CMS-SMP-15-003 ; CERN-EP-2017-085 | ||
Measurements of jet charge with dijet events in pp collisions at $ \sqrt{s} = $ 8 TeV | ||
CMS Collaboration | ||
18 June 2017 | ||
JHEP 10 (2017) 131 | ||
Abstract: Jet charge is an estimator of the electric charge of a quark, antiquark, or gluon initiating a jet. It is based on the momentum-weighted sum of the electric charges of the jet constituents. Measurements of three charge observables of the leading jet in transverse momentum $ p_{\mathrm{T}} $ are performed with dijet events. The analysis is carried out with data collected by the CMS experiment at the CERN LHC in proton-proton collisions at $ \sqrt{s} = $ 8 TeV corresponding to an integrated luminosity of 19.7 fb$^{-1}$. The results are presented as a function of the $ p_{\mathrm{T}}$ of the leading jet and compared to predictions from leading- and next-to-leading-order event generators combined with parton showers. Measured jet charge distributions, unfolded for detector effects, are reported, which expand on previous measurements of the jet charge average and standard deviation in pp collisions. | ||
Links: e-print arXiv:1706.05868 [hep-ex] (PDF) ; CDS record ; inSPIRE record ; HepData record ; CADI line (restricted) ; |
Figures | |
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Figure 1:
Leading-jet $ {p_{\mathrm {T}}} $ distribution in data (points) compared to PYTHIA6 simulation. The PYTHIA6 prediction is normalized to match the total number of events observed in data. Only statistical uncertainties are shown. The filled histograms show the contributions from different types of initiating partons, identified by means of the matching algorithm described in the text. The "others'' category represents those jets that are initiated by parton types, the up antiquark ($\bar{ \mathrm{u} } $), the down antiquark ($\bar{ \mathrm{d} } $), the charm, strange, and bottom quarks and antiquarks ($\mathrm{c} $, $\bar{ \mathrm{c} } $, $\mathrm{s} $, $\bar{ \mathrm{s} } $, $\mathrm{ b } $, $\mathrm{ \bar{b} } $), and any unmatched jets. The data points are shown in the center of each jet $ {p_{\mathrm {T}}} $ bin. |
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Figure 2:
Distributions of jet charge: $Q^\kappa $ (top row), $Q_{L}^\kappa $ (lower left), and $Q_{T}^\kappa $ (lower right), for leading jets and $\kappa =$ 0.6, in data (points) and MC simulations. The top left panel compares the data with the $\mathrm{u} $, $\mathrm{d} $, and $\mathrm{g} $ distributions from PYTHIA6, with each distribution normalized to unity. The top right and lower panels compare the sum of the contributions in PYTHIA6 and HERWIG++ to data, where the parton type breakdown is determined from PYTHIA6. Only statistical uncertainties are shown. |
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Figure 2-a:
Distribution of the $Q^\kappa $ jet charge, for leading jets and $\kappa =$ 0.6, in data (points) and MC simulations. The figure compares the data with the $\mathrm{u} $, $\mathrm{d} $, and $\mathrm{g} $ distributions from PYTHIA6, with each distribution normalized to unity. Only statistical uncertainties are shown. |
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Figure 2-b:
Distribution of the $Q^\kappa $ jet charge, for leading jets and $\kappa =$ 0.6, in data (points) and MC simulations. The figure compares the sum of the contributions in PYTHIA6 and HERWIG++ to data, where the parton type breakdown is determined from PYTHIA6. Only statistical uncertainties are shown. |
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Figure 2-c:
Distribution of the $Q_{L}^\kappa $ jet charge, for leading jets and $\kappa =$ 0.6, in data (points) and MC simulations. The figure compares the sum of the contributions in PYTHIA6 and HERWIG++ to data, where the parton type breakdown is determined from PYTHIA6. Only statistical uncertainties are shown. |
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Figure 2-d:
Distribution of the $Q_{T}^\kappa $ jet charge, for leading jets and $\kappa =$ 0.6, in data (points) and MC simulations. The figure compares the sum of the contributions in PYTHIA6 and HERWIG++ to data, where the parton type breakdown is determined from PYTHIA6. Only statistical uncertainties are shown. |
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Figure 3:
Dependence on the $ {p_{\mathrm {T}}} $ of the leading jet of the average leading-jet charge $Q^\kappa $ with $\kappa =$ 0.6 in PYTHIA6, HERWIG++, and data. Only statistical uncertainties are shown. The error bars for the simulation indicate the uncertainty from statistical fluctuations in the MC events. The data points are shown in the center of each jet $ {p_{\mathrm {T}}} $ bin (400, 450, 500, 550, 600, 650, 750, 850, 1000, 1500 GeV). |
