CMS logoCMS event Hgg
Compact Muon Solenoid
LHC, CERN

CMS-SMP-22-005 ; CERN-EP-2024-066
Measurement of multijet azimuthal correlations and determination of the strong coupling in proton-proton collisions at $ \sqrt{s}= $ 13 TeV
Submitted to EPJC
Abstract: A measurement is presented of a ratio observable that provides a measure of the azimuthal correlations among jets with large transverse momentum $ p_{\mathrm{T}} $. This observable is measured in multijet events over the range of $ p_{\mathrm{T}} = $ 360-3170 GeV based on data collected by the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 134 fb$ ^{-1} $. The results are compared with predictions from Monte Carlo parton-shower event generator simulations, as well as with fixed-order perturbative quantum chromodynamics (pQCD) predictions at next-to-leading-order (NLO) accuracy obtained with different parton distribution functions (PDFs) and corrected for nonperturbative and electroweak effects. Data and theory agree within uncertainties. From the comparison of the measured observable with the pQCD prediction obtained with the NNPDF3.1 NLO PDFs, the strong coupling at the Z boson mass scale is $ \alpha_\mathrm{S}(m_{\mathrm{Z}})= $ 0.1177 $ \pm $ 0.0013 (exp) $ _{-0.0073}^{+0.0116} $ (theo) $ = $ 0.1177 $_{-0.0074}^{+0.0117} $, where the total uncertainty is dominated by the scale dependence of the fixed-order predictions. A test of the running of $ \alpha_\mathrm{S} $ in the TeV region shows no deviation from the expected NLO pQCD behaviour.
Figures & Tables Summary References CMS Publications
Figures

png pdf
Figure 1:
Example of the number of entries contributing to the numerator and denominator of the $ R_{\Delta\phi}(p_{\mathrm{T}}) $ ratio, Eq. (1), for 2-jet (left) and 3-jet (right) events, with all jets having $ p_{\mathrm{T}} > p_{\text{Tmin}}^{\text{nbr}}= $ 100 GeV. The 2-jet topology does not contribute (null numerator) to the $ R_{\Delta\phi}(p_{\mathrm{T}}) $ ratio when the azimuthal distance for neighbouring jets is fixed to 2 $ \pi/3 < \Delta\phi < 7\pi/ $ 8. In the 3-jet topology, each jet is considered as a reference, and its azimuthal separations ($ \Delta\phi{,} $ 1 and $ \Delta\phi{,} $ 2) to other neighbouring jets (with $ p_{\mathrm {T,1}}^{\text {nbr}} $ and $ p_{\mathrm{T,2}}^{\text {nbr}} $) are computed. Each neighbouring jet with $ \Delta\phi $ within the specified interval increments the entries of the numerator, whereas the denominator simply counts the number of jets in the event.

png pdf
Figure 2:
Probability matrix for the $ N(p_{\mathrm{T}},n) $ distribution built using PYTHIA8 simulated events. The horizontal axis corresponds to the generator-level jet $ p_{\mathrm{T}} $, and the vertical axis to the reconstructed-level jet $ p_{\mathrm{T}} $. The 4 $ \times $ 4 structure of the matrix corresponds to the bins of neighbouring jets $ n $ (labelled in the uppermost row and rightmost column), and indicates migrations among those bins. The horizontal and vertical axes of each cell correspond to the $ p_{\mathrm{T}} $ of the jets, and each cell indicates the migrations among the jet $ p_{\mathrm{T}} $ bins. The range of colours covers from 10$^{-6} $ to 1, and indicates the probability of migrations from a given (generator) particle-level bin to the corresponding (reconstructed) detector-level bin.

png pdf
Figure 3:
Bin-to-bin correlation matrix for the $ R_{\Delta\phi}(p_{\mathrm{T}}) $ distribution at the particle level, where the value 1 ($-$1) corresponds to fully (anti)correlated bins. For illustration purposes, only bins with (anti)correlations larger (smaller) than 0.05 ($-$0.05) are shown also as text.

