Analysis of the apparent nuclear modification in peripheral Pb–Pb collisions at 5.02 TeV
ALICE Collaboration. (2019). Analysis of the apparent nuclear modification in peripheral Pb–Pb collisions at 5.02 TeV. Physics Letters B, 793, 420-432. https://doi.org/10.1016/j.physletb.2019.04.047
Published inPhysics Letters B
© 2019 Conseil Européen pour la Recherche Nucléaire.
Charged-particle spectra at midrapidity are measured in Pb–Pb collisions at the centre-of-mass energy per nucleon–nucleon pair TeV and presented in centrality classes ranging from most central (0–5%) to most peripheral (95–100%) collisions. Possible medium effects are quantified using the nuclear modification factor () by comparing the measured spectra with those from proton–proton collisions, scaled by the number of independent nucleon–nucleon collisions obtained from a Glauber model. At large transverse momenta (), the average is found to increase from about 0.15 in 0–5% central to a maximum value of about 0.8 in 75–85% peripheral collisions, beyond which it falls off strongly to below 0.2 for the most peripheral collisions. Furthermore, initially exhibits a positive slope as a function of in the 8–20 interval, while for collisions beyond the 80% class the slope is negative. To reduce uncertainties related to event selection and normalization, we also provide the ratio of in adjacent centrality intervals. Our results in peripheral collisions are consistent with a PYTHIA-based model without nuclear modification, demonstrating that biases caused by the event selection and collision geometry can lead to the apparent suppression in peripheral collisions. This explains the unintuitive observation that is below unity in peripheral Pb–Pb, but equal to unity in minimum-bias p–Pb collisions despite similar charged-particle multiplicities. ...
Publication in research information system
MetadataShow full item record
Showing items with similar title or keywords.
Coherent J/ψ and ψ′ photoproduction at midrapidity in ultra-peripheral Pb–Pb collisions at √sNN = 5.02 TeV ALICE Collaboration (Springer, 2021)The coherent photoproduction of J/ψ and ψ′ mesons was measured in ultra-peripheral Pb–Pb collisions at a center-of-mass energy √sNN = 5.02 TeV with the ALICE detector. Charmonia are detected in the central rapidity region ...
Helenius, I. (Sissa Medialab srl, 2019)In this talk we apply the photoproduction framework recently implemented into the PYTHIA 8 Monte Carlo event generator to study the potential of photo-nuclear dijets in ultra-peripheral Pb+Pb collisions at the LHC to further ...
First measurement of coherent ρ0 photoproduction in ultra-peripheral Xe–Xe collisions at √sNN = 5.44 TeV ALICE Collaboration (Elsevier BV, 2021)The first measurement of the coherent photoproduction of ρ0 vector mesons in ultra-peripheral Xe–Xe collisions at sNN=5.44 TeV is presented. This result, together with previous HERA γp data and γ–Pb measurements from ALICE, ...
Probing chemical freeze-out criteria in relativistic nuclear collisions with coarse grained transport simulations Reichert, Tom; Inghirami, Gabriele; Bleicher, Marcus (Springer, 2020)We introduce a novel approach based on elastic and inelastic scattering rates to extract the hyper-surface of the chemical freeze-out from a hadronic transport model in the energy range from Elab = 1.23 AGeV to √sNN = 62.4 ...
Nucleon dissociation and incoherent J/ψ photoproduction on nuclei in ion ultraperipheral collisions at the CERN Large Hadron Collider Guzey, Vadim; Strikman, M.; Zhalov, M. (American Physical Society, 2019)Using the general notion of cross section fluctuations in hadron-nucleus scattering at high energies, we derive an expression for the cross section of incoherent J / ψ photoproduction on heavy nuclei d σ γ A ...