Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe

3-year results of the German nationwide survey on eye injuries caused by fireworks

Background On festive days worldwide eyes are severely injured by fireworks. The data on the number and severity are to date not registered in Germany. Objective How frequent are firework-induced injuries in Germany, who are the affected, how serious are the injuries, which forms of treatment are necessary and how frequent are accompanying injuries? Method A German nationwide online-based survey was carried out in all inpatient eye departments and data over the last 3 consecutive years were descriptively analyzed. Results From New Years Eve 2016/2017, when 41 eye departments sent in data, the participation could be increased to 51 eye departments in 2018/2019. More than one third (33-39%) of all 1356 patients over 3 years were minors, 60% were younger than 25 years old and roughly 60% of patients were injured as bystanders or in an unclear situation. In total 25% of all eye injuries were considered severe and required inpatient treatment. Accompanying injuries of the other eye, the face and hands were more frequent in minors than in adults. Eyeball ruptures were reported in 10 minors and 38 adults over the 3 years. Conclusion Particularly minors and bystanders need better protection

ϒ production in p–Pb collisions at √s=8.16 TeV

ϒ production in p–Pb interactions is studied at the centre-of-mass energy per nucleon–nucleon collision √sNN = 8.16 TeV with the ALICE detector at the CERN LHC. The measurement is performed reconstructing bottomonium resonances via their dimuon decay channel, in the centre-of-mass rapidity intervals 2.03 < ycms < 3.53 and −4.46 < ycms < −2.96, down to zero transverse momentum. In this work, results on the ϒ(1S) production cross section as a function of rapidity and transverse momentum are presented. The corresponding nuclear modification factor shows a suppression of the ϒ(1S) yields with respect to pp collisions, both at forward and backward rapidity. This suppression is stronger in the low transverse momentum region and shows no significant dependence on the centrality of the interactions. Furthermore, the ϒ(2S) nuclear modification factor is evaluated, suggesting a suppression similar to that of the ϒ(1S). A first measurement of the ϒ(3S) has also been performed. Finally, results are compared with previous ALICE measurements in p–Pb collisions at √sNN = 5.02 TeV and with theoretical calculations.publishedVersio

Lambda(+)(C) production in pb-pb collisions at root S-NN=5.02 TeV

A measurement of the production of prompt +cbaryons in Pb–Pb collisions at √sNN=5.02 TeV with the ALICE detector at the LHC is reported. The +cand −cwere reconstructed at midrapidity (|y| <0.5) via the hadronic decay channel +c→pK0S(and charge conjugate) in the transverse momentum and centrality intervals 6 <pT<12 GeV/cand 0–80%. The +c/D0ratio, which is sensitive to the charm quark hadronisation mechanisms in the medium, is measured and found to be larger than the ratio measured in minimum-bias pp collisions at √s=7TeV and in p–Pb collisions at √sNN=5.02 TeV. In particular, the values in p–Pb and Pb–Pb collisions differ by about two standard deviations of the combined statistical and systematic uncertainties in the common pTinterval covered by the measurements in the two collision systems. The +c/D0ratio is also compared with model calculations including different implementations of charm quark hadronisation. The measured ratio is reproduced by models implementing a pure coalescence scenario, while adding a fragmentation contribution leads to an underestimation. The +cnuclear modification factor, RAA, is also presented. The measured values of the RAAof +c, D+sand non-strange D mesons are compatible within the combined statistical and systematic uncertainties. They show, however, a hint of a hierarchy (RD0AA<RD+sAA<R +cAA), conceivable with a contribution from coalescence mechanisms to charm hadron formation in the medium

Λ c+ production in Pb–Pb collisions at s NN =5.02 TeV

AA measurement of the production of prompt Λ c + baryons in Pb–Pb collisions at s NN =5.02 TeV with the ALICE detector at the LHC is reported. The Λ c + and Λ‾ c − were reconstructed at midrapidity (|y|&lt;0.5) via the hadronic decay channel Λ c + →pK S 0 (and charge conjugate) in the transverse momentum and centrality intervals

Transverse-momentum and event-shape dependence of D-meson flow harmonics in Pb–Pb collisions at √sNN = 5.02 TeV

The elliptic and triangular flow coefficients v2 and v3 of prompt D0, D+, and D∗+ mesons were measured at midrapidity (|y| < 0.8) in Pb–Pb collisions at the centre-of-mass energy per nucleon pair of √sNN = 5.02 TeV with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays in the transverse momentum interval 1 < pT < 36 GeV/c in central (0–10%) and semi-central (30–50%) collisions. Compared to pions, protons, and J/ψ mesons, the average D-meson vn harmonics are compatible within uncertainties with a mass hierarchy for pT 3 GeV/c, and are similar to those of charged pions for higher pT. The coupling of the charm quark to the light quarks in the underlying medium is further investigated with the application of the event-shape engineering (ESE) technique to the D-meson v2 and pT-differential yields. The D-meson v2 is correlated with average bulk elliptic flow in both central and semi-central collisions. Within the current precision, the ratios of per-event Dmeson yields in the ESE-selected and unbiased samples are found to be compatible with unity. All the measurements are found to be reasonably well described by theoretical calculations including the effects of charm-quark transport and the recombination of charm quarks with light quarks in a hydrodynamically expanding medium