png pdf
Figure 4:
The $ R_{\Delta\phi}(p_{\mathrm{T}}) $ observable as a function of $ p_{\mathrm{T}} $, compared with MC generator predictions at LO (left) and at NLO (right) accuracy. The LO predictions are obtained with PYTHIA8 tunes CUETP8M1 and CUETP8M2, and HERWIG++ tune UE-EE-5-CTEQ6L1 MC event generators. The NLO predictions are obtained with POWHEG interfaced with each of the aforementioned MC event generators. The experimental data are represented with black dots and the MC predictions with coloured lines. The lower panel of each plot shows the ratio between MC predictions and experimental data. The total experimental uncertainties are indicated by the vertical error bars (upper panels) and coloured band (lower panels) correspondingly.

png pdf
Figure 5:
Theoretical predictions for the cross sections corresponding to the numerator (left) and denominator (right) of the $ R_{\Delta\phi}(p_{\mathrm{T}}) $ ratio, Eq. (1), obtained using the NNPDF3.1 NLO PDF set. The coloured bands represent the LO and NLO scale uncertainties derived with a six-point variation of $ \mu_\mathrm{R} $ and $ \mu_\mathrm{F} $ from the central reference value. The lower panels show the ratios to the respective LO predictions.

png pdf
Figure 6:
Nonperturbative correction factors for the numerator (upper left) and denominator (upper right) of the $ R_{\Delta\phi}(p_{\mathrm{T}}) $ ratio, Eq. (1), using PYTHIA8 with tunes CUETP8M1 and CUETP8M2, HERWIG++ with tune UE-EE-5-CTEQ6L1, and POWHEG interfaced with each of them. The lower plot shows the NP correction factors (blue line) for $ R_{\Delta\phi}(p_{\mathrm{T}}) $ and their uncertainties.

png pdf
Figure 7:
Electroweak corrections for the numerator (blue) and denominator (green) of Eq. (1), and for the $ R_{\Delta\phi}(p_{\mathrm{T}}) $ ratio itself (red). The solid lines correspond to the additive combination of NLO EW corrections to the QCD process (NLO QCD$ \,+\, $EW), and the markers represent the multiplicative combination (NLO QCD$ \,\times\, $EW).

png pdf
Figure 8:
The $ R_{\Delta\phi}(p_{\mathrm{T}}) $ observable as a function of $ p_{\mathrm{T}} $, compared with fixed-order theoretical calculations at NLO accuracy using the ABMP16 (upper left), CT18 (upper right), MSHT20 (lower left), and NNPDF3.1 (lower right) NLO PDF sets. The experimental data are indicated with blue dots (with error bars representing the total experimental uncertainty), the theoretical prediction for the default $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) $ for each PDF set with black solid lines, the scale uncertainties with red bands, and the PDF uncertainties with green bands. The lower panel of each plot shows the ratio between experimental data and theoretical predictions.

png pdf
Figure 9:
Sensitivity of the $ R_{\Delta\phi}(p_{\mathrm{T}}) $ ratio to the strong coupling constant $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) $. The data are indicated with blue dots with error bars representing the total experimental uncertainty. In each plot, the lines represent fixed-order NLO theoretical calculations obtained with ABMP16 (upper left), CT18 (upper right), MSHT20 (lower left) and NNPDF3.1 (lower right) NLO PDF sets. Solid green (red) lines indicate maximum (minimum) values, and dotted black lines intermediate values of $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) $ for each PDF set.

png pdf
Figure 10:
Minimization of the $ \chi^2 $ between experimental measurements and theoretical predictions for the $ R_{\Delta\phi}(p_{\mathrm{T}}) $ ratio, with respect to $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) $ for the ABMP16, CT18, MSHT20, and NNPDF3.1 NLO PDF sets. In this plot, only experimental uncertainties are included in the covariance matrix. The minimum value of $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) $ found for each PDF set is indicated with a dashed line and corresponds to the central result. The experimental uncertainty is estimated from the $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) $ values for which the $ \chi^2 $ is increased by one unit with respect to the minimum value.

