CMS logoCMS event Hgg
Compact Muon Solenoid
LHC, CERN

CMS-HIN-23-001 ; CERN-EP-2024-073
Girth and groomed radius of jets recoiling against isolated photons in lead-lead and proton-proton collisions at $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 5.02 TeV
Submitted to Phys. Lett. B
Abstract: This Letter presents the first measurements of the groomed jet radius $ R_{\mathrm{g}} $ and the jet girth $ g $ in events with an isolated photon recoiling against a jet in lead-lead (PbPb) and proton-proton (pp) collisions at the LHC at a nucleon-nucleon center-of-mass energy of 5.02 TeV. The observables $ R_{\mathrm{g}} $ and $ g $ provide a quantitative measure of how narrow or broad a jet is. The analysis uses PbPb and pp data samples with integrated luminosities of 1.7 nb$^{-1}$ and 301 pb$^{-1}$, respectively, collected with the CMS experiment in 2018 and 2017. Events are required to have a photon with transverse momentum $ p_{\mathrm{T}}^{\gamma} > $ 100 GeV and at least one jet back-to-back in azimuth with respect to the photon and with transverse momentum $ p_{\mathrm{T}}^{\text{jet}} $ such that $ p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.4. The measured $ R_{\mathrm{g}} $ and $ g $ distributions are unfolded to the particle level, which facilitates the comparison between the PbPb and pp results and with theoretical predictions. It is found that jets with $ p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.8, i.e.,, those that closely balance the photon $ p_{\mathrm{T}}^{\gamma} $, are narrower in PbPb than in pp collisions. Relaxing the selection to include jets with $ p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.4 reduces the narrowing of the angular structure of jets in PbPb relative to the pp reference. This shows that selection bias effects associated with jet energy loss play an important role in the interpretation of jet substructure measurements.
Figures & Tables Summary References CMS Publications
Figures

png pdf
Figure 1:
Schematic diagram of the potential selection bias due to jet energy loss that may occur when selecting jets based on the their $ p_{\mathrm{T}} $. Broader structures are expected to be more quenched (red line, thicker arrow), whereas narrower structures are expected to be quenched less (blue line, thinner arrow). Combined with the steeply falling jet $ p_{\mathrm{T}} $ spectrum, this can lead to a preferential selection of narrow jets in a given jet $ p_{\mathrm{T}} $ interval, as indicated by the vertical rectangular box. The dashed curve represents the jet $ p_{\mathrm{T}} $ spectrum in the absence of medium-induced jet modifications.

png pdf
Figure 2:
Unfolded distributions of jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.4. The upper panels show the comparison of the observable in pp collisions and predictions from simulated events. The lower panels show the corresponding ratios of the MC calculations and data. The bands represent the total uncertainties, whereas the vertical bars represent the statistical uncertainties.

png pdf
Figure 2-a:
Unfolded distributions of jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.4. The upper panels show the comparison of the observable in pp collisions and predictions from simulated events. The lower panels show the corresponding ratios of the MC calculations and data. The bands represent the total uncertainties, whereas the vertical bars represent the statistical uncertainties.

png pdf
Figure 2-b:
Unfolded distributions of jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.4. The upper panels show the comparison of the observable in pp collisions and predictions from simulated events. The lower panels show the corresponding ratios of the MC calculations and data. The bands represent the total uncertainties, whereas the vertical bars represent the statistical uncertainties.

png pdf
Figure 3:
Unfolded distributions of jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.8. The upper panels show the comparison of the observable in pp collisions and predictions from simulated events. The lower panels show the corresponding ratios of the MC calculations and data. The bands represent the total experimental uncertainties, whereas the vertical bars represent the statistical uncertainties.

png pdf
Figure 3-a:
Unfolded distributions of jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.8. The upper panels show the comparison of the observable in pp collisions and predictions from simulated events. The lower panels show the corresponding ratios of the MC calculations and data. The bands represent the total experimental uncertainties, whereas the vertical bars represent the statistical uncertainties.

