CMS logoCMS event Hgg
Compact Muon Solenoid
LHC, CERN

CMS-B2G-20-013 ; CERN-EP-2021-220
Search for heavy resonances decaying to ZZ or ZW and axion-like particles mediating nonresonant ZZ or ZH production at $\sqrt{s} = $ 13 TeV
JHEP 04 (2022) 087
Abstract: A search has been performed for heavy resonances decaying to ZZ or ZW and for axion-like particles (ALPs) mediating nonresonant ZZ or ZH production, in final states with two charged leptons (${\ell} = $ e, $\mu$) produced by the decay of a Z boson, and two quarks produced by the decay of a Z, W, or Higgs bosonH. The analysis is sensitive to resonances with masses in the range 450 to 1800 GeV. Two categories are defined corresponding to the merged or resolved reconstruction of the hadronically decaying boson. The search is based on data collected during 2016-2018 by the CMS experiment at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. No significant excess is observed in the data above the standard model background expectation. Upper limits on the production cross section of heavy, narrow spin-2 and spin-1 resonances are derived as functions of the resonance mass, and exclusion limits on the production of bulk graviton particles and W' bosons are calculated in the framework of the warped extra dimensions and heavy vector triplet models, respectively. In addition, upper limits on the ALP-mediated diboson production cross section and ALP couplings to standard model particles are obtained in the framework of linear and chiral effective field theories. These are the first limits on nonresonant ALP-mediated ZZ and ZH production obtained by the LHC experiments.
Figures & Tables Summary References CMS Publications
Figures

png pdf
Figure 1:
Feynman diagrams for the processes $\mathrm{g} \mathrm{g} \to {\mathrm{Z} \mathrm{Z}} $ (left) and $\mathrm{g} \mathrm{g} \to {\mathrm{Z} \mathrm{H}} $ (right) via an off-shell ALP ${\mathrm{a}}*$ in the $s$ channel.

png pdf
Figure 1-a:
Feynman diagrams for the processes $\mathrm{g} \mathrm{g} \to {\mathrm{Z} \mathrm{Z}} $ (left) and $\mathrm{g} \mathrm{g} \to {\mathrm{Z} \mathrm{H}} $ (right) via an off-shell ALP ${\mathrm{a}}*$ in the $s$ channel.

png pdf
Figure 1-b:
Feynman diagrams for the processes $\mathrm{g} \mathrm{g} \to {\mathrm{Z} \mathrm{Z}} $ (left) and $\mathrm{g} \mathrm{g} \to {\mathrm{Z} \mathrm{H}} $ (right) via an off-shell ALP ${\mathrm{a}}*$ in the $s$ channel.

png pdf
Figure 2:
Distributions of the merged jet ${\tau _{21}}$ (left) and ${p_{\mathrm {T}}}$ after applying the ${\tau _{21}}$ selection (right) for boosted hadronic V (upper) and H (lower) candidates. The gray band shows the statistical and systematic uncertainties in the background. The background for the ${\tau _{21}}$ distributions is normalized to the number of events in the data; the background normalization for the jet ${p_{\mathrm {T}}}$ distributions is derived from the final fit to the data. The red dashed histograms correspond to a hypothetical linear (chiral) ALP with 1 TeV$^{-1}$ couplings to gluons and ZZ (ZH), and $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The lower panels show the ratio of data to background.

png pdf
Figure 2-a:
Distributions of the merged jet ${\tau _{21}}$ (left) and ${p_{\mathrm {T}}}$ after applying the ${\tau _{21}}$ selection (right) for boosted hadronic V (upper) and H (lower) candidates. The gray band shows the statistical and systematic uncertainties in the background. The background for the ${\tau _{21}}$ distributions is normalized to the number of events in the data; the background normalization for the jet ${p_{\mathrm {T}}}$ distributions is derived from the final fit to the data. The red dashed histograms correspond to a hypothetical linear (chiral) ALP with 1 TeV$^{-1}$ couplings to gluons and ZZ (ZH), and $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The lower panels show the ratio of data to background.

