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| CMS-EXO-20-002 ; CERN-EP-2021-228 | ||
| Search for a right-handed W boson and a heavy neutrino in proton-proton collisions at $\sqrt{s} = $ 13 TeV | ||
| CMS Collaboration | ||
| 7 December 2021 | ||
| JHEP 04 (2022) 047 | ||
| Abstract: A search is presented for a right-handed W boson (W$_{R}$) and a heavy neutrino (N), in a final state consisting of two same-flavor leptons (ee or $\mu\mu$) and two quarks. The search is performed with the CMS experiment at the CERN LHC using a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 138 fb$^{-1}$ . The search covers two regions of phase space, one where the decay products of the heavy neutrino are merged into a single large-area jet, and one where the decay products are well separated. The expected signal is characterized by an excess in the invariant mass distribution of the final-state objects. No significant excess over the standard model background expectations is observed. The observations are interpreted as upper limits on the product of W$_{R}$ production cross sections and branching fractions assuming that couplings are identical to those of the standard model W boson. For N masses ${m_{{\mathrm{N}} }}$ equal to half the W$_{R}$ mass ${m_{\mathrm{W}_{R}}}$ (${m_{{\mathrm{N}} }} = $ 0.2 TeV), ${m_{\mathrm{W}_{R}}}$ is excluded at 95% confidence level up to 4.7 (4.8) and 5.0 (5.4) TeV for the electron and muon channels, respectively. This analysis provides the most stringent limits on the W$_{R}$ mass to date. | ||
| Links: e-print arXiv:2112.03949 [hep-ex] (PDF) ; CDS record ; inSPIRE record ; HepData record ; CADI line (restricted) ; | ||
| Figures & Tables | Summary | Additional Figures | References | CMS Publications |
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| Figures | |
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Figure 1:
Feynman diagram for the production of a heavy neutrino via the decay of a W$_{R}$ boson. |
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Figure 2:
A schematic diagram of the analysis region. The minimum values of the dilepton mass in the SR and the flavor CR is 400 (200) GeV for the resolved (boosted) region. The backgrounds from tW and ${\mathrm{t} {}\mathrm{\bar{t}}}$ production are estimated from the flavor CR (green), where different flavor (DF) leptons are required. The DY background is estimated from the DY CR (blue). |
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Figure 3:
The ${m_{\ell \ell {\mathrm {j}} {\mathrm {j}}}}$ (${m_{\ell {\mathrm {J}}}}$) distributions in the resolved (boosted) DY CRs are shown in the upper (lower) row. Results in the ee ($\mu \mu $) channels are shown in the left (right) plots. The hatched uncertainty bands on the simulated background histograms include statistical and systematic components. |
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Figure 3-a:
The ${m_{\ell \ell {\mathrm {j}} {\mathrm {j}}}}$ distribution in the resolved DY CRs in the ee channel is shown. The hatched uncertainty bands on the simulated background histograms include statistical and systematic components. |
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Figure 3-b:
The ${m_{\ell \ell {\mathrm {j}} {\mathrm {j}}}}$ distribution in the resolved DY CRs in the $\mu \mu $ channel is shown. The hatched uncertainty bands on the simulated background histograms include statistical and systematic components. |
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Figure 3-c:
The ${m_{\ell {\mathrm {J}}}}$ distribution in the boosted DY CRs in the ee channel is shown. The hatched uncertainty bands on the simulated background histograms include statistical and systematic components. |
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Figure 3-d:
The ${m_{\ell {\mathrm {J}}}}$ distribution in the boosted DY CRs in the $\mu \mu $ channel is shown. The hatched uncertainty bands on the simulated background histograms include statistical and systematic components. |
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Figure 4:
The reconstructed mass of the W$_{R}$ boson in the resolved (upper), boosted with e-jet (lower left), and boosted with $\mu $-jet (lower right) flavor CR. |
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Figure 4-a:
The reconstructed mass of the W$_{R}$ boson in the resolved flavor CR. |
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Figure 4-b:
The reconstructed mass of the W$_{R}$ boson in the boosted with e-jet flavor CR. |
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Figure 4-c:
The reconstructed mass of the W$_{R}$ boson in the boosted with $\mu $-jet flavor CR. |
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Figure 5:
The post-fit ${m_{\ell \ell {\mathrm {j}} {\mathrm {j}}}}$ (${m_{\ell {\mathrm {J}}}}$) distributions in the resolved (boosted) SR are shown in the upper (lower) plot. Results for the dielectron (dimuon) channel are shown on the left (right). Statistical and systematic uncertainties in the expected background yields are represented by the hatched band. The simulated signal distribution is scaled up by a factor of five to enhance visibility. |
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Figure 5-a:
The post-fit ${m_{\ell \ell {\mathrm {j}} {\mathrm {j}}}}$ distribution in the resolved SR for the dielectron channel is shown. Statistical and systematic uncertainties in the expected background yields are represented by the hatched band. The simulated signal distribution is scaled up by a factor of five to enhance visibility. |
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Figure 5-b:
The post-fit ${m_{\ell \ell {\mathrm {j}} {\mathrm {j}}}}$ distribution in the resolved SR for the dimuon channel is shown. Statistical and systematic uncertainties in the expected background yields are represented by the hatched band. The simulated signal distribution is scaled up by a factor of five to enhance visibility. |
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Figure 5-c:
The post-fit ${m_{\ell {\mathrm {J}}}}$ distribution in the boosted SR for the dielectron channel is shown. Statistical and systematic uncertainties in the expected background yields are represented by the hatched band. The simulated signal distribution is scaled up by a factor of five to enhance visibility. |
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Figure 5-d:
The post-fit ${m_{\ell {\mathrm {J}}}}$ distribution in the boosted SR for the dimuon channel is shown. Statistical and systematic uncertainties in the expected background yields are represented by the hatched band. The simulated signal distribution is scaled up by a factor of five to enhance visibility. |
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Figure 6:
The expected (black dashed line) and the observed (black solid line) 95% CL upper limits on the product of the cross section for W$_{R}$ production and the branching fractions for the electron channel (left) and muon channel (right) from the combination of the resolved and boosted categories. The plots in the upper (lower) row are the results for the $ {m_{{\mathrm {N}}}} = {m_{\mathrm{W}_{R}}} /2$ ($ {m_{{\mathrm {N}}}} = $ 0.2 TeV) mass point. The green (inner) and yellow (outer) bands indicate the 68 and 95% coverage of the expected upper limits. The red solid lines represent the values expected from the theory [17]. |
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Figure 6-a:
The expected (black dashed line) and the observed (black solid line) 95% CL upper limits on the product of the cross section for W$_{R}$ production and the branching fractions for the electron channel from the combination of the resolved and boosted categories. The plot is the result for the $ {m_{{\mathrm {N}}}} = {m_{\mathrm{W}_{R}}} /2$ mass point. The green (inner) and yellow (outer) bands indicate the 68 and 95% coverage of the expected upper limits. The red solid lines represent the values expected from the theory [17]. |
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Figure 6-b:
The expected (black dashed line) and the observed (black solid line) 95% CL upper limits on the product of the cross section for W$_{R}$ production and the branching fractions for the muon channel from the combination of the resolved and boosted categories. The plot is the result for the $ {m_{{\mathrm {N}}}} = {m_{\mathrm{W}_{R}}} /2$ mass point. The green (inner) and yellow (outer) bands indicate the 68 and 95% coverage of the expected upper limits. The red solid lines represent the values expected from the theory [17]. |
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Figure 6-c:
The expected (black dashed line) and the observed (black solid line) 95% CL upper limits on the product of the cross section for W$_{R}$ production and the branching fractions for the electron channel from the combination of the resolved and boosted categories. The plot is the result for the $ {m_{{\mathrm {N}}}} = $ 0.2 TeV mass point. The green (inner) and yellow (outer) bands indicate the 68 and 95% coverage of the expected upper limits. The red solid lines represent the values expected from the theory [17]. |
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Figure 6-d:
The expected (black dashed line) and the observed (black solid line) 95% CL upper limits on the product of the cross section for W$_{R}$ production and the branching fractions for the muon channel from the combination of the resolved and boosted categories. The plot is the result for the $ {m_{{\mathrm {N}}}} = $ 0.2 TeV mass point. The green (inner) and yellow (outer) bands indicate the 68 and 95% coverage of the expected upper limits. The red solid lines represent the values expected from the theory [17]. |
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Figure 7:
The observed 95% CL upper limits on the product of the production cross sections and the branching fractions of a right-handed W$_{R}$ boson divided by the theory expectation for a coupling constant ${g_{\mathrm {R}}}$ equal to the SM coupling of the W$_{R}$ boson (${g_{\mathrm {L}}}$), for the electron channel (left) and muon channel (right). The observed exclusion regions are shown for the resolved (solid green), boosted (solid blue), and combined (solid black) channels, together with the expected exclusion region for the combined result (dotted black). The dash-dotted lines represent the 68% coverage of the boundaries of the expected exclusion regions. The observed exclusion regions obtained in the previous search performed by the CMS Collaboration [12] are bounded by the magenta lines. The biggest improvement can be seen in the $ {m_{{\mathrm {N}}}} < $ 0.5 TeV region, where the new boosted category greatly improves the sensitivity over the previous result. |
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Figure 7-a:
The observed 95% CL upper limits on the product of the production cross sections and the branching fractions of a right-handed W$_{R}$ boson divided by the theory expectation for a coupling constant ${g_{\mathrm {R}}}$ equal to the SM coupling of the W$_{R}$ boson (${g_{\mathrm {L}}}$), for the electron channel. The observed exclusion regions are shown for the resolved (solid green), boosted (solid blue), and combined (solid black) channels, together with the expected exclusion region for the combined result (dotted black). The dash-dotted lines represent the 68% coverage of the boundaries of the expected exclusion regions. The observed exclusion regions obtained in the previous search performed by the CMS Collaboration [12] are bounded by the magenta lines. The biggest improvement can be seen in the $ {m_{{\mathrm {N}}}} < $ 0.5 TeV region, where the new boosted category greatly improves the sensitivity over the previous result. |
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Figure 7-b:
The observed 95% CL upper limits on the product of the production cross sections and the branching fractions of a right-handed W$_{R}$ boson divided by the theory expectation for a coupling constant ${g_{\mathrm {R}}}$ equal to the SM coupling of the W$_{R}$ boson (${g_{\mathrm {L}}}$), for the muon channel. The observed exclusion regions are shown for the resolved (solid green), boosted (solid blue), and combined (solid black) channels, together with the expected exclusion region for the combined result (dotted black). The dash-dotted lines represent the 68% coverage of the boundaries of the expected exclusion regions. The observed exclusion regions obtained in the previous search performed by the CMS Collaboration [12] are bounded by the magenta lines. The biggest improvement can be seen in the $ {m_{{\mathrm {N}}}} < $ 0.5 TeV region, where the new boosted category greatly improves the sensitivity over the previous result. |