png pdf
Figure 3-b:
Unfolded distributions of jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.8. The upper panels show the comparison of the observable in pp collisions and predictions from simulated events. The lower panels show the corresponding ratios of the MC calculations and data. The bands represent the total experimental uncertainties, whereas the vertical bars represent the statistical uncertainties.

png pdf
Figure 4:
Unfolded distributions of jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.4 (selecting both more and less quenched jets). The bands represent the total uncertainties, whereas the vertical bars represent the statistical uncertainties.

png pdf
Figure 4-a:
Unfolded distributions of jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.4 (selecting both more and less quenched jets). The bands represent the total uncertainties, whereas the vertical bars represent the statistical uncertainties.

png pdf
Figure 4-b:
Unfolded distributions of jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.4 (selecting both more and less quenched jets). The bands represent the total uncertainties, whereas the vertical bars represent the statistical uncertainties.

png pdf
Figure 5:
Unfolded distributions of jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.8 (selecting less quenched jets). The bands represent the total uncertainties, whereas the vertical bars represent the statistical uncertainties.

png pdf
Figure 5-a:
Unfolded distributions of jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.8 (selecting less quenched jets). The bands represent the total uncertainties, whereas the vertical bars represent the statistical uncertainties.

png pdf
Figure 5-b:
Unfolded distributions of jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.8 (selecting less quenched jets). The bands represent the total uncertainties, whereas the vertical bars represent the statistical uncertainties.

png pdf
Figure 6:
Ratio of the normalized yields of PbPb to pp data for jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.4 (selecting both more and less quenched jets). The data are compared with the hybrid model predictions for $ L_{\text{res}} = $ 0 (upper) and for nonzero values of $ L_{\text{res}} $ without elastic scattering (lower). The bands around the data points represent the total experimental uncertainties, whereas the vertical bars represent the statistical uncertainties. The uncertainties in the PbPb-to-pp ratio have been obtained assuming the PbPb and pp measurements are uncorrelated. The bands around the theory predictions represent the statistical uncertainties of the prediction.

png pdf
Figure 6-a:
Ratio of the normalized yields of PbPb to pp data for jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.4 (selecting both more and less quenched jets). The data are compared with the hybrid model predictions for $ L_{\text{res}} = $ 0 (upper) and for nonzero values of $ L_{\text{res}} $ without elastic scattering (lower). The bands around the data points represent the total experimental uncertainties, whereas the vertical bars represent the statistical uncertainties. The uncertainties in the PbPb-to-pp ratio have been obtained assuming the PbPb and pp measurements are uncorrelated. The bands around the theory predictions represent the statistical uncertainties of the prediction.

png pdf
Figure 6-b:
Ratio of the normalized yields of PbPb to pp data for jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.4 (selecting both more and less quenched jets). The data are compared with the hybrid model predictions for $ L_{\text{res}} = $ 0 (upper) and for nonzero values of $ L_{\text{res}} $ without elastic scattering (lower). The bands around the data points represent the total experimental uncertainties, whereas the vertical bars represent the statistical uncertainties. The uncertainties in the PbPb-to-pp ratio have been obtained assuming the PbPb and pp measurements are uncorrelated. The bands around the theory predictions represent the statistical uncertainties of the prediction.

png pdf
Figure 6-c:
Ratio of the normalized yields of PbPb to pp data for jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.4 (selecting both more and less quenched jets). The data are compared with the hybrid model predictions for $ L_{\text{res}} = $ 0 (upper) and for nonzero values of $ L_{\text{res}} $ without elastic scattering (lower). The bands around the data points represent the total experimental uncertainties, whereas the vertical bars represent the statistical uncertainties. The uncertainties in the PbPb-to-pp ratio have been obtained assuming the PbPb and pp measurements are uncorrelated. The bands around the theory predictions represent the statistical uncertainties of the prediction.

png pdf
Figure 6-d:
Ratio of the normalized yields of PbPb to pp data for jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.4 (selecting both more and less quenched jets). The data are compared with the hybrid model predictions for $ L_{\text{res}} = $ 0 (upper) and for nonzero values of $ L_{\text{res}} $ without elastic scattering (lower). The bands around the data points represent the total experimental uncertainties, whereas the vertical bars represent the statistical uncertainties. The uncertainties in the PbPb-to-pp ratio have been obtained assuming the PbPb and pp measurements are uncorrelated. The bands around the theory predictions represent the statistical uncertainties of the prediction.