png pdf
Figure 2-b:
Distributions of the merged jet ${\tau _{21}}$ (left) and ${p_{\mathrm {T}}}$ after applying the ${\tau _{21}}$ selection (right) for boosted hadronic V (upper) and H (lower) candidates. The gray band shows the statistical and systematic uncertainties in the background. The background for the ${\tau _{21}}$ distributions is normalized to the number of events in the data; the background normalization for the jet ${p_{\mathrm {T}}}$ distributions is derived from the final fit to the data. The red dashed histograms correspond to a hypothetical linear (chiral) ALP with 1 TeV$^{-1}$ couplings to gluons and ZZ (ZH), and $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The lower panels show the ratio of data to background.

png pdf
Figure 2-c:
Distributions of the merged jet ${\tau _{21}}$ (left) and ${p_{\mathrm {T}}}$ after applying the ${\tau _{21}}$ selection (right) for boosted hadronic V (upper) and H (lower) candidates. The gray band shows the statistical and systematic uncertainties in the background. The background for the ${\tau _{21}}$ distributions is normalized to the number of events in the data; the background normalization for the jet ${p_{\mathrm {T}}}$ distributions is derived from the final fit to the data. The red dashed histograms correspond to a hypothetical linear (chiral) ALP with 1 TeV$^{-1}$ couplings to gluons and ZZ (ZH), and $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The lower panels show the ratio of data to background.

png pdf
Figure 2-d:
Distributions of the merged jet ${\tau _{21}}$ (left) and ${p_{\mathrm {T}}}$ after applying the ${\tau _{21}}$ selection (right) for boosted hadronic V (upper) and H (lower) candidates. The gray band shows the statistical and systematic uncertainties in the background. The background for the ${\tau _{21}}$ distributions is normalized to the number of events in the data; the background normalization for the jet ${p_{\mathrm {T}}}$ distributions is derived from the final fit to the data. The red dashed histograms correspond to a hypothetical linear (chiral) ALP with 1 TeV$^{-1}$ couplings to gluons and ZZ (ZH), and $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The lower panels show the ratio of data to background.

png pdf
Figure 3:
Distributions of the untagged and loose and medium DeepCSV tags for the more b-like subjet (left) and the less b-like subjet (right) of the boosted hadronic H candidates in SR2. The gray band shows the statistical and systematic uncertainties in the background. Background normalizations are derived from the final fit to the data. The red dashed histograms correspond to a hypothetical chiral ALP with 1 TeV$^{-1}$ couplings to gluons and ZH, and $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The lower panels show the ratio of data to background.

png pdf
Figure 3-a:
Distributions of the untagged and loose and medium DeepCSV tags for the more b-like subjet (left) and the less b-like subjet (right) of the boosted hadronic H candidates in SR2. The gray band shows the statistical and systematic uncertainties in the background. Background normalizations are derived from the final fit to the data. The red dashed histograms correspond to a hypothetical chiral ALP with 1 TeV$^{-1}$ couplings to gluons and ZH, and $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The lower panels show the ratio of data to background.

png pdf
Figure 3-b:
Distributions of the untagged and loose and medium DeepCSV tags for the more b-like subjet (left) and the less b-like subjet (right) of the boosted hadronic H candidates in SR2. The gray band shows the statistical and systematic uncertainties in the background. Background normalizations are derived from the final fit to the data. The red dashed histograms correspond to a hypothetical chiral ALP with 1 TeV$^{-1}$ couplings to gluons and ZH, and $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The lower panels show the ratio of data to background.

