The transverse momentum distributions of the strange and double-strange hyperon resonances (Σ(1385)±, Ξ(1530)0) produced in p–Pb collisions at sNN=5.02 TeV were measured in the rapidity range ...-0.5<yCMS<0 for event classes corresponding to different charged-particle multiplicity densities, ⟨dNch/dηlab⟩. The mean transverse momentum values are presented as a function of ⟨dNch/dηlab⟩, as well as a function of the particle masses and compared with previous results on hyperon production. The integrated yield ratios of excited to ground-state hyperons are constant as a function of ⟨dNch/dηlab⟩. The equivalent ratios to pions exhibit an increase with ⟨dNch/dηlab⟩, depending on their strangeness content.
The azimuthal correlations of D mesons with charged particles were measured with the ALICE apparatus in pp collisions at s=7TeV and p–Pb collisions at sNN=5.02TeV at the Large Hadron Collider. D0, ...D+, and D∗+ mesons and their charge conjugates with transverse momentum 3<pT<16GeV/c and rapidity in the nucleon-nucleon centre-of-mass system |ycms|<0.5 (pp collisions) and -0.96<ycms<0.04 (p–Pb collisions) were correlated to charged particles with pT>0.3GeV/c. The yield of charged particles in the correlation peak induced by the jet containing the D meson and the peak width are compatible within uncertainties in the two collision systems. The data are described within uncertainties by Monte-Carlo simulations based on PYTHIA, POWHEG, and EPOS 3 event generators.
We present results on transverse momentum (Formula: see text) and rapidity (Formula: see text) differential production cross sections, mean transverse momentum and mean transverse momentum square of ...inclusive Formula: see text and Formula: see text at forward rapidity (Formula: see text) as well as Formula: see text-to-Formula: see text cross section ratios. These quantities are measured in pp collisions at center of mass energies Formula: see text and 13 TeV with the ALICE detector. Both charmonium states are reconstructed in the dimuon decay channel, using the muon spectrometer. A comprehensive comparison to inclusive charmonium cross sections measured at Formula: see text, 7 and 8 TeV is performed. A comparison to non-relativistic quantum chromodynamics and fixed-order next-to-leading logarithm calculations, which describe prompt and non-prompt charmonium production respectively, is also presented. A good description of the data is obtained over the full Formula: see text range, provided that both contributions are summed. In particular, it is found that for Formula: see text GeV/
the non-prompt contribution reaches up to 50% of the total charmonium yield.
The transverse momentum distributions of the strange and double-strange hyperon resonances (
,
) produced in p-Pb collisions at
TeV were measured in the rapidity range
for event classes corresponding ...to different charged-particle multiplicity densities,
d
/d
. The mean transverse momentum values are presented as a function of
d
/d
, as well as a function of the particle masses and compared with previous results on hyperon production. The integrated yield ratios of excited to ground-state hyperons are constant as a function of
d
/d
. The equivalent ratios to pions exhibit an increase with
d
/d
, depending on their strangeness content.
The azimuthal correlations of D mesons with charged particles were measured with the ALICE apparatus in pp collisions at Formula: see text and p-Pb collisions at Formula: see text at the Large Hadron ...Collider. Formula: see text, Formula: see text, and Formula: see text mesons and their charge conjugates with transverse momentum Formula: see text and rapidity in the nucleon-nucleon centre-of-mass system Formula: see text (pp collisions) and Formula: see text (p-Pb collisions) were correlated to charged particles with Formula: see text. The yield of charged particles in the correlation peak induced by the jet containing the D meson and the peak width are compatible within uncertainties in the two collision systems. The data are described within uncertainties by Monte-Carlo simulations based on PYTHIA, POWHEG, and EPOS 3 event generators.
The invariant differential cross sections for inclusive Formula: see text and Formula: see text mesons at midrapidity were measured in pp collisions at Formula: see text TeV for transverse momenta ...Formula: see text GeV/
and Formula: see text GeV/
, respectively, using the ALICE detector. This large range in Formula: see text was achieved by combining various analysis techniques and different triggers involving the electromagnetic calorimeter (EMCal). In particular, a new single-cluster, shower-shape based method was developed for the identification of high-Formula: see text neutral pions, which exploits that the showers originating from their decay photons overlap in the EMCal. Above 4 GeV/Formula: see text, the measured cross sections are found to exhibit a similar power-law behavior with an exponent of about 6.3. Next-to-leading-order perturbative QCD calculations differ from the measured cross sections by about 30% for the Formula: see text, and between 30-50% for the Formula: see text meson, while generator-level simulations with PYTHIA 8.2 describe the data to better than 10-30%, except at Formula: see text GeV/Formula: see text. The new data can therefore be used to further improve the theoretical description of Formula: see text and Formula: see text meson production.
The polarization of the Λ and Λover ¯ hyperons along the beam (z) direction, P_{z}, has been measured in Pb-Pb collisions at sqrts_{NN}=5.02 TeV recorded with ALICE at the Large Hadron Collider ...(LHC). The main contribution to P_{z} comes from elliptic flow-induced vorticity and can be characterized by the second Fourier sine coefficient P_{z,s2}=⟨P_{z}sin(2φ-2Ψ_{2})⟩, where φ is the hyperon azimuthal emission angle and Ψ_{2} is the elliptic flow plane angle. We report the measurement of P_{z,s2} for different collision centralities and in the 30%-50% centrality interval as a function of the hyperon transverse momentum and rapidity. The P_{z,s2} is positive similarly as measured by the STAR Collaboration in Au-Au collisions at sqrts_{NN}=200 GeV, with somewhat smaller amplitude in the semicentral collisions. This is the first experimental evidence of a nonzero hyperon P_{z} in Pb-Pb collisions at the LHC. The comparison of the measured P_{z,s2} with the hydrodynamic model calculations shows sensitivity to the competing contributions from thermal and the recently found shear-induced vorticity, as well as to whether the polarization is acquired at the quark-gluon plasma or the hadronic phase.
The p_{T}-differential production cross sections of prompt D^{0}, Λ_{c}^{+}, and Σ_{c}^{0,++}(2455) charmed hadrons are measured at midrapidity (|y|<0.5) in pp collisions at sqrts=13 TeV. This is ...the first measurement of Σ_{c}^{0,++} production in hadronic collisions. Assuming the same production yield for the three Σ_{c}^{0,+,++} isospin states, the baryon-to-meson cross section ratios Σ_{c}^{0,+,++}/D^{0} and Λ_{c}^{+}/D^{0} are calculated in the transverse momentum (p_{T}) intervals 2<p_{T}<12 and 1<p_{T}<24 GeV/c. Values significantly larger than in e^{+}e^{-} collisions are observed, indicating for the first time that baryon enhancement in hadronic collisions also extends to the Σ_{c}. The feed-down contribution to Λ_{c}^{+} production from Σ_{c}^{0,+,++} is also reported and is found to be larger than in e^{+}e^{-} collisions. The data are compared with predictions from event generators and other phenomenological models, providing a sensitive test of the different charm-hadronization mechanisms implemented in the models.
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