png pdf
Figure 11:
Determination of $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) $ from the $ R_{\Delta\phi}(p_{\mathrm{T}}) $ ratio with the NNPDF3.1 PDF set (red), in comparison with previous NLO determinations of $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) $ from inclusive jet (magenta), dijet (green), and multijet (blue) measurements. The horizontal error bars indicate the total uncertainty (experimental and theoretical). The world-average $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) $ value is represented by the vertical dashed black line and its uncertainty by the yellow band.

png pdf
Figure 12:
Running of the strong coupling $ \alpha_\mathrm{S}(Q) $ (dashed line) evolved using the current world-average value $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) = $ 0.1180 $ \pm $ 0.0009 [5] together with its associated total uncertainty (yellow band). The four new extractions from the present analysis (Table 5) are shown as filled red circles, compared with results from the H1[93,94,90], ZEUS [95], D0 [11,12], CMS [14],17,18,22], and ATLAS [24,21] experiments. The vertical error bars indicate the total uncertainty (experimental and theoretical). All the experimental results shown in this figure are based on fixed-order predictions at NLO accuracy in pQCD.
Tables

png pdf
Table 1:
The different HLT $ p_{\mathrm{T}} $ thresholds used in the measurement and the corresponding integrated luminosities for each data-taking year.

png pdf
Table 2:
Values of the $ R_{\Delta\phi}(p_{\mathrm{T}}) $ observable in different $ p_{\mathrm{T}} $ intervals, and associated experimental uncertainties.

png pdf
Table 3:
Default and range of $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) $ values used in the different NLO PDF sets.

png pdf
Table 4:
Results for $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) $, associated uncertainties, and goodness-of-fit per degree of freedom ($ \chi^2/n_\text{dof} $), obtained from the measured $ R_{\Delta\phi}(p_{\mathrm{T}}) $ distribution compared with theoretical predictions using different NLO PDF sets.

