论文标题
在$ \ sqrt {s_ \ mathrm {nn}} = $ 5.02 TEV中的PBPB和PP碰撞中隔离光子的生产
The production of isolated photons in PbPb and pp collisions at $\sqrt{s_\mathrm{NN}} =$ 5.02 TeV
论文作者
论文摘要
从其他颗粒中隔离的光子的横向能（$ e_ \ mathrm {t}^γ$）是使用质子 - 蛋白质（PP）和LHC上的铅铅（PP）（PBPB）碰撞测量的。 Pb $^{ - 1} $和404 $μ$ b $^{ - 1} $分别用于PP和PBPB数据。为25 $ <$ $ e_ \ mathrm {t}^γ$ $ <$ <$ <$ <$ 200 GEV的光子提供了结果。 PBPB碰撞中的光子产生与PP碰撞中的二进制核子核子碰撞数量缩放的光子碰撞相一致，这表明光子与夸克 - 胶状等离子体不相互作用。因此，孤立的光子可以提供有关光子+喷射测量中相关部分的初始能量的信息。将结果与来自近级喷气量发电机的预测进行了比较。比较可以帮助限制NPDFS全局拟合。
The transverse energy ($E_\mathrm{T}^γ$) spectra of photons isolated from other particles are measured using proton-proton (pp) and lead-lead (PbPb) collisions at the LHC at $\sqrt{s_\mathrm{NN}} =$ 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 $<$ $E_\mathrm{T}^γ$ $<$ 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.
