ production in pp collisions at $\sqrt{s}=7$ TeV and in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• Fragmentation fractions of c and b quarks into charmed hadrons at LEP
• D${}_s^{+}$ meson production at central rapidity in proton-proton collisions at $\sqrt{s}$ = 7 TeV
• Measurement of ${\mathrm{D}}^0$, ${\mathrm{D}}^{+}$, ${\mathrm{D}}^{\ast +}$ and ${{\mathrm{D}}^{+}}_s$ production in pp collisions at $\sqrt{\text{s}}=5.02\mathbf{TeV}$ with ALICE
• ${\mathrm{\Lambda }}_{\mathrm{c}}^{+}$ production and baryon-to-meson ratios in pp and p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV at the LHC
• Measurement of $D^{\ast \pm }$, $D^{\pm }$ and $D_s^{\pm }$ meson production cross sections in $pp$ collisions at $\sqrt{s}=7$ TeV with the ATLAS detector
• New feature of low $p_T$ charm quark hadronization in $pp$ collisions at $\sqrt{s}=7$ TeV
• Production of ${\Lambda }_{\mathrm{c}}^{+}$ baryons in proton-proton and lead-lead collisions at $\sqrt{s_{\mathrm{NN}}}=$ 5.02 TeV
• Measurement of beauty and charm production in pp collisions at $\sqrt{s}=5.02$ TeV via non-prompt and prompt D mesons
• Prompt neutrinos from atmospheric charm in the general-mass variable-flavor-number scheme
• Triple parton scatterings in high-energy proton-proton collisions
• Statistical hadronization of heavy flavor quarks in elementary collisions: successes and failures
• ${\Lambda }_c^{\pm }$ production in pp collisions with a new fragmentation function
• ${\mathrm{\Lambda }}_{\mathrm{c}}^{+}$ production in pp and in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• Multiplicity dependence of (multi-)strange baryons in the canonical ensemble with phase shift corrections
• Measurement of prompt D${}^0$, ${\Lambda }_c^{+}$, and ${\Sigma }_c^{0,++}$(2455) production in pp collisions at $\sqrt{s}=13$ TeV
• Centrality and transverse momentum dependence of inclusive J/$\psi$ production at midrapidity in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• Measurement of Ratios of Fragmentation Fractions for Bottom Hadrons in p-pbar Collisions at sqrt{s}=1.96 TeV
• Measurement of the cross sections of ${\Xi }_{\mathrm{c}}^0$ and ${\Xi }_{\mathrm{c}}^{+}$ baryons and branching-fraction ratio BR(${\Xi }_{\mathrm{c}}^0\to {\Xi }^{-}{\mathrm{e}}^{+}{\nu }_{\mathrm{e}}$)/BR(${\Xi }_{\mathrm{c}}^0\to {\Xi }^{-}{\pi }^{+}$) in pp collisions at 13 TeV
• Measurement of the production cross section of prompt ${\Xi }_{\mathrm{c}}^0$ baryons at midrapidity in pp collisions at $\sqrt{s}$ = 5.02 TeV
• First measurement of ${\Xi }_{\mathrm{c}}^0$ production in pp collisions at $\sqrt{\mathbf{s}}$ = 7 TeV
• Inclusive J/$\psi$ production at mid-rapidity in pp collisions at $\sqrt{s}$ = 5.02 TeV
• Production of ${\Lambda }_c$ baryons at the LHC within the $k_T$-factorization approach and independent parton fragmentation picture
• Prompt ${\Lambda }_c^{+}$ production in $p\mathrm{Pb}$ collisions at $\sqrt{s_{NN}}=5.02$ TeV

Cited by in corpus (7)

• X(3872) Production in Relativistic Heavy-Ion Collisions
• Charmonium Transport in Ultra-Relativistic Heavy-Ion Collisions at the LHC
• Recent ALICE results on charm production and hadronisation
• Measurement of prompt ${\mathrm{D}}_{\mathrm{s}}^{+}$-meson production and azimuthal anisotropy in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• Heavy flavour production and spectroscopy
• Measurements of charm production in pp collisions with ALICE
• First measurement of ${\mathrm{\Omega }}_{\mathrm{c}}^0$ production in pp collisions at $\sqrt{s}=13$ TeV with ALICE