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Figure 4:
Distributions of leading-jet charge $Q^\kappa $ at the reconstructed level and generated levels in PYTHIA6, for (upper left) $\kappa =$ 1.0, (upper right) 0.6, and (bottom) 0.3. |
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Figure 4-a:
Distributions of leading-jet charge $Q^\kappa $ at the reconstructed level and generated levels in PYTHIA6, for $\kappa =$ 1.0. |
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Figure 4-b:
Distributions of leading-jet charge $Q^\kappa $ at the reconstructed level and generated levels in PYTHIA6, for $\kappa =$ 0.6. |
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Figure 4-c:
Distributions of leading-jet charge $Q^\kappa $ at the reconstructed level and generated levels in PYTHIA6, for $\kappa =$ 0.3. |
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Figure 5:
Comparison of unfolded leading-jet charge distributions with predictions from POWHEG + PYTHIA8 ("PH+P8''). The NLO POWHEG prediction with the NLO CT10 PDF set is compared with predictions where initial-state radiation ("No ISR''), final-state radiation ("No FSR''), or multiple-parton interactions ("No MPI'') are disabled in PYTHIA8. A LO POWHEG prediction using the LO CTEQ6L1 PDF set ("LO'') is also shown. The default jet charge definition ($Q^\kappa $), the longitudinal jet charge definition ($Q_{L}^\kappa $), and the transverse jet charge definition ($Q_{T}^\kappa $) are shown for $\kappa =$ 0.6. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below each plot with two different vertical scales. |
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Figure 5-a:
Comparison of unfolded leading-jet charge distributions with predictions from POWHEG + PYTHIA8 ("PH+P8''). The NLO POWHEG prediction with the NLO CT10 PDF set is compared with predictions where initial-state radiation ("No ISR''), final-state radiation ("No FSR''), or multiple-parton interactions ("No MPI'') are disabled in PYTHIA8. A LO POWHEG prediction using the LO CTEQ6L1 PDF set ("LO'') is also shown. The default jet charge definition ($Q^\kappa $) is shown for $\kappa =$ 0.6. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. |
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Figure 5-b:
Comparison of unfolded leading-jet charge distributions with predictions from POWHEG + PYTHIA8 ("PH+P8''). The NLO POWHEG prediction with the NLO CT10 PDF set is compared with predictions where initial-state radiation ("No ISR''), final-state radiation ("No FSR''), or multiple-parton interactions ("No MPI'') are disabled in PYTHIA8. A LO POWHEG prediction using the LO CTEQ6L1 PDF set ("LO'') is also shown. The longitudinal jet charge definition ($Q_{L}^\kappa $) is shown for $\kappa =$ 0.6. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. |
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Figure 5-c:
Comparison of unfolded leading-jet charge distributions with predictions from POWHEG + PYTHIA8 ("PH+P8''). The NLO POWHEG prediction with the NLO CT10 PDF set is compared with predictions where initial-state radiation ("No ISR''), final-state radiation ("No FSR''), or multiple-parton interactions ("No MPI'') are disabled in PYTHIA8. A LO POWHEG prediction using the LO CTEQ6L1 PDF set ("LO'') is also shown. The transverse jet charge definition ($Q_{T}^\kappa $) is shown for $\kappa =$ 0.6. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. |
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Figure 6:
Comparison of unfolded leading-jet charge $Q^\kappa $ and $Q_{L}^\kappa $ distributions with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distributions are also compared with the NLO HERAPDF1.5 set ("HERAPDF''). The left column shows the distributions for the default jet charge definition ($Q^\kappa $) with all three different $\kappa $ values, while the right column shows for the longitudinal jet charge definition ($Q_{L}^\kappa $) with all three different values of $\kappa $. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below each plot with two different vertical scales. |
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Figure 6-a:
Comparison of unfolded leading-jet |
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Figure 6-b:
Comparison of unfolded leading-jet longitudinal jet charge $Q_{L}^\kappa $ |
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Figure 6-c:
Comparison of unfolded leading-jet default jet charge definition $Q^\kappa $ distribution with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distributions are also compared with the NLO HERAPDF1.5 set ("HERAPDF'') with $\kappa = $ 0.6. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. |
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Figure 6-d:
Comparison of unfolded leading-jet longitudinal jet charge $Q_{L}^\kappa $ distribution with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distributions are also compared with the NLO HERAPDF1.5 set ("HERAPDF'') with $\kappa = $ 0.6. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. |
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Figure 6-e:
Comparison of unfolded leading-jet default jet charge definition $Q^\kappa $ distribution with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distributions are also compared with the NLO HERAPDF1.5 set ("HERAPDF'') with $\kappa = $ 0.3. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. |
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Figure 6-f:
Comparison of unfolded leading-jet longitudinal jet charge $Q_{L}^\kappa $ distribution with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distributions are also compared with the NLO HERAPDF1.5 set ("HERAPDF'') with $\kappa = $ 0.3. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. |
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Figure 7:
Comparison of unfolded leading-jet charge distributions $Q_{T}^\kappa $ with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators for transverse jet charge definition ($Q_{T}^\kappa $) with all different $\kappa $ values. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distributions are also compared with the NLO HERAPDF1.5 set ("HERAPDF''). Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below each plot with two different vertical scales. |
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Figure 7-a:
Comparison of unfolded leading-jet charge distributions $Q_{T}^\kappa $ with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators for transverse jet charge definition ($Q_{T}^\kappa $) with $\kappa =$ 1.0. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distributions are also compared with the NLO HERAPDF1.5 set ("HERAPDF''). Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below each plot with two different vertical scales. |
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Figure 7-b:
Comparison of unfolded leading-jet charge distributions $Q_{T}^\kappa $ with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators for transverse jet charge definition ($Q_{T}^\kappa $) with $\kappa =$ 0.6. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distributions are also compared with the NLO HERAPDF1.5 set ("HERAPDF''). Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below each plot with two different vertical scales. |
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Figure 7-c:
Comparison of unfolded leading-jet charge distributions $Q_{T}^\kappa $ with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators for transverse jet charge definition ($Q_{T}^\kappa $) with $\kappa =$ 0.3. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distributions are also compared with the NLO HERAPDF1.5 set ("HERAPDF''). Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below each plot with two different vertical scales. |
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Figure 8:
Comparison of unfolded leading-jet charge distributions $Q^\kappa $ and $Q_{L}^\kappa $ with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators in 3 ranges of leading-jet $ {p_{\mathrm {T}}} $. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distributions are also compared with the NLO HERAPDF1.5 set ("HERAPDF''). The left column shows the jet $ {p_{\mathrm {T}}} $ dependence for the default jet charge definition ($Q^\kappa $) with $\kappa $ = 0.6. The right column shows the jet $ {p_{\mathrm {T}}} $ dependence for the longitudinal jet charge definition ($Q_{L}^\kappa $) with $\kappa $ = 0.6. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below each plot with two different vertical scales. The average jet charge value is quoted on each panel only with statistical uncertainties. |
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Figure 8-a:
Comparison of the unfolded leading-jet default jet charge $Q^\kappa $ distribution with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators in 3 ranges of leading-jet $ {p_{\mathrm {T}}} $. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distribution is also compared with the NLO HERAPDF1.5 set ("HERAPDF'') with $\kappa $ = 0.6 for 400 $ < p_{\mathrm{T} < $ 700 GeV. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. The average jet charge value is quoted only with statistical uncertainties. |
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Figure 8-b:
Comparison of the unfolded leading-jet longitudinal jet charge $Q_{L}^\kappa $ distribution with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators in 3 ranges of leading-jet $ {p_{\mathrm {T}}} $. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distribution is also compared with the NLO HERAPDF1.5 set ("HERAPDF'') with $\kappa $ = 0.6 for 400 $ < p_{\mathrm{T} < $ 700 GeV. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. The average jet charge value is quoted only with statistical uncertainties. |
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Figure 8-c:
Comparison of the unfolded leading-jet default jet charge $Q^\kappa $ distribution with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators in 3 ranges of leading-jet $ {p_{\mathrm {T}}} $. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distribution is also compared with the NLO HERAPDF1.5 set ("HERAPDF'') with $\kappa $ = 0.6 for 700 $ < p_{\mathrm{T} < $ 1000 GeV. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. The average jet charge value is quoted only with statistical uncertainties. |
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Figure 8-d:
Comparison of the unfolded leading-jet longitudinal jet charge $Q_{L}^\kappa $ distribution with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators in 3 ranges of leading-jet $ {p_{\mathrm {T}}} $. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distribution is also compared with the NLO HERAPDF1.5 set ("HERAPDF'') with $\kappa $ = 0.6 for the 700 $ < p_{\mathrm{T} < $ 1000 GeV. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. The average jet charge value is quoted only with statistical uncertainties. |
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Figure 8-e:
Comparison of the unfolded leading-jet default jet charge $Q^\kappa $ distribution with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators in 3 ranges of leading-jet $ {p_{\mathrm {T}}} $. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distribution is also compared with the NLO HERAPDF1.5 set ("HERAPDF'') with $\kappa $ = 0.6 for the 1000 $ < p_{\mathrm{T} < $ 1800 GeV. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. The average jet charge value is quoted only with statistical uncertainties. |
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Figure 8-f:
Comparison of the unfolded leading-jet longitudinal jet charge $Q_{L}^\kappa $ distribution with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators in 3 ranges of leading-jet $ {p_{\mathrm {T}}} $. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distribution is also compared with the NLO HERAPDF1.5 set ("HERAPDF'') with $\kappa $ = 0.6 for 1000 $ < p_{\mathrm{T} < $ 1800 GeV. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. The average jet charge value is quoted only with statistical uncertainties. |
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Figure 9:
Comparison of unfolded leading-jet charge distributions $Q_{T}^\kappa $ with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators in 3 ranges of leading-jet $ {p_{\mathrm {T}}} $ for the transverse jet charge definition ($Q_{T}^\kappa $) with $\kappa = $ 0.6. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distributions are also compared with the NLO HERAPDF1.5 set ("HERAPDF''). Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below each plot with two different vertical scales. The average jet charge value is quoted on each panel only with statistical uncertainties. |
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Figure 9-a:
Comparison of unfolded leading-jet transverse jet charge $Q_{T}^\kappa $ distribution with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators in the range 400 $ < p_{\mathrm{T} < $ 700 GeV (leading jet) with $\kappa = $ 0.6. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distribution is also compared with the NLO HERAPDF1.5 set ("HERAPDF''). Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. The average jet charge value is quoted on each panel only with statistical uncertainties. |
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Figure 9-b:
Comparison of unfolded leading-jet transverse jet charge $Q_{T}^\kappa $ distribution with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators in the range 700 $ < p_{\mathrm{T} < $ 1000 GeV (leading jet) with $\kappa = $ 0.6. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distribution is also compared with the NLO HERAPDF1.5 set ("HERAPDF''). Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. The average jet charge value is quoted on each panel only with statistical uncertainties. |
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Figure 9-c:
Comparison of unfolded leading-jet transverse jet charge $Q_{T}^\kappa $ distribution with POWHEG + PYTHIA8 ("PH+P8'') and POWHEG + HERWIG++ ("PH+HPP'') generators in the range 1000 $ < p_{\mathrm{T} < $ 1800 GeV (leading jet) with $\kappa = $ 0.6. In addition to the POWHEG + PYTHIA8 predictions with the NLO CT10 PDF set ("CT10''), the distribution is also compared with the NLO HERAPDF1.5 set ("HERAPDF''). Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. The average jet charge value is quoted on each panel only with statistical uncertainties. |
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Figure 10:
Comparison of unfolded leading-jet charge distributions with predictions from POWHEG + PYTHIA8. The NLO POWHEG prediction with the NLO CT10 PDF set is compared with predictions where the $\alpha _{S}$ parameter for final-state radiation in PYTHIA8 is varied from its default value of 0.138. The default jet charge definition ($Q^\kappa $) for $\kappa = $ 0.3, 0.6, 1.0, the longitudinal jet charge definition ($Q_{L}^\kappa $), and the transverse jet charge definition ($Q_{T}^\kappa $) are shown. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below each plot with two different vertical scales. |
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Figure 10-a:
Comparison of the unfolded leading-jet default jet charge $Q^\kappa $ for $\kappa = $ 0.6 with predictions from POWHEG + PYTHIA8. The NLO POWHEG prediction with the NLO CT10 PDF set is compared with predictions where the $\alpha _{S}$ parameter for final-state radiation in PYTHIA8 is varied from its default value of 0.138. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. |
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Figure 10-b :
Comparison of the unfolded leading-jet longitudinal jet charge $Q_{L}^\kappa $ for $\kappa = $ 0.6 with predictions from POWHEG + PYTHIA8. The NLO POWHEG prediction with the NLO CT10 PDF set is compared with predictions where the $\alpha _{S}$ parameter for final-state radiation in PYTHIA8 is varied from its default value of 0.138. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. |
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Figure 10-c:
Comparison of the unfolded leading-jet transverse jet charge definition $Q_{T}^\kappa $ for $\kappa = $ 0.6 distribution with predictions from POWHEG + PYTHIA8. The NLO POWHEG prediction with the NLO CT10 PDF set is compared with predictions where the $\alpha _{S}$ parameter for final-state radiation in PYTHIA8 is varied from its default value of 0.138. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. |
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Figure 10-d:
Comparison of the unfolded leading-jet default jet charge $Q^\kappa $ for $\kappa = $ 0.3 with predictions from POWHEG + PYTHIA8. The NLO POWHEG prediction with the NLO CT10 PDF set is compared with predictions where the $\alpha _{S}$ parameter for final-state radiation in PYTHIA8 is varied from its default value of 0.138. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. |
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Figure 10-e:
Comparison of the unfolded leading-jet default jet charge $Q^\kappa $ for $\kappa = $ 1.0 with predictions from POWHEG + PYTHIA8. The NLO POWHEG prediction with the NLO CT10 PDF set is compared with predictions where the $\alpha _{S}$ parameter for final-state radiation in PYTHIA8 is varied from its default value of 0.138. Hashed uncertainty bands include both statistical and systematic contributions in data, added in quadrature. The ratio of data to simulation is displayed twice below the plot with two different vertical scales. |
Tables | |
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Table 1:
Systematic uncertainties in terms of their corresponding inverse-variance-weighted mean in the fractional deviation as defined in Eq.(4) in percent (%). |
Summary |
This paper presents measurements of jet charge distributions, unfolded for detector effects, with dijet events collected in proton-proton collisions at $ \sqrt{s} = $ 8 TeV corresponding to an integrated luminosity of 19.7 fb$^{-1}$. Distributions of the leading-jet charge are obtained for three ranges of leading-jet $ p_{\mathrm{T}} $ and for three definitions of jet charge. These three definitions of jet charge provide different sensitivities to parton fragmentation. Three choices for the $\kappa$ parameter are considered, which provide different sensitivities to the softer and harder particles in the jet. The variation of the jet charge with leading-jet $ p_{\mathrm{T}} $ is sensitive to the quark and gluon jet content in the dijet sample. In general, the predictions from POWHEG + PYTHIA8 and POWHEG + HERWIG++ generators show only mild discrepancies with the data distributions. Nevertheless, the differences between the predictions from POWHEG + PYTHIA8 and POWHEG + HERWIG++ can be reduced with the help of these measurements. |
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Compact Muon Solenoid LHC, CERN |