png pdf
Figure 4:
Distributions of the merged jet ${m_\mathrm {J}}$ (upper) and the dijet ${m_\mathrm {jj}}$ (lower) for the untagged (left) and tagged (right) categories. The distributions include events in the signal regions SR1 and SR2 and in the sideband SB; the corresponding boundaries have been defined in the text. The gray band shows the statistical and systematic uncertainties in the background. Background normalizations are derived from the final fit to the data. The red dashed histograms correspond to a hypothetical linear ALP with 1 TeV$^{-1}$ couplings to gluons and ZZ, and $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The lower panels show the ratio of data to background.

png pdf
Figure 4-a:
Distributions of the merged jet ${m_\mathrm {J}}$ (upper) and the dijet ${m_\mathrm {jj}}$ (lower) for the untagged (left) and tagged (right) categories. The distributions include events in the signal regions SR1 and SR2 and in the sideband SB; the corresponding boundaries have been defined in the text. The gray band shows the statistical and systematic uncertainties in the background. Background normalizations are derived from the final fit to the data. The red dashed histograms correspond to a hypothetical linear ALP with 1 TeV$^{-1}$ couplings to gluons and ZZ, and $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The lower panels show the ratio of data to background.

png pdf
Figure 4-b:
Distributions of the merged jet ${m_\mathrm {J}}$ (upper) and the dijet ${m_\mathrm {jj}}$ (lower) for the untagged (left) and tagged (right) categories. The distributions include events in the signal regions SR1 and SR2 and in the sideband SB; the corresponding boundaries have been defined in the text. The gray band shows the statistical and systematic uncertainties in the background. Background normalizations are derived from the final fit to the data. The red dashed histograms correspond to a hypothetical linear ALP with 1 TeV$^{-1}$ couplings to gluons and ZZ, and $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The lower panels show the ratio of data to background.

png pdf
Figure 4-c:
Distributions of the merged jet ${m_\mathrm {J}}$ (upper) and the dijet ${m_\mathrm {jj}}$ (lower) for the untagged (left) and tagged (right) categories. The distributions include events in the signal regions SR1 and SR2 and in the sideband SB; the corresponding boundaries have been defined in the text. The gray band shows the statistical and systematic uncertainties in the background. Background normalizations are derived from the final fit to the data. The red dashed histograms correspond to a hypothetical linear ALP with 1 TeV$^{-1}$ couplings to gluons and ZZ, and $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The lower panels show the ratio of data to background.

png pdf
Figure 4-d:
Distributions of the merged jet ${m_\mathrm {J}}$ (upper) and the dijet ${m_\mathrm {jj}}$ (lower) for the untagged (left) and tagged (right) categories. The distributions include events in the signal regions SR1 and SR2 and in the sideband SB; the corresponding boundaries have been defined in the text. The gray band shows the statistical and systematic uncertainties in the background. Background normalizations are derived from the final fit to the data. The red dashed histograms correspond to a hypothetical linear ALP with 1 TeV$^{-1}$ couplings to gluons and ZZ, and $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The lower panels show the ratio of data to background.

png pdf
Figure 5:
The sideband diboson mass distributions for the boosted V (upper), resolved V (lower), untagged (left), and tagged (right) categories after fitting the sideband data alone. The points show the data, while the filled histograms show the background contributions. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panel shows the ratio of data to background.

png pdf
Figure 5-a:
The sideband diboson mass distributions for the boosted V (upper), resolved V (lower), untagged (left), and tagged (right) categories after fitting the sideband data alone. The points show the data, while the filled histograms show the background contributions. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panel shows the ratio of data to background.

png pdf
Figure 5-b:
The sideband diboson mass distributions for the boosted V (upper), resolved V (lower), untagged (left), and tagged (right) categories after fitting the sideband data alone. The points show the data, while the filled histograms show the background contributions. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panel shows the ratio of data to background.

png pdf
Figure 5-c:
The sideband diboson mass distributions for the boosted V (upper), resolved V (lower), untagged (left), and tagged (right) categories after fitting the sideband data alone. The points show the data, while the filled histograms show the background contributions. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panel shows the ratio of data to background.

