| Talk | ||||||
| Title | Nuclear suppression in inelastic nucleon-nucleon cross section | |||||
| Video |
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| Author(s) | Helenius, Ilkka (speaker) (University of Jyväskylä) | |||||
| Corporate author(s) | CERN. Geneva | |||||
| Imprint | 2021-01-11. - 1267. | |||||
| Series | (Conferences) (Initial Stages 2021) | |||||
| Lecture note | on 2021-01-11T17:45:00 | |||||
| Subject category | Conferences | |||||
| Abstract | In high-energy heavy-ion collisions the standard procedure to turn the measured hard-process yields into centrality dependent cross sections is to use normalization factors calculated with the Monte-Carlo Glauber model. Canonically it is assumed that a necessary input, the inelastic nucleon-nucleon cross section, is unmodified wrt. the measured cross section in proton-proton collisions. At the LHC energies particle production is, however, dominated by the small-x region where nuclear suppression due to shadowing or saturation phenomena is expected. In this talk we elaborate this idea by using the recent Run 2 ATLAS data for electro-weak boson production in lead-lead collisions. Using the state-of-the art NNLO calculations we turn the canonical approach around and use the minimum-bias Z and W boson production measurements to obtain the normalization factors preferred by the data. Through Monte-Carlo Glauber simulations we find that the data prefer a significantly suppressed value for the inelastic nucleon-nucleon cross section, $41.5^{+16.2}_{-12.0}$ mb instead of the nominal $70 \pm 5$ mb. Furthermore, using the obtained value, the unexpected rise of Z and W boson nuclear modification ratios towards more peripheral collisions is tamed and the data become compatible with a flat behaviour or even hint of a mild decrease. Also, we demonstrate that the obtained suppression is in line with an eikonal minijet model including nuclear shadowing. | |||||
| Copyright/License | © 2021-2024 CERN | |||||
| Submitted by | [email protected] | |||||
Record created 2021-01-12, last modified 2024-06-26
Talk details