J/psi production as a function of charged-particle pseudorapidity density in p-Pb collisions at root s(NN)=5.02 TeV

We report measurements of the inclusive J/ψ yield and average transverse momentum as a function of charged-particle pseudorapidity density dNch/dη in p–Pb collisions at sNN=5.02TeV with ALICE at the LHC. The observables are normalised to their corresponding averages in non-single diffractive events. An increase of the normalised J/ψ yield with normalised dNch/dη, measured at mid-rapidity, is observed at mid-rapidity and backward rapidity. At forward rapidity, a saturation of the relative yield is observed for high charged-particle multiplicities. The normalised average transverse momentum at forward and backward rapidities increases with multiplicity at low multiplicities and saturates beyond moderate multiplicities. In addition, the forward-to-backward nuclear modification factor ratio is also reported, showing an increasing suppression of J/ψ production at forward rapidity with respect to backward rapidity for increasing charged-particle multiplicity

Erratum to: Insight into particle production mechanisms via angular correlations of identified particles in pp collisions at s = 7 TeV (The European Physical Journal C, (2017), 77, 8, (569), 10.1140/epjc/s10052-017-5129-6)

We have identified a mistake in how Fig. 1 is referenced in the text of the article Eur. Phys. J. C 77 (2017) no. 8, 569 which affected three paragraphs of the results section. The corrected three paragraphs as well as the unmodified accompanying figure are reproduced in this document with the correct labeling. In addition, an editing issue led to a missing acknowledgements section. The missing section is reproduced at the end of this document in the manner in which it should have appeared in the published article. © 2019, CERN for the benefit of the ALICE collaboration

First measurement of jet mass in PbâPb and pâPb collisions at the LHC

This letter presents the first measurement of jet mass in Pb–Pb and p–Pb collisions at sNN=2.76 TeV and sNN=5.02 TeV, respectively. Both the jet energy and the jet mass are expected to be sensitive to jet quenching in the hot Quantum Chromodynamics (QCD) matter created in nuclear collisions at collider energies. Jets are reconstructed from charged particles using the anti-kT jet algorithm and resolution parameter R=0.4. The jets are measured in the pseudorapidity range |ηjet|<0.5 and in three intervals of transverse momentum between 60 GeV/c and 120 GeV/c. The measurement of the jet mass in central Pb–Pb collisions is compared to the jet mass as measured in p–Pb reference collisions, to vacuum event generators, and to models including jet quenching. It is observed that the jet mass in central Pb–Pb collisions is consistent within uncertainties with p–Pb reference measurements. Furthermore, the measured jet mass in Pb–Pb collisions is not reproduced by the quenching models considered in this letter and is found to be consistent with PYTHIA expectations within systematic uncertainties

Production of Σ (1385) ± and Ξ (1530) 0 in p–Pb collisions at √sNN=5.02 TeV

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 &amp;lt; yCMS&amp;lt; 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. © 2017, CERN for the benefit of the ALICE collaboration