png pdf
Figure 5-d:
The sideband diboson mass distributions for the boosted V (upper), resolved V (lower), untagged (left), and tagged (right) categories after fitting the sideband data alone. The points show the data, while the filled histograms show the background contributions. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panel shows the ratio of data to background.

png pdf
Figure 6:
The SR1 ${m_{{\mathrm{Z} \mathrm{V}}}}$ distributions for the boosted V (upper), resolved V (lower), untagged (left), and tagged (right) categories after fitting the signal and sideband regions with a model comprising signal (ALP linear ZZ) plus background. The last bin includes events with ${m_{{\mathrm{Z} \mathrm{V}}}}$ values up to 3000 GeV. The points show the data, while the filled histograms show the background contributions. The signal is represented by the red dashed histogram, normalized to the observed 95% confidence level cross section limit at $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panels show the ratio of data to background.

png pdf
Figure 6-a:
The SR1 ${m_{{\mathrm{Z} \mathrm{V}}}}$ distributions for the boosted V (upper), resolved V (lower), untagged (left), and tagged (right) categories after fitting the signal and sideband regions with a model comprising signal (ALP linear ZZ) plus background. The last bin includes events with ${m_{{\mathrm{Z} \mathrm{V}}}}$ values up to 3000 GeV. The points show the data, while the filled histograms show the background contributions. The signal is represented by the red dashed histogram, normalized to the observed 95% confidence level cross section limit at $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panels show the ratio of data to background.

png pdf
Figure 6-b:
The SR1 ${m_{{\mathrm{Z} \mathrm{V}}}}$ distributions for the boosted V (upper), resolved V (lower), untagged (left), and tagged (right) categories after fitting the signal and sideband regions with a model comprising signal (ALP linear ZZ) plus background. The last bin includes events with ${m_{{\mathrm{Z} \mathrm{V}}}}$ values up to 3000 GeV. The points show the data, while the filled histograms show the background contributions. The signal is represented by the red dashed histogram, normalized to the observed 95% confidence level cross section limit at $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panels show the ratio of data to background.

png pdf
Figure 6-c:
The SR1 ${m_{{\mathrm{Z} \mathrm{V}}}}$ distributions for the boosted V (upper), resolved V (lower), untagged (left), and tagged (right) categories after fitting the signal and sideband regions with a model comprising signal (ALP linear ZZ) plus background. The last bin includes events with ${m_{{\mathrm{Z} \mathrm{V}}}}$ values up to 3000 GeV. The points show the data, while the filled histograms show the background contributions. The signal is represented by the red dashed histogram, normalized to the observed 95% confidence level cross section limit at $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panels show the ratio of data to background.

png pdf
Figure 6-d:
The SR1 ${m_{{\mathrm{Z} \mathrm{V}}}}$ distributions for the boosted V (upper), resolved V (lower), untagged (left), and tagged (right) categories after fitting the signal and sideband regions with a model comprising signal (ALP linear ZZ) plus background. The last bin includes events with ${m_{{\mathrm{Z} \mathrm{V}}}}$ values up to 3000 GeV. The points show the data, while the filled histograms show the background contributions. The signal is represented by the red dashed histogram, normalized to the observed 95% confidence level cross section limit at $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panels show the ratio of data to background.

png pdf
Figure 7:
The SR2 ${m_{{\mathrm{Z} \mathrm{H}}}}$ distributions for the boosted H (upper), resolved H (lower), untagged (left), and tagged (right) categories after fitting the signal and sideband regions with a model comprising signal (ALP chiral ZH) plus background. The last bin includes events with ${m_{{\mathrm{Z} \mathrm{H}}}}$ values up to 3000 GeV. The points show the data, while the filled histograms show the background contributions. The signal is represented by the red dashed histogram, normalized to the observed 95% confidence level cross section limit at $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panels show the ratio of data to background.