png pdf
Table 5:
Values of $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) $ and $ \alpha_\mathrm{S}(Q) $ determined in four different jet $ p_{\mathrm{T}} $ fitting subregions corresponding to an average scale $ \langle Q \rangle $ over each $ p_{\mathrm{T}} $ interval.
Summary
A measurement of the $ R_{\Delta\phi}(p_{\mathrm{T}}) $ ratio, sensitive to azimuthal correlations in multijet events, has been presented using proton-proton collision data collected by the CMS experiment at a centre-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 134 fb$ ^{-1} $. The experimental data are compared with predictions from Monte Carlo (MC) event generators, PYTHIA8 with tunes CUETP8M1 and CUETP8M2, HERWIG++ with tune UE-EE-5-CTEQ6L1, and POWHEG interfaced with each one of them. Deviations between data and MC predictions are observed in all cases, except for PYTHIA8 tune CUETP8M2, which gives a good overall description of the measurement. The measurement is also compared with fixed-order perturbative quantum chromodynamics (pQCD) predictions at next-to-leading-order (NLO) accuracy using the NLOJET++ package within the FASTNLO framework. Those predictions are extracted for four different NLO parton distribution function (PDF) sets, ABMP16, CT18, MSHT20, and NNPDF3.1. Corrections for nonperturbative (NP) effects are evaluated using all the aforementioned MC event generators, and are applied to the fixed-order predictions. The predictions are additionally corrected for electroweak (EW) effects that become important at large jet transverse momenta. Generally, the fixed-order predictions are in agreement with the experimental data in the phase space of this analysis, and they provide a good description of the measured $ R_{\Delta\phi}(p_{\mathrm{T}}) $ distribution for all PDF sets. {\tolerance=2400 Based on a comparison of the measured $ R_{\Delta\phi}(p_{\mathrm{T}}) $ distribution and the theoretical predictions, the strong coupling at the scale of the Z boson mass is: $ \alpha_\mathrm{S}(m_{\mathrm{Z}})= $ 0.1177 $_{-0.0068}^{+0.0114} $ (scale) $ \pm $ 0.0013 (exp) $ \pm $ 0.0011 (NP) $ \pm $ 0.0010 (PDF) $ \pm $ 0.0003 (EW) $ \pm $ 0.0020 (PDF choice) $=$ 0.1177 $_{-0.0074}^{+0.0117} $, using calculations based on the NNPDF3.1 NLO PDF set. Alternative $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) $ results obtained with other PDF sets are compatible among each other, as well as with the central result of this work, and with the current world average, $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) = $ 0.1180 $ \pm $ 0.0009. The spread of the $ \alpha_\mathrm{S}(m_{\mathrm{Z}}) $ values obtained from different PDF sets is used for the assignment of the ``PDF choice'' uncertainty quoted in the final strong coupling constant derived here. The dominant uncertainty in this measurement originates from the scale dependence of the NLO pQCD predictions, and is expected to be significantly reduced with the future inclusion of fixed-order predictions at next-to-NLO accuracy. The evolution of the strong coupling as a function of the energy scale, $ \alpha_\mathrm{S}(Q) $, has been tested up to $ Q\approx $ 2 TeV, a higher scale than that probed in previous H1, ZEUS, D0, CMS, and ATLAS measurements. This test has been performed by choosing as energy scale $ Q $ the average jet transverse momentum in the different intervals considered, and no deviation from the expected NLO pQCD running of the strong coupling is observed.
References
1 C. G. Callan, Jr. Broken scale invariance in scalar field theory PRD 2 (1970) 1541