| Tables | |
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Table 1:
Summary of the relative uncertainties in the total yields of the signal and background (bkgd) predictions. The uncertainties are given for the resolved (boosted) SR. The values for the signal correspond to $ {m_{\mathrm{W}_{R}}} = $ 5 TeV. The range given for each systematic uncertainty source covers the variation across the years and the year-to-year treatment is shown as either fully correlated (C) or uncorrelated (U). The EW1, EW2, and EW3 entries are the uncertainties from the $\mathcal {O}(\alpha ^{2})$ Sudakov terms, the NLO portion of the nNLO EW uncertainty, and the uncertainty in the Sudakov approximation at nNLO, respectively. |
| Summary |
| A search for right-handed bosons (W$_{R}$) and heavy right-handed neutrinos (N) in the left-right symmetric extension of the standard model has been presented. The analysis is based on proton-proton collision data collected at $\sqrt{s} = $ 13 TeV by the CMS detector, corresponding to an integrated luminosity of 138 fb$^{-1}$. The final state consists of events with two same-flavor leptons (ee or $\mu\mu$) and two quarks, and is identified through two regions: the resolved region, where all four objects are well separated, and the boosted region, where the heavy neutrino decay is identified using jet substructure techniques applied to large-area jets. The addition of the boosted region greatly improves the search sensitivity in the region where ${m_{{\mathrm{N}} }} < $ 0.5 TeV. No significant excess over the standard model background expectations is observed in the invariant mass distributions. Upper limits are set on the products of the W$_{R}$ and N production cross sections and their branching fraction to two leptons and two quarks assuming that couplings are identical to those of the standard model. For N masses ${m_{{\mathrm{N}} }}$ equal to half the W$_{R}$ mass ${m_{\mathrm{W}_{R}}}$ (${m_{{\mathrm{N}} }} = $ 0.2 TeV), ${m_{\mathrm{W}_{R}}}$ is excluded at 95% confidence level up to 4.7 (4.8) and 5.0 (5.4) TeV for the electron and muon channels, respectively. This analysis provides the most stringent limits on the W$_{R}$ mass to date. |
| Additional Figures | |
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Additional Figure 1:
The $\mathrm {LSF_{3}}$ distributions of the leading AK8 jet. Data and simulated background from three data periods are compared. Also plotted are the distributions for the simulated signals with $ {m_{{\mathrm {W_R}}}} = $ 5 TeV. The simulated signal distributions are scaled up by a factor of 30 to enhance visibility. The events are required to pass the full electron channel boosted event selection except for the $\mathrm {LSF_{3}}$ requirement. |
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Additional Figure 2:
The $\mathrm {LSF_{3}}$ distributions of the leading AK8 jet. Data and simulated background from three data periods are compared. Also plotted are the distributions for the simulated signals with $ {m_{{\mathrm {W_R}}}} = $ 5 TeV. The simulated signal distributions are scaled up by a factor of 30 to enhance visibility. The events are required to pass the full muon channel boosted event selection except for the $\mathrm {LSF_{3}}$ requirement. |
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Additional Figure 3:
The expected (black dashed line) and the observed (black solid line) 95% CL upper limits on the product of the cross section for W$_R$ production and the branching fractions for the electron channel from the combination of the resolved and boosted categories. The plot is the result for the $ {m_{{\mathrm {N}}}} = $ 0.8 TeV mass point. The green (inner) and yellow (outer) bands indicate the 68 and 95% coverage of the expected upper limits. The red solid line represents the values expected from the theory. |
