In:
Journal of High Energy Physics, Springer Science and Business Media LLC, Vol. 2020, No. 7 ( 2020-07)
Abstract:
The transverse energy ( $$ {E}_{\mathrm{T}}^{\upgamma} $$ E T γ ) spectra of photons isolated from other particles are measured using proton-proton (pp) and lead-lead (PbPb) collisions at the LHC at $$ \sqrt{s_{\mathrm{NN}}} $$ s NN = 5 . 02 TeV with integrated luminosities of 27.4 pb − 1 and 404 μ b − 1 for pp and PbPb data, respectively. The results are presented for photons with 25 〈 $$ {E}_{\mathrm{T}}^{\upgamma} $$ E T γ 〈 200 GeV in the pseudorapidity range |η| 〈 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.
Type of Medium:
Online Resource
ISSN:
1029-8479
DOI:
10.1007/JHEP07(2020)116
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2020
detail.hit.zdb_id:
2027350-2