png pdf
Figure 7:
Ratio of the normalized yields of PbPb to pp for jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.8 (selecting less quenched jets). The data are compared with the hybrid predictions for $ L_{\text{res}} = $ 0 (upper) and nonzero values of $ L_{\text{res}} $ without elastic scatterings (lower). The bands around the data points represent the total experimental uncertainties, whereas the vertical bars represent the statistical uncertainties. The uncertainties in the PbPb-to-pp ratio have been obtained assuming the PbPb and pp measurements are uncorrelated. The bands around the theory predictions represent the statistical uncertainties of the prediction.

png pdf
Figure 7-a:
Ratio of the normalized yields of PbPb to pp for jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.8 (selecting less quenched jets). The data are compared with the hybrid predictions for $ L_{\text{res}} = $ 0 (upper) and nonzero values of $ L_{\text{res}} $ without elastic scatterings (lower). The bands around the data points represent the total experimental uncertainties, whereas the vertical bars represent the statistical uncertainties. The uncertainties in the PbPb-to-pp ratio have been obtained assuming the PbPb and pp measurements are uncorrelated. The bands around the theory predictions represent the statistical uncertainties of the prediction.

png pdf
Figure 7-b:
Ratio of the normalized yields of PbPb to pp for jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.8 (selecting less quenched jets). The data are compared with the hybrid predictions for $ L_{\text{res}} = $ 0 (upper) and nonzero values of $ L_{\text{res}} $ without elastic scatterings (lower). The bands around the data points represent the total experimental uncertainties, whereas the vertical bars represent the statistical uncertainties. The uncertainties in the PbPb-to-pp ratio have been obtained assuming the PbPb and pp measurements are uncorrelated. The bands around the theory predictions represent the statistical uncertainties of the prediction.

png pdf
Figure 7-c:
Ratio of the normalized yields of PbPb to pp for jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.8 (selecting less quenched jets). The data are compared with the hybrid predictions for $ L_{\text{res}} = $ 0 (upper) and nonzero values of $ L_{\text{res}} $ without elastic scatterings (lower). The bands around the data points represent the total experimental uncertainties, whereas the vertical bars represent the statistical uncertainties. The uncertainties in the PbPb-to-pp ratio have been obtained assuming the PbPb and pp measurements are uncorrelated. The bands around the theory predictions represent the statistical uncertainties of the prediction.

png pdf
Figure 7-d:
Ratio of the normalized yields of PbPb to pp for jet girth $ g $ (left) and groomed jet radius $ R_{\mathrm{g}} $ (right) of photon-tagged jets in PbPb and pp collisions for $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.8 (selecting less quenched jets). The data are compared with the hybrid predictions for $ L_{\text{res}} = $ 0 (upper) and nonzero values of $ L_{\text{res}} $ without elastic scatterings (lower). The bands around the data points represent the total experimental uncertainties, whereas the vertical bars represent the statistical uncertainties. The uncertainties in the PbPb-to-pp ratio have been obtained assuming the PbPb and pp measurements are uncorrelated. The bands around the theory predictions represent the statistical uncertainties of the prediction.
Tables

png pdf
Table 1:
Summary of bin-by-bin percentual relative uncertainties for $ x_{\gamma \mathrm{j}} > $ 0.4.