| References | ||||
| 1 | J. C. Pati and A. Salam | Lepton number as the fourth ``color'' | PRD 10 (1974) 275 | |
| 2 | R. N. Mohapatra and J. C. Pati | A natural left-right symmetry | PRD 11 (1975) 2558 | |
| 3 | G. Senjanović and R. N. Mohapatra | Exact left-right symmetry and spontaneous violation of parity | PRD 12 (1975) 1502 | |
| 4 | W.-Y. Keung and G. Senjanović | Majorana neutrinos and the production of the right-handed charged gauge boson | PRL 50 (1983) 1427 | |
| 5 | R. N. Mohapatra and G. Senjanović | Neutrino mass and spontaneous parity nonconservation | PRL 44 (1980) 912 | |
| 6 | A. Das, P. S. B. Dev, and R. N. Mohapatra | Same sign versus opposite sign dileptons as a probe of low scale seesaw mechanisms | PRD 97 (2018) 015018 | 1709.06553 |
| 7 | M. Gell-Mann, P. Ramond, and R. Slansky | Complex spinors and unified theories | Conf. Proc. C 790927 (1979) 315 | 1306.4669 |
| 8 | ATLAS Collaboration | Search for heavy Majorana neutrinos with the ATLAS detector in pp collisions at $ \sqrt{s}= $ 8 TeV | JHEP 07 (2015) 162 | 1506.06020 |
| 9 | ATLAS Collaboration | Search for heavy Majorana or Dirac neutrinos and right-handed W gauge bosons in final states with two charged leptons and two jets at $ \sqrt{s}= $ 13 TeV with the ATLAS detector | JHEP 01 (2019) 016 | 1809.11105 |
| 10 | ATLAS Collaboration | Search for a right-handed gauge boson decaying into a high-momentum heavy neutrino and a charged lepton in $ pp $ collisions with the ATLAS detector at $ \sqrt{s}= $ 13 TeV | PLB 798 (2019) 134942 | 1904.12679 |
| 11 | CMS Collaboration | Search for heavy neutrinos and W bosons with right-handed couplings in proton-proton collisions at $ \sqrt{s} = $ 8 TeV | EPJC 74 (2014) 3149 | CMS-EXO-13-008 1407.3683 |
| 12 | CMS Collaboration | Search for a heavy right-handed W boson and a heavy neutrino in events with two same-flavor leptons and two jets at $ \sqrt{s}= $ 13 TeV | JHEP 05 (2018) 148 | CMS-EXO-17-011 1803.11116 |
| 13 | CMS Collaboration | Search for heavy Majorana neutrinos in same-sign dilepton channels in proton-proton collisions at $ \sqrt{s}= $ 13 TeV | JHEP 01 (2019) 122 | CMS-EXO-17-028 1806.10905 |
| 14 | CMS Collaboration | Search for heavy neutrinos or third-generation leptoquarks in final states with two hadronically decaying $ \tau $ leptons and two jets in proton-proton collisions at $ \sqrt{s}= $ 13 TeV | JHEP 03 (2017) 077 | CMS-EXO-16-016 1612.01190 |
| 15 | CMS Collaboration | Search for third-generation scalar leptoquarks and heavy right-handed neutrinos in final states with two tau leptons and two jets in proton-proton collisions at $ \sqrt{s}= $ 13 TeV | JHEP 07 (2017) 121 | CMS-EXO-16-023 1703.03995 |
| 16 | A. Ferrari et al. | Sensitivity study for new gauge bosons and right-handed Majorana neutrinos in pp collisions at $ \sqrt{s}= $ 14 TeV | PRD 62 (2000) 013001 | |
| 17 | O. Mattelaer, M. Mitra, and R. Ruiz | Automated neutrino jet and top jet predictions at next-to-leading-order with parton shower matching in effective left-right symmetric models | 2016 | 1610.08985 |
| 18 | M. Mitra, R. Ruiz, D. J. Scott, and M. Spannowsky | Neutrino jets from high-mass W$_\text{R}$ gauge bosons in TeV-scale left-right symmetric models | PRD 94 (2016) 095016 | 1607.03504 |
| 19 | CMS Collaboration | HEPData record for this analysis | link | |
| 20 | CMS Collaboration | The CMS experiment at the CERN LHC | JINST 3 (2008) S08004 | CMS-00-001 |
| 21 | CMS Collaboration | The CMS trigger system | JINST 12 (2017) P01020 | CMS-TRG-12-001 1609.02366 |
| 22 | 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 |
| 23 | 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 |
| 24 | 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 |
| 25 | S. Frixione, P. Nason, and C. Oleari | Matching NLO QCD computations with parton shower simulations: the POWHEG method | JHEP 11 (2007) 070 | 0709.2092 |
| 26 | E. Re | Single-top Wt-channel production matched with parton showers using the POWHEG method | EPJC 71 (2011) 1547 | 1009.2450 |
