https://scholars.lib.ntu.edu.tw/handle/123456789/510812
Title: | The production of isolated photons in PbPb and pp collisions at $\sqrt{s_\mathrm{NN}} =$ 5.02 TeV | Authors: | KAI-FENG CHEN PAO-TI CHANG RONG-SHYANG LU WEI-SHU HOU |
Keywords: | Hadron-Hadron scattering (experiments) | Heavy-ion collision | Photon production; High Energy Physics - Experiment; High Energy Physics - Experiment; Nuclear Experiment | Issue Date: | 28-Mar-2020 | Journal Volume: | 2020 | Journal Issue: | 7 | Source: | JHEP 07 (2020) 116 | Abstract: | The transverse energy ($E_\mathrm{T}^{\gamma}$) spectra of photons isolated from other particles are measured using proton-proton (pp) and lead-lead (PbPb) collisions at the LHC at $\sqrt{s_\mathrm{NN}} =$ 5.02 TeV with integrated luminosities of 27.4 pb$^{-1}$and 404 $\mu$b$^{-1}$ for pp and PbPb data, respectively. The results are presented for photons with 25 $<$ $E_\mathrm{T}^{\gamma}$ $<$ 200 GeV in the pseudorapidity range $|\eta|$ $<$ 1.44, and for different centrality intervals for PbPb collisions. Photon production in PbPb collisions is consistent with that in pp collisions scaled by the number of binary nucleon-nucleon collisions, demonstrating that photons do not interact with the quark-gluon plasma. Therefore, isolated photons can provide information about the initial energy of the associated parton in photon+jet measurements. The results are compared with predictions from the next-to-leading-order JETPHOX generator for different parton distribution functions (PDFs) and nuclear PDFs (nPDFs). The comparisons can help to constrain the nPDFs global fits. |
Description: | Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/HIN-18-016 (CMS Public Pages) |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/510812 | ISSN: | 1029-8479 | DOI: | 10.1007/JHEP07(2020)116 |
Appears in Collections: | 物理學系 |
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