• Browse all
Constraining gluon distributions in nuclei using dijets in proton-proton and proton-lead collisions at $\sqrt{s_{_\mathrm{NN}}} =$ 5.02 TeV

The CMS collaboration
No Journal Information, 2018

Abstract
The pseudorapidity distributions of dijets as a function of their average transverse momentum ($p_\mathrm{T}^\text{ave}$) are measured in proton-lead (pPb) and proton-proton (pp) collisions. The data samples were collected by the CMS experiment at the CERN LHC, at a nucleon-nucleon center-of-mass energy of 5.02 TeV. A significant modification of the pPb spectra with respect to the pp spectra is observed in all $p_\mathrm{T}^\text{ave}$ intervals investigated. The ratios of the pPb and pp distributions are compared to next-to-leading order perturbative quantum chromodynamics calculations with unbound nucleon and nuclear parton distribution functions (PDFs). These results give the first evidence that the gluon PDF at large Bjorken $x$ in lead ions is strongly suppressed with respect to the PDF in unbound nucleons.

  • Table 1a

    Data from Figure 2 (top-left panel)

    10.17182/hepdata.83198.v2/t1

    The ratio of pPb to pp $\eta_{\mathrm{dijet}}$ spectra for dijets in the range $55 < p_{\mathrm{T}}^{\mathrm{ave}} < 75$ GeV.

  • Table 1b

    Data from Figure 2 (top-centre panel)

    10.17182/hepdata.83198.v2/t2

    The ratio of pPb to pp $\eta_{\mathrm{dijet}}$ spectra for dijets in the range $75 < p_{\mathrm{T}}^{\mathrm{ave}} < 95$ GeV.

  • Table 1c

    Data from Figure 2 (bottom-left panel)

    10.17182/hepdata.83198.v2/t3

    The ratio of pPb to pp $\eta_{\mathrm{dijet}}$ spectra for dijets in the range $95 < p_{\mathrm{T}}^{\mathrm{ave}} < 115$ GeV.

  • Table 1d

    Data from Figure 2 (bottom-centre panel)

    10.17182/hepdata.83198.v2/t4

    The ratio of pPb to pp $\eta_{\mathrm{dijet}}$ spectra for dijets in the range $115 < p_{\mathrm{T}}^{\mathrm{ave}} < 150$ GeV.

  • Table 1e

    Data from Figure 2 (bottom-right panel)

    10.17182/hepdata.83198.v2/t5

    The ratio of pPb to pp $\eta_{\mathrm{dijet}}$ spectra for dijets in the range $p_{\mathrm{T}}^{\mathrm{ave}} > 150$ GeV.

  • Table 2

    Data from Figure 3

    10.17182/hepdata.83198.v2/t6

    The ratio of theory to data, for the ratio of the pPb to pp $\eta_{\mathrm{dijet}}$ spectra for $115 < p_{\mathrm{T}}^{\mathrm{ave}}...

  • Table 3a

    Data from Supplementary Figure 1 (top-left panel)

    10.17182/hepdata.83198.v2/t7

    The measured pp dijet pseudorapidity spectra, shifted to match the $\eta_{\mathrm{dijet}}$ range of the pPb collisions, for $55 < p_{\mathrm{T}}^{\mathrm{ave}}...

  • Table 3b

    Data from Supplementary Figure 1 (top-centre panel)

    10.17182/hepdata.83198.v2/t8

    The measured pp dijet pseudorapidity spectra, shifted to match the $\eta_{\mathrm{dijet}}$ range of the pPb collisions, for $75 < p_{\mathrm{T}}^{\mathrm{ave}}...

  • Table 3c

    Data from Supplementary Figure 1 (bottom-left panel)

    10.17182/hepdata.83198.v2/t9

    The measured pp dijet pseudorapidity spectra, shifted to match the $\eta_{\mathrm{dijet}}$ range of the pPb collisions, for $95 < p_{\mathrm{T}}^{\mathrm{ave}}...

