| ATLAS Note | |
| Report number | ATLAS-CONF-2023-059 |
| Title | Charged-hadron yield measurements in photo-nuclear collisions using 5.02 TeV Pb+Pb data with ATLAS |
| The ATLAS collaboration | |
| ATLAS Collaboration | |
| 2023 | |
| 19 Sep 2023 | |
| mult. | |
| All figures including auxiliary figures are available athttps://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/CONFNOTES/ATLAS-CONF-2023-059 | |
| Particle Physics - Experiment | |
| CERN LHC ;ATLAS | |
| HEAVYIONS ;Charged-hadron ;yield ;photo-nuclear ;UPC | |
| This note presents the analysis of charged-hadron measurements in photo-nuclear collisions using 1.73 $\mathrm{nb^{-1}}$ of 5.02 TeV Pb+Pb data collected in 2018 by ATLAS. Candidate photo-nuclear events are selected and background events rejected using a combination of zero degree calorimeter, pseudorapidity gap, and tracking information. The yield of charged hadrons as a function of transverse momentum ($p_{\mathrm{T}}$) and pseudorapidity ($\eta$) is measured in these photo-nuclear collisions as a function of charged-particle multiplicity. The results are compared with 0.10 $\mathrm{nb^{-1}}$ of 5.02 TeV p+Pb data collected in 2016 by ATLAS using similar charged-particle multiplicity selections. These photo-nuclear measurements are important for constraining the photon energy distribution and particle production in Monte Carlo models such as DPMJET-III. Additionally, the results are important to test whether such photo-nuclear collisions may produce small droplets of quark-gluon plasma that flow hydrodynamically. | |
| superseded by:CERN-EP-2025-040 | |
Record created 2023-09-19, last modified 2025-03-12
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