png pdf
Figure 7-a:
The SR2 ${m_{{\mathrm{Z} \mathrm{H}}}}$ distributions for the boosted H (upper), resolved H (lower), untagged (left), and tagged (right) categories after fitting the signal and sideband regions with a model comprising signal (ALP chiral ZH) plus background. The last bin includes events with ${m_{{\mathrm{Z} \mathrm{H}}}}$ values up to 3000 GeV. The points show the data, while the filled histograms show the background contributions. The signal is represented by the red dashed histogram, normalized to the observed 95% confidence level cross section limit at $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panels show the ratio of data to background.

png pdf
Figure 7-b:
The SR2 ${m_{{\mathrm{Z} \mathrm{H}}}}$ distributions for the boosted H (upper), resolved H (lower), untagged (left), and tagged (right) categories after fitting the signal and sideband regions with a model comprising signal (ALP chiral ZH) plus background. The last bin includes events with ${m_{{\mathrm{Z} \mathrm{H}}}}$ values up to 3000 GeV. The points show the data, while the filled histograms show the background contributions. The signal is represented by the red dashed histogram, normalized to the observed 95% confidence level cross section limit at $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panels show the ratio of data to background.

png pdf
Figure 7-c:
The SR2 ${m_{{\mathrm{Z} \mathrm{H}}}}$ distributions for the boosted H (upper), resolved H (lower), untagged (left), and tagged (right) categories after fitting the signal and sideband regions with a model comprising signal (ALP chiral ZH) plus background. The last bin includes events with ${m_{{\mathrm{Z} \mathrm{H}}}}$ values up to 3000 GeV. The points show the data, while the filled histograms show the background contributions. The signal is represented by the red dashed histogram, normalized to the observed 95% confidence level cross section limit at $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panels show the ratio of data to background.

png pdf
Figure 7-d:
The SR2 ${m_{{\mathrm{Z} \mathrm{H}}}}$ distributions for the boosted H (upper), resolved H (lower), untagged (left), and tagged (right) categories after fitting the signal and sideband regions with a model comprising signal (ALP chiral ZH) plus background. The last bin includes events with ${m_{{\mathrm{Z} \mathrm{H}}}}$ values up to 3000 GeV. The points show the data, while the filled histograms show the background contributions. The signal is represented by the red dashed histogram, normalized to the observed 95% confidence level cross section limit at $ {f_{\mathrm{a}}} = $ 3 TeV; the cross sections have been multiplied by the factors indicated in the legends for better visibility. The gray band indicates the statistical and post-fit systematic uncertainties in the normalization and shape of the background. The lower panels show the ratio of data to background.

png pdf
Figure 8:
Observed and expected 95% CL upper limits on $\sigma _{\mathrm{G}} \, + \, {\mathcal {B}} (\mathrm{G} \to {\mathrm{Z} \mathrm{Z}})$ (left) and $\sigma _{\mathrm{W'}} \, + \, {\mathcal {B}} (\mathrm{W'} \to {\mathrm{Z} \mathrm{W}})$ (right) as a function of the resonance mass, taking into account all statistical and systematic uncertainties. The electron and muon channels and the various categories used in the analysis are combined together. The green (inner) and yellow (outer) bands represent the 68 and 95% coverage of the expected limit in the background-only hypothesis. Theoretical predictions for the signal production cross section are also shown: (left) ${\mathrm{G}}$ produced in the WED bulk graviton model with $ {\tilde{\kappa}} =$ 0.5; (right) W' produced in the framework of HVT model A and B with $g_{\mathrm{V}}=$ 1 and 3, respectively.

png pdf
Figure 8-a:
Observed and expected 95% CL upper limits on $\sigma _{\mathrm{G}} \, + \, {\mathcal {B}} (\mathrm{G} \to {\mathrm{Z} \mathrm{Z}})$ (left) and $\sigma _{\mathrm{W'}} \, + \, {\mathcal {B}} (\mathrm{W'} \to {\mathrm{Z} \mathrm{W}})$ (right) as a function of the resonance mass, taking into account all statistical and systematic uncertainties. The electron and muon channels and the various categories used in the analysis are combined together. The green (inner) and yellow (outer) bands represent the 68 and 95% coverage of the expected limit in the background-only hypothesis. Theoretical predictions for the signal production cross section are also shown: (left) ${\mathrm{G}}$ produced in the WED bulk graviton model with $ {\tilde{\kappa}} =$ 0.5; (right) W' produced in the framework of HVT model A and B with $g_{\mathrm{V}}=$ 1 and 3, respectively.