2 K. Symanzik Small distance behavior in field theory and power counting Commun. Math. Phys. 18 (1970) 227
3 K. Symanzik Small distance behavior analysis and Wilson expansion Commun. Math. Phys. 23 (1971) 49
4 P. A. Baikov, K. G. Chetyrkin, and J. H. K \"u hn Five-loop running of the QCD coupling constant PRL 118 (2017) 082002 1606.08659
5 Particle Data Group , R. L. Workman et al. Review of particle physics Prog. Theor. Exp. Phys. 2022 (2022) 083C01
6 D. d'Enterria et al. The strong coupling constant: State of the art and the decade ahead Submitted to J. Phys. G, 2022 2203.08271
7 CMS Collaboration Precision luminosity measurement in proton-proton collisions at $ \sqrt{s}= $ 13 TeV in 2015 and 2016 at CMS EPJC 81 (2021) 800 CMS-LUM-17-003
2104.01927
8 CMS Collaboration CMS luminosity measurement for the 2017 data-taking period at $ \sqrt{s} = $ 13 TeV CMS Physics Analysis Summary, 2018
link
CMS-PAS-LUM-17-004
9 CMS Collaboration CMS luminosity measurement for the 2018 data-taking period at $ \sqrt{s} = $ 13 TeV CMS Physics Analysis Summary, 2019
link
CMS-PAS-LUM-18-002
10 CDF Collaboration Measurement of the strong coupling constant from inclusive jet production at the Tevatron $ \mathrm{\bar{p}p} $ collider PRL 88 (2002) 042001 hep-ex/0108034
11 D0 Collaboration Determination of the strong coupling constant from the inclusive jet cross section in p$ \bar{\mathrm{p}} $ collisions at $ \sqrt{s} = $ 1.96 TeV PRD 80 (2009) 111107 0911.2710
12 D0 Collaboration Measurement of angular correlations of jets at $ \sqrt{s}= $ 1.96 TeV and determination of the strong coupling at high momentum transfers PLB 718 (2012) 56 1207.4957
13 B. Malaescu and P. Starovoitov Evaluation of the strong coupling constant $ \alpha_s $ using the ATLAS inclusive jet cross-section data EPJC 72 (2012) 2041 1203.5416
14 CMS Collaboration Measurement of the ratio of the inclusive 3-jet cross section to the inclusive 2-jet cross section in pp collisions at $ \sqrt{s} = $ 7 TeV and first determination of the strong coupling constant in the TeV range EPJC 73 (2013) 2604 CMS-QCD-11-003
1304.7498
15 ATLAS Collaboration Measurement of transverse energy-energy correlations in multi-jet events in pp collisions at $ \sqrt{s} = $ 7 TeV using the ATLAS detector and determination of the strong coupling constant $ \alpha_{\mathrm{s}}(m_Z) $ PLB 750 (2015) 427 1508.01579
16 CMS Collaboration Determination of the top-quark pole mass and strong coupling constant from the $ \rm t \bar{t} $ production cross section in pp collisions at $ \sqrt{s} = $ 7 TeV PLB 728 (2014) 496 CMS-TOP-12-022
1307.1907
17 CMS Collaboration Measurement of the inclusive 3-jet production differential cross section in proton-proton collisions at 7 TeV and determination of the strong coupling constant in the TeV range EPJC 75 (2015) 186 CMS-SMP-12-027
1412.1633
18 CMS Collaboration Constraints on parton distribution functions and extraction of the strong coupling constant from the inclusive jet cross section in pp collisions at $ \sqrt{s} = $ 7 TeV EPJC 75 (2015) 288 CMS-SMP-12-028
1410.6765
19 CMS Collaboration Determination of the strong coupling constant $ \alpha_\mathrm{S}(m_\mathrm{Z}) $ from measurements of inclusive $ \mathrm{W}^{\pm} $ and Z boson production cross sections in proton-proton collisions at $ \sqrt{s} = $ 7 and 8 TeV JHEP 06 (2020) 018 CMS-SMP-18-005
1912.04387
20 D. d'Enterria and A. Poldaru Extraction of the strong coupling $ \alpha_\mathrm{S}(m_\mathrm{Z}) $ from a combined NNLO analysis of inclusive electroweak boson cross sections at hadron colliders JHEP 06 (2020) 016 1912.11733