| 27 | S. Alioli, P. Nason, C. Oleari, and E. Re | NLO single-top production matched with shower in POWHEG: $ s $- and $ t $-channel contributions | JHEP 09 (2009) 111 | 0907.4076 |
| 28 | S. Frixione, G. Ridolfi, and P. Nason | A positive-weight next-to-leading-order Monte Carlo for heavy flavour hadroproduction | JHEP 09 (2007) 126 | 0707.3088 |
| 29 | T. Sjöstrand et al. | An introduction to PYTHIA 8.2 | CPC 191 (2015) 159 | 1410.3012 |
| 30 | CMS Collaboration | Event generator tunes obtained from underlying event and multiparton scattering measurements | EPJC 76 (2016) 155 | CMS-GEN-14-001 1512.00815 |
| 31 | 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 |
| 32 | NNPDF Collaboration | Parton distributions for the LHC Run II | JHEP 04 (2015) 040 | 1410.8849 |
| 33 | NNPDF Collaboration | Parton distributions from high-precision collider data | EPJC 77 (2017) 663 | 1706.00428 |
| 34 | GEANT4 Collaboration | GEANT4--a simulation toolkit | NIMA 506 (2003) 250 | |
| 35 | CMS Collaboration | Measurement of the inelastic proton-proton cross section at $ \sqrt{s}= $ 13 TeV | JHEP 07 (2018) 161 | CMS-FSQ-15-005 1802.02613 |
| 36 | M. Cacciari, G. P. Salam, and G. Soyez | The anti-$ {k_{\mathrm{T}}} $ jet clustering algorithm | JHEP 04 (2008) 063 | 0802.1189 |
| 37 | M. Cacciari, G. P. Salam, and G. Soyez | FastJet user manual | EPJC 72 (2012) 1896 | 1111.6097 |
| 38 | CMS Collaboration | Particle-flow reconstruction and global event description with the CMS detector | JINST 12 (2017) P10003 | CMS-PRF-14-001 1706.04965 |
| 39 | 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 |
| 40 | CMS Collaboration | Jet algorithms performance in 13 TeV data | CMS-PAS-JME-16-003 | CMS-PAS-JME-16-003 |
| 41 | D. Bertolini, P. Harris, M. Low, and N. Tran | Pileup per particle identification | JHEP 10 (2014) 059 | 1407.6013 |
| 42 | CMS Collaboration | Pileup mitigation at CMS in 13 TeV data | JINST 15 (2020) P09018 | CMS-JME-18-001 2003.00503 |
| 43 | CMS Collaboration | Performance of electron reconstruction and selection with the CMS detector in proton-proton collisions at $ \sqrt{s} = $ 8 TeV | JINST 10 (2015) P06005 | CMS-EGM-13-001 1502.02701 |
| 44 | 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 |
| 45 | CMS Collaboration | Performance of CMS muon reconstruction in pp collision events at $ \sqrt{s}= $ 7 TeV | JINST 7 (2012) P10002 | CMS-MUO-10-004 1206.4071 |
| 46 | G. P. Salam | Towards jetography | EPJC 67 (2010) 637 | 0906.1833 |
| 47 | M. Dasgupta, A. Fregoso, S. Marzani, and G. P. Salam | Towards an understanding of jet substructure | JHEP 09 (2013) 029 | 1307.0007 |
| 48 | A. J. Larkoski, S. Marzani, G. Soyez, and J. Thaler | Soft drop | JHEP 05 (2014) 146 | 1402.2657 |
| 49 | C. Brust et al. | Identifying boosted new physics with non-isolated leptons | JHEP 04 (2015) 079 | 1410.0362 |
| 50 | CMS Collaboration | Measurements of differential Z boson production cross sections in proton-proton collisions at $ \sqrt{s} = $ 13 TeV | JHEP 12 (2019) 061 | CMS-SMP-17-010 1909.04133 |
| 51 | J. M. Lindert et al. | Precise predictions for V+jets dark matter backgrounds | EPJC 77 (2017) 829 | 1705.04664 |
| 52 | 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 |
| 53 | CMS Collaboration | CMS luminosity measurement for the 2017 data-taking period at $ \sqrt{s} = $ 13 TeV | CMS-PAS-LUM-17-004 | CMS-PAS-LUM-17-004 |
| 54 | CMS Collaboration | CMS luminosity measurement for the 2018 data-taking period at $ \sqrt{s} = $ 13 TeV | CMS-PAS-LUM-18-002 | CMS-PAS-LUM-18-002 |
| 55 | J. Butterworth et al. | PDF4LHC recommendations for LHC Run II | JPG 43 (2016) 023001 | 1510.03865 |
| 56 | G. Cowan, K. Cranmer, E. Gross, and O. Vitells | Asymptotic formulae for likelihood-based tests of new physics | EPJC 71 (2011) 1554 | 1007.1727 |
| 57 | T. Junk | Confidence level computation for combining searches with small statistics | NIMA 434 (1999) 435 | hep-ex/9902006 |
| 58 | A. L. Read | Presentation of search results: the CLs technique | JPG 28 (2002) 2693 | |
| 59 | E. Gross and O. Vitells | Trial factors for the look elsewhere effect in high energy physics | EPJC 70 (2010) 525 | 1005.1891 |
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