png pdf
Figure 8-b:
Observed and expected 95% CL upper limits on $\sigma _{\mathrm{G}} \, + \, {\mathcal {B}} (\mathrm{G} \to {\mathrm{Z} \mathrm{Z}})$ (left) and $\sigma _{\mathrm{W'}} \, + \, {\mathcal {B}} (\mathrm{W'} \to {\mathrm{Z} \mathrm{W}})$ (right) as a function of the resonance mass, taking into account all statistical and systematic uncertainties. The electron and muon channels and the various categories used in the analysis are combined together. The green (inner) and yellow (outer) bands represent the 68 and 95% coverage of the expected limit in the background-only hypothesis. Theoretical predictions for the signal production cross section are also shown: (left) ${\mathrm{G}}$ produced in the WED bulk graviton model with $ {\tilde{\kappa}} =$ 0.5; (right) W' produced in the framework of HVT model A and B with $g_{\mathrm{V}}=$ 1 and 3, respectively.

png pdf
Figure 9:
Observed and expected 95% CL upper limits on the ALP linear $ | c_{\tilde{\mathrm{G}}} c_{\tilde{\mathrm{Z}}} | $ (left) and the ALP chiral $ | c_{\tilde{\mathrm{G}}} \tilde{a}_{\text {2D}} | $ (right) coupling coefficients as a function of the mass scale ${f_{\mathrm{a}}}$ for ALP masses $m_{\mathrm{a}} < $ 100 GeV.

png pdf
Figure 9-a:
Observed and expected 95% CL upper limits on the ALP linear $ | c_{\tilde{\mathrm{G}}} c_{\tilde{\mathrm{Z}}} | $ (left) and the ALP chiral $ | c_{\tilde{\mathrm{G}}} \tilde{a}_{\text {2D}} | $ (right) coupling coefficients as a function of the mass scale ${f_{\mathrm{a}}}$ for ALP masses $m_{\mathrm{a}} < $ 100 GeV.

png pdf
Figure 9-b:
Observed and expected 95% CL upper limits on the ALP linear $ | c_{\tilde{\mathrm{G}}} c_{\tilde{\mathrm{Z}}} | $ (left) and the ALP chiral $ | c_{\tilde{\mathrm{G}}} \tilde{a}_{\text {2D}} | $ (right) coupling coefficients as a function of the mass scale ${f_{\mathrm{a}}}$ for ALP masses $m_{\mathrm{a}} < $ 100 GeV.
Tables

png pdf
Table 1:
Summary of selection requirements and categorization.

png pdf
Table 2:
Summary of systematic uncertainties, quoted in percent, affecting the normalization of background and signal samples. Where a systematic uncertainty depends on the signa ZV or ZH channel or mass, the smallest and largest values are reported. In the case of a systematic uncertainty applying only to a specific background source, the source is indicated in parentheses. Systematic uncertainties too small to be considered are written as "$ < $0.1'', while a dash (--) represents uncertainties not applicable in the specific analysis category.

png pdf
Table 3:
Selection efficiencies in percent for the bulk graviton, W', and ALP linear and chiral models.

