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Item type:Publication, Measurement of beauty production via non-prompt D0 mesons in Pb-Pb collisions at √sNN = 5.02 TeV(Springer Science and Business Media Deutschland GmbH, 2022-12-01)A bstract The production of non-prompt D 0 mesons from beauty-hadron decays was measured at midrapidity (| y | < 0 . 5) in Pb-Pb collisions at a nucleon-nucleon center-of-mass energy of $$ \sqrt{{\textrm{s}}_{\textrm{NN}}} $$ s NN = 5 . 02 TeV with the ALICE experiment at the LHC. Their nuclear modification factor ( R AA ), measured for the first time down to p T = 1 GeV /c in the 0–10% and 30–50% centrality classes, indicates a significant suppression, up to a factor of about three, for p T > 5 GeV /c in the 0–10% central Pb-Pb collisions. The data are described by models that include both collisional and radiative processes in the calculation of beauty-quark energy loss in the quark-gluon plasma, and quark recombination in addition to fragmentation as a hadronisation mechanism. The ratio of the non-prompt to prompt D 0 -meson R AA is larger than unity for p T > 4 GeV /c in the 0–10% central Pb-Pb collisions, as predicted by models in which beauty quarks lose less energy than charm quarks in the quark-gluon plasma because of their larger mass. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Measurement of beauty-quark production in pp collisions at √s = 13 TeV via non-prompt D mesons(Springer Science and Business Media Deutschland GmbH, 2024-10-01)The pT-differential production cross sections of non-prompt D0, D+, and Ds+ mesons originating from beauty-hadron decays are measured in proton–proton collisions at a centre-of-mass energy s = 13 TeV. The measurements are performed at midrapidity, |y| < 0.5, with the data sample collected by ALICE from 2016 to 2018. The results are in agreement with predictions from several perturbative QCD calculations. The fragmentation fraction of beauty quarks to strange mesons divided by the one to non-strange mesons, fs/(fu + fd), is found to be 0.114 ± 0.016 (stat.) ± 0.006 (syst.) ± 0.003 (BR) ± 0.003 (extrap.). This value is compatible with previous measurements at lower centre-of-mass energies and in different collision systems in agreement with the assumption of universality of fragmentation functions. In addition, the dependence of the non-prompt D meson production on the centre-of-mass energy is investigated by comparing the results obtained at s = 5.02 and 13 TeV, showing a hardening of the non-prompt D-meson pT-differential production cross section at higher s. Finally, the bb¯ production cross section per unit of rapidity at midrapidity is calculated from the non-prompt D0, D+, Ds+, and Λc+ hadron measurements, obtaining dσ/dy=75.2±3.2stat.±5.2syst.−3.2+12.3extrap. μb. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Measurement of beauty production via non-prompt charm hadrons in p–Pb collisions at √sNN = 5.02 TeV(Springer Science and Business Media Deutschland GmbH, 2024-11-01)The production cross sections of D0, D+, and Λc+ hadrons originating from beauty-hadron decays (i.e. non-prompt) were measured for the first time at midrapidity in proton–lead (p–Pb) collisions at the center-of-mass energy per nucleon pair of sNN = 5.02 TeV. Nuclear modification factors (RpPb) of non-prompt D0, D+, and Λc+ are calculated as a function of the transverse momentum (pT) to investigate the modification of the momentum spectra measured in p–Pb collisions with respect to those measured in proton–proton (pp) collisions at the same energy. The RpPb measurements are compatible with unity and with the measurements in the prompt charm sector, and do not show a significant pT dependence. The pT-integrated cross sections and pT-integrated RpPb of non-prompt D0 and D+ mesons are also computed by extrapolating the visible cross sections down to pT = 0. The non-prompt D-meson RpPb integrated over pT is compatible with unity and with model calculations implementing modification of the parton distribution functions of nucleons bound in nuclei with respect to free nucleons. The non-prompt Λc+/D0 and D+/D0 production ratios are computed to investigate hadronisation mechanisms of beauty quarks into mesons and baryons. The measured ratios as a function of pT display a similar trend to that measured for charm hadrons in the same collision system. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Prompt and non-prompt J/ψ production at midrapidity in Pb–Pb collisions at √sNN = 5.02 TeV(Springer Science and Business Media Deutschland GmbH, 2024-02-01)The transverse momentum (pT) and centrality dependence of the nuclear modification factor RAA of prompt and non-prompt J/ψ, the latter originating from the weak decays of beauty hadrons, have been measured by the ALICE collaboration in Pb–Pb collisions at sNN = 5.02 TeV. The measurements are carried out through the e+e− decay channel at midrapidity (|y| < 0.9) in the transverse momentum region 1.5 < pT < 10 GeV/c. Both prompt and non-prompt J/ψ measurements indicate a significant suppression for pT > 5 GeV/c, which becomes stronger with increasing collision centrality. The results are consistent with similar LHC measurements in the overlapping pT intervals, and cover the kinematic region down to pT = 1.5 GeV/c at midrapidity, not accessible by other LHC experiments. The suppression of prompt J/ψ in central and semicentral collisions exhibits a decreasing trend towards lower transverse momentum, described within uncertainties by models implementing J/ψ production from recombination of c and c¯ quarks produced independently in different partonic scatterings. At high transverse momentum, transport models including quarkonium dissociation are able to describe the suppression for prompt J/ψ. For non-prompt J/ψ, the suppression predicted by models including both collisional and radiative processes for the computation of the beauty-quark energy loss inside the quark-gluon plasma is consistent with measurements within uncertainties. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Measurement of the Production of Charm Jets Tagged with D0 Mesons in pp Collisions at √s = 5.02 and 13 TeV(Springer Science and Business Media Deutschland GmbH, 2023-06-01)The measurement of the production of charm jets, identified by the presence of a D0 meson in the jet constituents, is presented in proton–proton collisions at centre-of-mass energies of s = 5.02 and 13 TeV with the ALICE detector at the CERN LHC. The D0 mesons were reconstructed from their hadronic decay D0 → K − π + and the respective charge conjugate. Jets were reconstructed from D0-meson candidates and charged particles using the anti-k T algorithm, in the jet transverse momentum range 5 < p T,chjet < 50 GeV/c, pseudorapidity |η jet| < 0.9 − R, and with the jet resolution parameters R = 0.2, 0.4, 0.6. The distribution of the jet momentum fraction carried by a D0 meson along the jet axis (z‖ch) was measured in the range 0.4 < z‖ch < 1.0 in four ranges of the jet transverse momentum. Comparisons of results for different collision energies and jet resolution parameters are also presented. The measurements are compared to predictions from Monte Carlo event generators based on leading-order and next-to-leading-order perturbative quantum chromodynamics calculations. A generally good description of the main features of the data is obtained in spite of a few discrepancies at low p T,chjet. Measurements were also done for R = 0.3 at s = 5.02 and are shown along with their comparisons to theoretical predictions in an appendix to this paper. [Figure not available: see fulltext.]. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Measurement of the Non-Prompt D-Meson Fraction as a Function of Multiplicity in Proton-Proton Collisions at √s = 13 TeV(Springer Science and Business Media Deutschland GmbH, 2023-10-01)The fractions of non-prompt (i.e. originating from beauty-hadron decays) D0 and D+ mesons with respect to the inclusive yield are measured as a function of the charged-particle multiplicity in proton-proton collisions at a centre-of-mass energy of s = 13 TeV with the ALICE detector at the LHC. The results are reported in intervals of transverse momentum (p T) and integrated in the range 1 < p T < 24 GeV/c. The fraction of non-prompt D0 and D+ mesons is found to increase slightly as a function of p T in all the measured multiplicity intervals, while no significant dependence on the charged-particle multiplicity is observed. In order to investigate the production and hadronisation mechanisms of charm and beauty quarks, the results are compared to PYTHIA 8 as well as EPOS 3 and EPOS 4 Monte Carlo simulations, and to calculations based on the colour glass condensate including three-pomeron fusion. [Figure not available: see fulltext.]. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Charm Production and Fragmentation Fractions at Midrapidity in pp Collisions at s = 13 TeV(Springer Science and Business Media Deutschland GmbH, 2023-12-01)Measurements of the production cross sections of prompt D0, D+, D*+, Ds+, Λc+, and Ξc+ charm hadrons at midrapidity in proton-proton collisions at s = 13 TeV with the ALICE detector are presented. The D-meson cross sections as a function of transverse momentum (pT) are provided with improved precision and granularity. The ratios of pT-differential meson production cross sections based on this publication and on measurements at different rapidity and collision energy provide a constraint on gluon parton distribution functions at low values of Bjorken-x (10−5–10−4). The measurements of Λc+ (Ξc+) baryon production extend the measured pT intervals down to pT = 0(3) GeV/c. These measurements are used to determine the charm-quark fragmentation fractions and the cc¯ production cross section at midrapidity (|y| < 0.5) based on the sum of the cross sections of the weakly-decaying ground-state charm hadrons D0, D+, Ds+, Λc+, Ξc0 and, for the first time, Ξc+, and of the strongly-decaying J/ψ mesons. The first measurements of Ξc+ and Σc0,++ fragmentation fractions at midrapidity are also reported. A significantly larger fraction of charm quarks hadronising to baryons is found compared to e+e− and ep collisions. The cc¯ production cross section at midrapidity is found to be at the upper bound of state-of-the-art perturbative QCD calculations.2 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, J/ψ-hadron correlations at midrapidity in pp collisions at s = 13 TeV(Springer Nature, 2025-07-01)A bstract We report on the measurement of inclusive, non-prompt, and prompt J/ ψ -hadron correlations by the ALICE Collaboration at the CERN Large Hadron Collider in pp collisions at a center-of-mass energy of 13 TeV. The correlations are studied at midrapidity ( |y| < 0 . 9) in the transverse momentum ranges p T < 40 GeV /c for the J/ ψ and 0 . 15 < p T < 10 GeV /c and | η | < 0 . 9 for the associated hadrons. The measurement is based on minimum bias and high multiplicity data samples corresponding to integrated luminosities of L int = 34 nb − 1 and L int = 6 . 9 pb − 1 , respectively. In addition, two more data samples are employed, requiring, on top of the minimum bias condition, a threshold on the tower energy of E = 4 and 9 GeV in the ALICE electromagnetic calorimeters, which correspond to integrated luminosities of L int = 0 . 9 pb − 1 and L int = 8 . 4 pb − 1 , respectively. The azimuthally integrated near and away side yields of associated charged hadrons per J/ ψ trigger are presented as a function of the J/ ψ and associated hadron transverse momentum. The measurements are discussed in comparison to PYTHIA calculations.2