  • Table 3d

    Data from Supplementary Figure 1 (bottom-centre panel)

    10.17182/hepdata.83198.v2/t10

    The measured pp dijet pseudorapidity spectra, shifted to match the $\eta_{\mathrm{dijet}}$ range of the pPb collisions, for $115 < p_{\mathrm{T}}^{\mathrm{ave}}...

  • Table 3e

    Data from Supplementary Figure 1 (bottom-right panel)

    10.17182/hepdata.83198.v2/t11

    The measured pp dijet pseudorapidity spectra, shifted to match the $\eta_{\mathrm{dijet}}$ range of the pPb collisions, for $55 < p_{\mathrm{T}}^{\mathrm{ave}}...

  • Table 4a

    Data from Supplementary Figure 2 (top-left panel)

    10.17182/hepdata.83198.v2/t12

    The measured pPb dijet pseudorapidity spectra for $55 < p_{\mathrm{T}}^{\mathrm{ave}} < 75$ GeV using the CT14 as the baseline PDF.

  • Table 4b

    Data from Supplementary Figure 2 (top-centre panel)

    10.17182/hepdata.83198.v2/t13

    The measured pPb dijet pseudorapidity spectra for $75 < p_{\mathrm{T}}^{\mathrm{ave}} < 95$ GeV using the CT14 as the baseline PDF.

  • Table 4c

    Data from Supplementary Figure 2 (bottom-left panel)

    10.17182/hepdata.83198.v2/t14

    The measured pPb dijet pseudorapidity spectra for $95 < p_{\mathrm{T}}^{\mathrm{ave}} < 115$ GeV using the CT14 as the baseline PDF.

  • Table 4d

    Data from Supplementary Figure 2 (bottom-centre panel)

    10.17182/hepdata.83198.v2/t15

    The measured pPb dijet pseudorapidity spectra for $115 < p_{\mathrm{T}}^{\mathrm{ave}} < 150$ GeV using the CT14 as the baseline PDF.

  • Table 4e

    Data from Supplementary Figure 2 (bottom-right panel)

    10.17182/hepdata.83198.v2/t16

    The measured pPb dijet pseudorapidity spectra for $p_{\mathrm{T}}^{\mathrm{ave}} > 150$ GeV using the CT14 as the baseline PDF.

  • Table 5a

    Data from Supplementary Figure 3 (top-left panel)

    10.17182/hepdata.83198.v2/t17

    The measured pPb dijet pseudorapidity spectra for $55 < p_{\mathrm{T}}^{\mathrm{ave}} < 75$ GeV using the MMHT14 as the baseline PDF.

  • Table 5b

    Data from Supplementary Figure 3 (top-centre panel)

    10.17182/hepdata.83198.v2/t18

    The measured pPb dijet pseudorapidity spectra for $75 < p_{\mathrm{T}}^{\mathrm{ave}} < 95$ GeV using the MMHT14 as the baseline PDF.

  • Table 5c

    Data from Supplementary Figure 3 (bottom-left panel)

    10.17182/hepdata.83198.v2/t19

    The measured pPb dijet pseudorapidity spectra for $95 < p_{\mathrm{T}}^{\mathrm{ave}} < 115$ GeV using the MMHT14 as the baseline PDF.

  • Table 5d

    Data from Supplementary Figure 3 (bottom-centre panel)

    10.17182/hepdata.83198.v2/t20

    The measured pPb dijet pseudorapidity spectra for $115 < p_{\mathrm{T}}^{\mathrm{ave}} < 150$ GeV using the MMHT14 as the baseline PDF.

  • Table 5e

    Data from Supplementary Figure 3 (bottom-right panel)

    10.17182/hepdata.83198.v2/t21

    The measured pPb dijet pseudorapidity spectra for $p_{\mathrm{T}}^{\mathrm{ave}} > 150$ GeV using the MMHT14 as the baseline PDF.

Version 2 modifications: Data points themselves didn't change, they were just put in the wrong table: -- the data in table 1b was swapped with the data in 1c, -- and the data in table 3b was swapped with data in table 3c

Loading Data...