png pdf
Table 2:
Summary of bin-by-bin percentual relative uncertainties for $ x_{\gamma \mathrm{j}} > $ 0.8.
Summary
In summary, we report the first measurements girth $ g $ and the groomed jet radius $ R_{\mathrm{g}} $ of jets recoiling against isolated photons in lead-lead (PbPb) and proton-proton (pp) collisions. The analysis uses PbPb and pp collision data, both at a nucleon-nucleon center-of-mass energy of 5.02 TeV. The distributions are unfolded to the particle level in order to facilitate comparisons between experiments and with theoretical predictions. The transverse momentum $ p_{\mathrm{T}} $ of isolated photons ($ p_{\mathrm{T}}^{\gamma} $) can be used as a proxy for the $ p_{\mathrm{T}} $ of the high-virtuality parton that initiates the shower of the recoiling jet. This enables the disentanglement of the potential modification of the momentum and angular substructure of jets due to the interactions with the medium from the selection bias effects that can originate from jet energy loss. This is done using the transverse momentum imbalance, defined as the ratio of the hardest recoil jet $ p_{\mathrm{T}} $ ($ p_{\mathrm{T}}^{\text{jet}} $) and $ p_{\mathrm{T}}^{\gamma} $, $ x_{\gamma \mathrm{j}} \equiv p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} $. It is found that jets with $ p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.8, i.e.,, those that closely balance the photon $ p_{\mathrm{T}}^{\gamma} $, are narrower in PbPb than in pp collisions. Relaxing the selection to include jets with $ p_{\mathrm{T}}^{\text{jet}}/p_{\mathrm{T}}^{\gamma} > $ 0.4 reduces the narrowing of the angular structure of jets in PbPb relative to the pp reference. These observations suggest that selection bias effects play an important role in the interpretation of the modification of the angular scales of jets in terms of medium-induced effects. The measured distributions are compared with calculations based on a hybrid strong and weak coupling model to describe medium-induced jet modifications. According to model predictions, the $ R_{\mathrm{g}} $ and $ g $ distributions are not very sensitive to medium response effects or to variations of the medium resolution length. However, changes in the modeling of Moli\`ere elastic scatterings have an effect of 10--40% at large values of $ g $ and $ R_{\mathrm{g}} $. This shows the ability of the data to constrain the impact of Moli\`ere scatterings in a way that is effectively factorized from the effects of the wake and the medium resolution length. Medium-induced jet modifications are commonly assessed by comparing jets and their substructure at the same reconstructed $ p_{\mathrm{T}} $ in PbPb and pp collisions, which in the former case corresponds to the momentum of the jet after its interactions with the quark gluon plasma. These interactions are expected to broaden the jet and reduce its energy. Thus, in an inclusive jet measurement, when comparing populations of jets in PbPb and pp within the same measured jet $ p_{\mathrm{T}} $ window, a selection bias can lead to an effective narrowing of the angular structure of jets in PbPb relative to pp. One possibility is that the population of jets that were initially broader (hence, more strongly quenched jets) has migrated to lower jet energies, whereas the population of narrower jets (less strongly quenched jets) remains. Thus, events with high-$ p_{\mathrm{T}} $ jets recoiling against energetic isolated photons can be used to better constrain genuine medium modifications of the jet shower, complementing measurements in inclusive jet production.
References
1 W. Busza, K. Rajagopal, and W. van der Schee Heavy ion collisions: the big picture and the big questions Ann. Rev. Nucl. Part. Sci. 68 (2018) 339 1802.04801