png pdf
Table 4:
Expected and observed 95% CL upper limits on $\sigma (\mathrm{g} \mathrm{g} \to {\mathrm{a}}* \to {\mathrm{Z} \mathrm{Z}} / {\mathrm{Z} \mathrm{H}})$ in fb for $ {f_{\mathrm{a}}} = $ 3 TeV. The $ \pm $1$ \sigma $ and $ \pm $2$ \sigma $ numbers represent the 68 and 95% coverage of the expected limit for the background-only hypothesis.
Summary
A search has been presented for heavy resonances decaying to ZZ or ZW, and nonresonant ZZ or ZH production (where H is the Higgs boson) mediated by axion-like particles (ALPs). The analysis is sensitive to resonances with masses in the range from 450 to 1800 GeV. Two categories are defined based on the merged or resolved reconstruction of the hadronically decaying boson. The search is based on data collected in 2016-2018 by the CMS experiment at the LHC in proton-proton collisions with a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$.

No significant excess is observed in the data above the standard model expectations. Depending on the resonance mass, upper limits of 2-90 and 5-120 fb have been set on the product of the cross section of a spin-2 bulk graviton and the ZZ branching fraction, and on a spin-1 W' signal and the ZW branching fraction, respectively. Upper limits on the nonresonant ALP-mediated ZZ and ZH production cross sections for a new physics energy scale ${f_{\mathrm{a}}} = $ 3 TeV and ALP masses $m_{\mathrm{a}} < $ 100 GeV have been established at 162 and 57 fb, respectively. Depending on the value of the scale ${f_{\mathrm{a}}}$, upper limits on the product of the ALP coupling to gluons with the relevant coupling to ZZ or ZH of 0.02-0.09 TeV$^{-2}$ have been set, valid for ALP masses $m_{\mathrm{a}} < $ 100 GeV. These are the first limits based on nonresonant ALP-mediated ZZ and ZH production obtained by the LHC experiments.
References
1 K. Agashe, H. Davoudiasl, G. Perez, and A. Soni Warped gravitons at the LHC and beyond PRD 76 (2007) 036006 hep-ph/0701186
2 L. Randall and R. Sundrum A large mass hierarchy from a small extra dimension PRL 83 (1999) 3370 hep-ph/9905221
3 L. Randall and R. Sundrum An alternative to compactification PRL 83 (1999) 4690 hep-th/9906064
4 D. Pappadopulo, A. Thamm, R. Torre, and A. Wulzer Heavy vector triplets: Bridging theory and data JHEP 09 (2014) 060 1402.4431
5 H. Georgi, D. B. Kaplan, and L. Randall Manifesting the invisible axion at low energies PLB 169 (1986) 73
6 K. Choi, K. Kang, and J. E. Kim Effects of $ \eta^\prime $ in low-energy axion physics PLB 181 (1986) 145
7 I. Brivio et al. ALPs effective field theory and collider signatures EPJC 77 (2017) 572 1701.05379
8 M. Bauer, M. Neubert, and A. Thamm Collider probes of axion-like particles JHEP 12 (2017) 044 1708.00443
9 M. B. Gavela, J. M. No, V. Sanz, and J. F. de Troc\'oniz Nonresonant searches for axionlike particles at the LHC PRL 124 (2020) 051802 1905.12953
10 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
11 CMS Collaboration Search for a heavy resonance decaying into a Z boson and a vector boson in the $ \nu \overline{\nu}\mathrm{q}\overline{\mathrm{q}} $ final state JHEP 07 (2018) 075 CMS-B2G-17-005
1803.03838
12 CMS Collaboration Search for a heavy resonance decaying into a Z boson and a Z or W boson in 2$ \ell2q $ final states at $ \sqrt{s}= $ 13 TeV JHEP 09 (2018) 101 CMS-B2G-17-013
1803.10093
13 CMS Collaboration Combination of CMS searches for heavy resonances decaying to pairs of bosons or leptons PLB 798 (2019) 134952 CMS-B2G-18-006
1906.00057