21 ATLAS Collaboration Determination of the strong coupling constant $ \alpha _\mathrm{s} $ from transverse energy-energy correlations in multijet events at $ \sqrt{s} = $ 8 TeV using the ATLAS detector EPJC 77 (2017) 872 1707.02562
22 CMS Collaboration Measurement and QCD analysis of double-differential inclusive jet cross sections in pp collisions at $ \sqrt{s}= $ 8 TeV and cross section ratios to 2.76 and 7 TeV JHEP 03 (2017) 156 CMS-SMP-14-001
1609.05331
23 CMS Collaboration Measurement of the triple-differential dijet cross section in proton-proton collisions at $ \sqrt{s}= $ 8 TeV and constraints on parton distribution functions EPJC 77 (2017) 746 CMS-SMP-16-011
1705.02628
24 ATLAS Collaboration Measurement of dijet azimuthal decorrelations in pp collisions at $ \sqrt{s}= $ 8 TeV with the ATLAS detector and determination of the strong coupling PRD 98 (2018) 092004 1805.04691
25 CMS Collaboration Measurement of jet substructure observables in $ \mathrm{t\overline{t}} $ events from proton-proton collisions at $ \sqrt{s}= $ 13 TeV PRD 98 (2018) 092014 CMS-TOP-17-013
1808.07340
26 CMS Collaboration Measurement of the $ \mathrm{t}\overline{\mathrm{t}} $ production cross section, the top quark mass, and the strong coupling constant using dilepton events in pp collisions at $ \sqrt{s} = $ 13 TeV EPJC 79 (2019) 368 CMS-TOP-17-001
1812.10505
27 CMS Collaboration Measurement of $ \mathrm{t\bar t} $ normalised multi-differential cross sections in pp collisions at $ \sqrt s= $ 13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions EPJC 80 (2020) 658 CMS-TOP-18-004
1904.05237
28 ATLAS Collaboration Determination of the strong coupling constant from transverse energy-energy correlations in multijet events at $ \sqrt{s} = $ 13 TeV with the ATLAS detector JHEP 07 (2023) 085 2301.09351
29 CMS Collaboration Measurement and QCD analysis of double-differential inclusive jet cross sections in proton-proton collisions at $ \sqrt{s} = $ 13 TeV JHEP 02 (2022) 142 CMS-SMP-20-011
2111.10431
30 CMS Collaboration Measurement of multidifferential cross sections for dijet production in proton-proton collisions at $ \sqrt{s} $ = 13 TeV Submitted to EPJC, 2023 CMS-SMP-21-008
2312.16669
31 CMS Collaboration Measurement of energy correlators inside jets and determination of the strong coupling $ \alpha_\mathrm{S}(m_\mathrm{Z}) $ Submitted to Phys. Rev. Lett, 2024 CMS-SMP-22-015
2402.13864
32 CMS Collaboration HEPData record for this analysis link
33 CMS Collaboration The CMS experiment at the CERN LHC JINST 3 (2008) S08004
34 CMS Collaboration Performance of the CMS level-1 trigger in proton-proton collisions at $ \sqrt{s} = $ 13 TeV JINST 15 (2020) P10017 CMS-TRG-17-001
2006.10165
35 CMS Collaboration The CMS trigger system JINST 12 (2017) P01020 CMS-TRG-12-001
1609.02366
36 CMS Collaboration Particle-flow reconstruction and global event description with the CMS detector JINST 12 (2017) P10003 CMS-PRF-14-001
1706.04965
37 CMS Collaboration Technical proposal for the Phase-II upgrade of the Compact Muon Solenoid CMS Technical Proposal CERN-LHCC-2015-010, CMS-TDR-15-02, 2015
CDS
38 M. Cacciari, G. P. Salam, and G. Soyez The anti-$ k_{\mathrm{T}} $ jet clustering algorithm JHEP 04 (2008) 063 0802.1189
39 M. Cacciari, G. P. Salam, and G. Soyez FastJet user manual EPJC 72 (2012) 1896 1111.6097
40 CMS Collaboration Pileup mitigation at CMS in 13 TeV data JINST 15 (2020) P09018 CMS-JME-18-001
2003.00503
41 CMS Collaboration Jet energy scale and resolution in the CMS experiment in pp collisions at 8 TeV JINST 12 (2017) P02014 CMS-JME-13-004
1607.03663
42 CMS Collaboration Jet algorithms performance in 13 TeV data CMS Physics Analysis Summary, 2017