2 A. Adams et al. Strongly correlated quantum fluids: ultracold quantum gases, quantum chromodynamic plasmas, and holographic duality New J. Phys. 14 (2012) 115009 1205.5180
3 J. D. Bjorken Highly relativistic nucleus-nucleus collisions: the central rapidity region PRD 27 (1983) 140
4 G.-Y. Qin and X.-N. Wang Jet quenching in high-energy heavy ion collisions Int. J. Mod. Phys. E 24 (2015) 1530014 1511.00790
5 J.-P. Blaizot and Y. Mehtar-Tani Jet structure in heavy ion collisions Int. J. Mod. Phys. E 24 (2015) 1530012 1503.05958
6 J. Casalderrey-Solana and C. A. Salgado Introductory lectures on jet quenching in heavy ion collisions Acta Phys. Polon. B 38 (2007) 3731 0712.3443
7 M. Gyulassy and M. Plumer Jet quenching in dense matter PLB 243 (1990) 432
8 R. Baier et al. Radiative energy loss of high-energy quarks and gluons in a finite volume quark-gluon plasma NPB 483 (1997) 291 hep-ph/9607355
9 R. Baier et al. Radiative energy loss and $ p_{\mathrm{T}} $ broadening of high-energy partons in nuclei NPB 484 (1997) 265 hep-ph/9608322
10 J. Casalderrey-Solana and E. Iancu Interference effects in medium-induced gluon radiation JHEP 08 (2011) 015 1105.1760
11 Y. Mehtar-Tani, C. A. Salgado, and K. Tywoniuk Anti-angular ordering of gluon radiation in QCD media PRL 106 (2011) 122002 1009.2965
12 J. Casalderrey-Solana, Y. Mehtar-Tani, C. A. Salgado, and K. Tywoniuk New picture of jet quenching dictated by color coherence PLB 725 (2013) 357 1210.7765
13 F. D'Eramo, M. Lekaveckas, H. Liu, and K. Rajagopal Momentum broadening in weakly coupled quark-gluon plasma (with a view to finding the quasiparticles within liquid quark-gluon plasma) JHEP 05 (2013) 031 1211.1922
14 F. D'Eramo, K. Rajagopal, and Y. Yin Moli\`ere scattering in quark-gluon plasma: finding point-like scatterers in a liquid JHEP 01 (2019) 172 1808.03250
15 CMS Collaboration Observation and studies of jet quenching in PbPb collisions at nucleon-nucleon center-of-mass energy $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 2.76 TeV Phys. Rev. C 84 (2011) 024906 CMS-HIN-10-004
1102.1957
16 CMS Collaboration First measurement of large area jet transverse momentum spectra in heavy ion collisions JHEP 05 (2021) 284 CMS-HIN-18-014
2102.13080
17 CMS Collaboration Study of jet quenching with isolated-photon+jet correlations in PbPb and pp collisions at $ \sqrt{s_{_{\mathrm{NN}}}} = $ 5.02 TeV PLB 785 (2018) 14 CMS-HIN-16-002
1711.09738
18 CMS Collaboration Measurement of the Splitting Function in $ pp $ and Pb-Pb Collisions at $ \sqrt{s_{_{\mathrm{NN}}}} = $ 5.02 TeV PRL 120 (2018) 142302 CMS-HIN-16-006
1708.09429
19 ALICE Collaboration Measurement of jet quenching with semi-inclusive hadron-jet distributions in central PbPb collisions at $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}}= $ 2.76 TeV JHEP 09 (2015) 170 1506.03984
20 ALICE Collaboration Measurements of inclusive jet spectra in pp and central PbPb collisions at $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}}= $ 5.02 TeV Phys. Rev. C 101 (2020) 034911 1909.09718
21 ALICE Collaboration Exploration of jet substructure using iterative declustering in pp and PbPb collisions at LHC energies PLB 802 (2020) 135227 1905.02512
22 ALICE Collaboration Medium modification of the shape of small-radius jets in central PbPb collisions at $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 2.76 TeV JHEP 10 (2018) 139 1807.06854
23 ATLAS Collaboration Measurement of jet fragmentation in PbPb and pp collisions at $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 5.02 TeV with the ATLAS detector Phys. Rev. C 98 (2018) 024908 1805.05424
24 ATLAS Collaboration Measurement of photon-jet transverse momentum correlations in 5.02 TeV PbPb and pp collisions with ATLAS PLB 789 (2019) 167 1809.07280
25 ATLAS Collaboration Comparison of fragmentation functions for jets dominated by light quarks and gluons from pp and PbPb collisions in ATLAS PRL 123 (2019) 042001 1902.10007
26 STAR Collaboration Measurement of groomed jet substructure observables in pp collisions at $ \sqrt{s} = $ 200 GeV with STAR PLB 811 (2020) 135846 2003.02114
27 STAR Collaboration Differential measurements of jet substructure and partonic energy loss in AuAu collisions at $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 200 GeV Phys. Rev. C 105 (2022) 044906 2109.09793
28 L. Apolinário, Y.-J. Lee, and M. Winn Heavy quarks and jets as probes of the QGP Prog. Part. Nucl. Phys. 127 (2022) 103990 2203.16352
29 L. Cunqueiro and A. M. Sickles Studying the QGP with jets at the LHC and RHIC Prog. Part. Nucl. Phys. 124 (2022) 103940 2110.14490
30 J. M. Butterworth, A. R. Davison, M. Rubin, and G. P. Salam Jet substructure as a new Higgs search channel at the LHC PRL 100 (2008) 242001 0802.2470
31 A. J. Larkoski, S. Marzani, G. Soyez, and J. Thaler Soft drop JHEP 05 (2014) 146 1402.2657
32 A. J. Larkoski, D. Neill, and J. Thaler Jet shapes with the broadening axis JHEP 04 (2014) 017 1401.2158
33 Y. Mehtar-Tani and K. Tywoniuk Groomed jets in heavy ion collisions: sensitivity to medium-induced bremsstrahlung JHEP 04 (2017) 125 1610.08930
34 H. A. Andrews et al. Novel tools and observables for jet physics in heavy ion collisions JPG 47 (2020) 065102 1808.03689
35 P. Caucal, E. Iancu, A. H. Mueller, and G. Soyez Vacuum-like jet fragmentation in a dense QCD medium PRL 120 (2018) 232001 1801.09703
36 P. Caucal, A. Soto-Ontoso, and A. Takacs Dynamically groomed jet radius in heavy ion collisions PRD 105 (2022) 114046 2111.14768
37 ALICE Collaboration Measurement of the groomed jet radius and momentum splitting fraction in pp and PbPb collisions at $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 5.02 TeV PRL 128 (2022) 102001 2107.12984
38 ATLAS Collaboration Measurement of substructure-dependent jet suppression in PbPb collisions at 5.02 TeV with the ATLAS detector Phys. Rev. C 107 (2023) 054909 2211.11470
39 J. Brewer, J. G. Milhano, and J. Thaler Sorting out quenched jets PRL 122 (2019) 222301 1812.05111
40 Y.-L. Du, D. Pablos, and K. Tywoniuk Deep learning jet modifications in heavy ion collisions JHEP 21 (2020) 206 2012.07797
41 J. Brewer, Q. Brodsky, and K. Rajagopal Disentangling jet modification in jet simulations and in Z+jet data JHEP 02 (2022) 175 2110.13159
42 CMS Collaboration The production of isolated photons in PbPb and pp collisions at $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 5.02 TeV JHEP 07 (2020) 116 CMS-HIN-18-016
2003.12797
43 ATLAS Collaboration Centrality, rapidity and transverse momentum dependence of isolated prompt photon production in lead-lead collisions at $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 2.76 TeV measured with the ATLAS detector Phys. Rev. C 93 (2016) 034914 1506.08552
44 ALICE Collaboration Direct photon production in PbPb collisions at $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 2.76 TeV PLB 754 (2016) 235 1509.07324
45 STAR Collaboration Direct virtual photon production in AuAu collisions at $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 200 GeV PLB 770 (2017) 451 1607.01447
46 PHENIX Collaboration Centrality dependence of direct photon production in $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 200 GeV AuAu collisions PRL 94 (2005) 232301 nucl-ex/0503003
47 CMS Collaboration Measurement of the differential cross section for isolated prompt photon production in pp collisions at 7 TeV PRD 84 (2011) 052011 CMS-QCD-10-037