CMS-PAS-JME-16-003
CMS-PAS-JME-16-003
43 CMS Collaboration Performance of missing transverse momentum reconstruction in proton-proton collisions at $ \sqrt{s} = $ 13 TeV using the CMS detector JINST 14 (2019) P07004 CMS-JME-17-001
1903.06078
44 CMS Collaboration Performance of the CMS electromagnetic calorimeter in pp collisions at $ \sqrt{s}= $ 13 TeV Technical Report CERN-EP-2024-014, -003, 2024
CMS-PAS-EGM-18-002
45 T. Sjöstrand et al. An introduction to PYTHIA 8.2 Comput. Phys. Commun. 191 (2015) 159 1410.3012
46 CMS Collaboration Event generator tunes obtained from underlying event and multiparton scattering measurements EPJC 76 (2016) 155 CMS-GEN-14-001
1512.00815
47 CMS Collaboration Extraction and validation of a new set of CMS PYTHIA8 tunes from underlying-event measurements EPJC 80 (2020) 4 CMS-GEN-17-001
1903.12179
48 S. Schmitt TUnfold: an algorithm for correcting migration effects in high energy physics JINST 7 (2012) T10003 1205.6201
49 V. Blobel Unfolding Chapter 6, John Wiley & Sons, Ltd, 2013
link
50 GEANT4 Collaboration GEANT 4---a simulation toolkit NIM A 506 (2003) 250
51 J. Alwall et al. The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations JHEP 07 (2014) 079 1405.0301
52 J. Alwall et al. Comparative study of various algorithms for the merging of parton showers and matrix elements in hadronic collisions EPJC 53 (2008) 473 0706.2569
53 M. Bähr et al. Herwig++ physics and manual EPJC 58 (2008) 639 0803.0883
54 S. Alioli, P. Nason, C. Oleari, and E. Re A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX JHEP 06 (2010) 043 1002.2581
55 C. Bierlich et al. Robust independent validation of experiment and theory: Rivet version 3 SciPost Phys. 8 (2020) 026 1912.05451
56 B. R. Webber A QCD model for jet fragmentation including soft gluon interference NPB 238 (1984) 492
57 M. H. Seymour and A. Siódmok Constraining MPI models using $ \sigma_{\text{eff}} $ and recent Tevatron and LHC underlying event data JHEP 10 (2013) 113 1307.5015
58 D. Stump et al. Inclusive jet production, parton distributions, and the search for new physics JHEP 10 (2003) 046 hep-ph/0303013
59 B. Andersson The Lund model Volume 7, Cambridge University Press, ISBN~978-0-521-01734-3, 978-0-521-4-5, 978-0-511-88149-7, 2005
link
60 NNPDF Collaboration Parton distributions with QED corrections NPB 877 (2013) 290 1308.0598
61 NNPDF Collaboration Unbiased global determination of parton distributions and their uncertainties at NNLO and at LO NPB 855 (2012) 153 1107.2652
62 CMS Collaboration Investigations of the impact of the parton shower tuning in Pythia 8 in the modelling of $ \mathrm{t\overline{t}} $ at $ \sqrt{s}= $ 8 and 13 TeV CMS Physics Analysis Summary, 2016
CMS-PAS-TOP-16-021
CMS-PAS-TOP-16-021
63 NNPDF Collaboration Parton distributions for the LHC Run II JHEP 04 (2015) 040 1410.8849
64 P. Nason A new method for combining NLO QCD with shower Monte Carlo algorithms JHEP 11 (2004) 040 hep-ph/0409146
65 S. Frixione, P. Nason, and C. Oleari Matching NLO QCD computations with parton shower simulations: the POWHEG method JHEP 11 (2007) 070 0709.2092
66 Z. Nagy Three-jet cross sections in hadron-hadron collisions at next-to-leading order PRL 88 (2002) 122003 hep-ph/0110315
67 Z. Nagy Next-to-leading order calculation of three-jet observables in hadron-hadron collision PRD 68 (2003) 094002 hep-ph/0307268
68 T. Kluge, K. Rabbertz, and M. Wobisch FastNLO: Fast pQCD calculations for PDF fits in 14th International Workshop on Deep Inelastic Scattering, 2006
link
hep-ph/0609285