1108.2044
48 T. Becher, S. Favrod, and X. Xu QCD anatomy of photon isolation JHEP 01 (2023) 005 2208.01554
49 CMS Collaboration Jet Shapes of Isolated Photon-Tagged Jets in Pb-Pb and pp Collisions at $ \sqrt {\smash [b]{s_{_{\mathrm {NN}}}}} = $ 5.02 TeV PRL 122 (2019) 152001 CMS-HIN-18-006
1809.08602
50 CMS Collaboration Observation of medium-induced modifications of jet fragmentation in PbPb collisions at $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}}= $ 5.02 TeV using isolated photon-tagged jets PRL 121 (2018) 242301 CMS-HIN-16-014
1801.04895
51 W. T. Giele, E. W. N. Glover, and D. A. Kosower Jet investigations using the radial moment PRD 57 (1998) 1878 hep-ph/9706210
52 R. Kunnawalkam Elayavalli and K. C. Zapp Medium response in JEWEL and its impact on jet shape observables in heavy ion collisions JHEP 07 (2017) 141 1707.01539
53 R.-Z. Wan et al. Jet shape modification at LHC energies by JEWEL Chin. Phys. C 43 (2019) 054110 1812.10062
54 CMS Collaboration HEPData record for this analysis link
55 CMS Collaboration CMS luminosity measurement for the 2018 data-taking period at $ \sqrt{s} = $ 13 TeV CMS Physics Analysis Summary, 2019
CMS-PAS-LUM-18-002
CMS-PAS-LUM-18-002
56 CMS Collaboration Luminosity measurement in proton-proton collisions at 5.02 TeV in 2017 at CMS CMS Physics Analysis Summary, 2021
CMS-PAS-LUM-19-001
CMS-PAS-LUM-19-001
57 CMS Collaboration The CMS experiment at the CERN LHC JINST 3 (2008) S08004
58 CMS Collaboration Development of the CMS detector for the CERN LHC Run 3 Submitted to JINST, 2023 CMS-PRF-21-001
2309.05466
59 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
60 CMS Collaboration The CMS trigger system JINST 12 (2017) P01020 CMS-TRG-12-001
1609.02366
61 CMS Collaboration Electron and photon reconstruction and identification with the CMS experiment at the CERN LHC JINST 16 (2021) P05014 CMS-EGM-17-001
2012.06888
62 CMS Collaboration Performance of the CMS muon detector and muon reconstruction with proton-proton collisions at $ \sqrt{s}= $ 13 TeV JINST 13 (2018) P06015 CMS-MUO-16-001
1804.04528
63 CMS Collaboration Description and performance of track and primary-vertex reconstruction with the CMS tracker JINST 9 (2014) P10009 CMS-TRK-11-001
1405.6569
64 CMS Collaboration Particle-flow reconstruction and global event description with the CMS detector JINST 12 (2017) P10003 CMS-PRF-14-001
1706.04965
65 CMS Collaboration Performance of reconstruction and identification of $ \tau $ leptons decaying to hadrons and $ \nu_\tau $ in pp collisions at $ \sqrt{s}= $ 13 TeV JINST 13 (2018) P10005 CMS-TAU-16-003
1809.02816
66 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
67 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
68 C. Loizides, J. Kamin, and D. d'Enterria Improved Monte Carlo Glauber predictions at present and future nuclear colliders Phys. Rev. C 97 (2018) 054910 1710.07098
69 M. Cacciari, G. P. Salam, and G. Soyez The anti-$ k_{\mathrm{T}} $ jet clustering algorithm JHEP 04 (2008) 063 0802.1189
70 P. Berta, M. Spousta, D. W. Miller, and R. Leitner Particle-level pileup subtraction for jets and jet shapes JHEP 06 (2014) 092 1403.3108
71 O. Kodolova, I. Vardanyan, A. Nikitenko, and A. Oulianov The performance of the jet identification and reconstruction in heavy ions collisions with CMS detector EPJC 50 (2007) 117
72 ALICE Collaboration Measurement of event background fluctuations for charged particle jet reconstruction in PbPb collisions at $ \sqrt{\smash[b]{s_{_{\mathrm{NN}}}}} = $ 2.76 TeV JHEP 03 (2012) 053 1201.2423
73 CMS Collaboration Determination of jet energy calibration and transverse momentum resolution in CMS JINST 6 (2011) P11002 CMS-JME-10-011
1107.4277
74 T. Sj$\text ö $strand et al. An introduction to PYTHIA8.2 Comput. Phys. Commun. 191 (2015) 159 1410.3012
75 CMS Collaboration Extraction and validation of a new set of CMS PYTHIA8 tunes from underlying-event measurements EPJC 80 (2020) 4 CMS-GEN-17-001
1903.12179
76 S. Gieseke, P. Stephens, and B. Webber New formalism for QCD parton showers JHEP 12 (2003) 045 hep-ph/0310083
77 NNPDF Collaboration Parton distributions for the LHC Run II JHEP 04 (2015) 040 1410.8849
78 B. R. Webber A QCD model for jet fragmentation including soft gluon interference NPB 238 (1984) 492
79 CMS Collaboration Development and validation of HERWIG 7 tunes from CMS underlying-event measurements EPJC 81 (2021) 312 CMS-GEN-19-001
2011.03422
80 GEANT 4 Collaboration GEANT 4---a simulation toolkit NIM A 506 (2003) 250
81 I. P. Lokhtin and A. M. Snigirev A model of jet quenching in ultrarelativistic heavy ion collisions and high-$ p_{\mathrm{T}} $ hadron spectra at RHIC EPJC 45 (2006) 211 hep-ph/0506189
82 Y. L. Dokshitzer, G. D. Leder, S. Moretti, and B. R. Webber Better jet clustering algorithms JHEP 08 (1997) 001 hep-ph/9707323
83 M. Wobisch and T. Wengler Hadronization corrections to jet cross-sections in deep inelastic scattering in Workshop on Monte Carlo Generators for HERA Physics (Plenary Starting Meeting), 1998 hep-ph/9907280
84 J. Mulligan and M. Ploskon Identifying groomed jet splittings in heavy ion collisions Phys. Rev. C 102 (2020) 044913 2006.01812
85 M. Dasgupta, L. Magnea, and G. P. Salam Nonperturbative QCD effects in jets at hadron colliders JHEP 02 (2008) 055 0712.3014
86 H. Voss, A. Höcker, J. Stelzer, and F. Tegenfeldt TMVA, the toolkit for multivariate data analysis with ROOT in XIth International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT), [PoS(ACAT)040], 2007
link
physics/0703039
87 D. d'Enterria and J. Rojo Quantitative constraints on the gluon distribution function in the proton from collider isolated-photon data NPB 860 (2012) 311 1202.1762
88 G. D'Agostini A multidimensional unfolding method based on Bayes' theorem NIM A 362 (1995) 487
89 T. Adye Unfolding algorithms and tests using RooUnfold in PHYSTAT 2011 Workshop on Statistical Issues Related to Discovery Claims in Search Experiments and Unfolding
PHYSTAT 2011 (2011) 313
1105.1160
90 J. Bellm et al. HERWIG 7.0/ HERWIG++ 3.0 release note EPJC 76 (2016) 196 1512.01178
91 J. Bellm et al. HERWIG 7.2 release note EPJC 80 (2020) 452 1912.06509
92 CMS Collaboration Study of quark and gluon jet substructure in Z+jet and dijet events from pp collisions JHEP 01 (2022) 188 CMS-SMP-20-010
2109.03340
93 W. T. Giele, D. A. Kosower, and P. Z. Skands A simple shower and matching algorithm PRD 78 (2008) 014026 0707.3652
94 S. Höche and S. Prestel The midpoint between dipole and parton showers EPJC 75 (2015) 461 1506.05057
95 A. Gehrmann-De Ridder, T. Gehrmann, and E. W. N. Glover Antenna subtraction at NNLO JHEP 09 (2005) 056 hep-ph/0505111
96 H. Brooks, C. T. Preuss, and P. Skands Sector showers for hadron collisions JHEP 07 (2020) 032 2003.00702
97 S. Catani and M. H. Seymour A general algorithm for calculating jet cross sections in NLO QCD NPB 485 (1997) 291 hep-ph/9605323
98 J. Casalderrey-Solana et al. A hybrid strong/weak coupling approach to jet quenching JHEP 10 (2014) 019 1405.3864
99 P. Skands, S. Carrazza, and J. Rojo Tuning PYTHIA8.1: the Monash 2013 tune EPJC 74 (2014) 3024 1404.5630
100 J. Casalderrey-Solana et al. Jet wake from linearized hydrodynamics JHEP 05 (2021) 230 2010.01140
101 Z. Hulcher, D. Pablos, and K. Rajagopal Resolution effects in the hybrid strong/weak coupling model JHEP 03 (2018) 010 1707.05245
Compact Muon Solenoid
LHC, CERN