69 D. Britzger, K. Rabbertz, F. Stober, and M. Wobisch New features in version 2 of the fastNLO project fastNLO Collaboration, in 20th International Workshop on Deep-Inelastic Scattering and Related Subjects, 2012
link
1208.3641
70 A. Buckley et al. LHAPDF6: parton density access in the LHC precision era EPJC 75 (2015) 132 1412.7420
71 J. Currie et al. Infrared sensitivity of single jet inclusive production at hadron colliders JHEP 10 (2018) 155 1807.03692
72 M. Czakon, A. Mitov, and R. Poncelet Next-to-next-to-leading order study of three-jet production at the LHC PRL 127 (2021) 152001 2106.05331
73 M. Alvarez et al. NNLO QCD corrections to event shapes at the LHC JHEP 03 (2023) 129 2301.01086
74 M. Cacciari et al. The top-antitop cross-section at 1.8 TeV and 1.96 TeV: A study of the systematics due to parton densities and scale dependence JHEP 04 (2004) 068 hep-ph/0303085
75 S. Catani, D. de Florian, M. Grazzini, and P. Nason Soft gluon resummation for Higgs boson production at hadron colliders JHEP 07 (2003) 028 hep-ph/0306211
76 A. Banfi, G. P. Salam, and G. Zanderighi Phenomenology of event shapes at hadron colliders JHEP 06 (2010) 038 1001.4082
77 S. Alekhin, J. Blümlein, S. Moch, and R. Plačakyté Parton distribution functions, $ \alpha_s $, and heavy-quark masses for LHC Run II PRD 96 (2017) 014011 1701.05838
78 T.-J. Hou et al. New CTEQ global analysis of quantum chromodynamics with high-precision data from the LHC PRD 103 (2021) 014013 1912.10053
79 S. Bailey et al. Parton distributions from LHC, HERA, Tevatron and fixed target data: MSHT20 PDFs EPJC 81 (2021) 341 2012.04684
80 NNPDF Collaboration Parton distributions from high-precision collider data EPJC 77 (2017) 663 1706.00428
81 M. Reyer, M. Schönherr, and S. Schumann Full NLO corrections to 3-jet production and $ \mathbf {R_{32}} $ at the LHC EPJC 79 (2019) 321 1902.01763
82 Sherpa Collaboration Event generation with Sherpa 2.2 SciPost Phys. 7 (2019) 034 1905.09127
83 S. Actis et al. Recursive generation of one-loop amplitudes in the Standard Model JHEP 04 (2013) 037 1211.6316
84 S. Actis et al. RECOLA: REcursive Computation of One-Loop Amplitudes Comput. Phys. Commun. 214 (2017) 140 1605.01090
85 B. Biedermann et al. Automation of NLO QCD and EW corrections with Sherpa and Recola EPJC 77 (2017) 492 1704.05783
86 M. Schönherr An automated subtraction of NLO EW infrared divergences EPJC 78 (2018) 119 1712.07975
87 J. Pumplin et al. Uncertainties of predictions from parton distribution functions. 2. The Hessian method PRD 65 (2001) 014013 hep-ph/0101032
88 W. T. Giele, S. A. Keller, and D. A. Kosower Parton distribution function uncertainties hep-ph/0104052
89 ZEUS Collaboration Jet-radius dependence of inclusive-jet cross-sections in deep inelastic scattering at HERA PLB 649 (2007) 12 hep-ex/0701039
90 H1 Collaboration Measurement of multijet production in ep collisions at high $ Q^2 $ and determination of the strong coupling $ \alpha_s $ EPJC 75 (2015) 65 1406.4709
91 D. Britzger et al. Determination of the strong coupling constant using inclusive jet cross section data from multiple experiments EPJC 79 (2019) 68 1712.00480
92 ZEUS Collaboration Multijet production in neutral current deep inelastic scattering at HERA and determination of $ \alpha_s $ EPJC 44 (2005) 183 hep-ex/0502007
93 H1 Collaboration Jet production in ep collisions at high $ Q^2 $ and determination of $ \alpha_s $ EPJC 65 (2010) 363 0904.3870
94 H1 Collaboration Jet production in ep collisions at low $ Q^2 $ and determination of $ \alpha_s $ EPJC 67 (2010) 1 0911.5678
95 ZEUS Collaboration Inclusive-jet photoproduction at HERA and determination of $ \alpha_s $ NPB 864 (2012) 1 1205.6153
Compact Muon Solenoid
LHC, CERN