14 ATLAS Collaboration Search for heavy diboson resonances in semileptonic final states in $ pp $ collisions at $ \sqrt{s}= $ 13 TeV with the ATLAS detector EPJC 80 (2020) 1165 2004.14636
15 CMS Collaboration Search for a heavy vector resonance decaying to a Z boson and a Higgs boson in proton-proton collisions at $ \sqrt{s} = $ 13 TeV EPJC 81 (2021) 688 CMS-B2G-19-006
2102.08198
16 S. Carra et al. Constraining off-shell production of axion-like particles with $ Z\gamma $ and $ WW $ differential cross-section measurements 2021 2106.10085
17 CMS Collaboration HEPData record for this analysis link
18 A. L. Fitzpatrick, J. Kaplan, L. Randall, and L.-T. Wang Searching for the Kaluza-Klein graviton in bulk RS models JHEP 09 (2007) 013 hep-ph/0701150
19 W. D. Goldberger and M. B. Wise Modulus stabilization with bulk fields PRL 83 (1999) 4922 hep-ph/9907447
20 A. Carvalho Gravity particles from warped extra dimensions, predictions for LHC 2014 1404.0102
21 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
22 W. Buchmuller and D. Wyler Effective Lagrangian analysis of new interactions and flavor conservation NPB 268 (1986) 621
23 B. Grzadkowski, M. Iskrzynski, M. Misiak, and J. Rosiek Dimension-six terms in the standard model Lagrangian JHEP 10 (2010) 085 1008.4884
24 F. Feruglio The chiral approach to the electroweak interactions Int. J. Mod. Phys. A 8 (1993) 4937 hep-ph/9301281
25 A. Azatov, R. Contino, and J. Galloway Model-independent bounds on a light Higgs JHEP 04 (2012) 127 1202.3415
26 R. Alonso et al. The effective chiral Lagrangian for a light dynamical Higgs particle PLB 722 (2013) 330 1212.3305
27 G. Buchalla, O. Cat\`a, and C. Krause Complete electroweak chiral Lagrangian with a light Higgs at NLO NPB 880 (2014) 552 1307.5017
28 J. M. Lindert et al. Precise predictions for $ {V}+ $ jets dark matter backgrounds EPJC 77 (2017) 829 1705.04664
29 T. Sjostrand 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 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
36 CMS Collaboration The CMS trigger system JINST 12 (2017) P01020 CMS-TRG-12-001
1609.02366
37 CMS Collaboration The CMS experiment at the CERN LHC JINST 3 (2008) S08004 CMS-00-001
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 M. Cacciari, G. P. Salam, and G. Soyez The anti-$ {k_{\mathrm{T}}} $ jet clustering algorithm JHEP 04 (2008) 063 0802.1189
40 M. Cacciari, G. P. Salam, and G. Soyez FastJet user manual EPJC 72 (2012) 1896 1111.6097
41 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
42 CMS Tracker Group Collaboration The CMS phase-1 pixel detector upgrade JINST 16 (2021) P02027 2012.14304
43 CMS Collaboration Track impact parameter resolution for the full pseudo rapidity coverage in the 2017 dataset with the CMS phase-1 pixel detector CDS
44 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
45 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
46 CMS Collaboration Pileup mitigation at CMS in 13 TeV data JINST 15 (2020) P09018 CMS-JME-18-001
2003.00503
47 D. Bertolini, P. Harris, M. Low, and N. Tran Pileup per particle identification JHEP 10 (2014) 059 1407.6013
48 CMS Collaboration Jet algorithms performance in 13 TeV data CMS-PAS-JME-16-003 CMS-PAS-JME-16-003
49 M. Dasgupta, A. Fregoso, S. Marzani, and G. P. Salam Towards an understanding of jet substructure JHEP 09 (2013) 029 1307.0007
50 A. J. Larkoski, S. Marzani, G. Soyez, and J. Thaler Soft drop JHEP 05 (2014) 146 1402.2657
51 J. Thaler and K. Van Tilburg Identifying boosted objects with N-subjettiness JHEP 03 (2011) 015 1011.2268
52 CMS Collaboration Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV JINST 13 (2018) P05011 CMS-BTV-16-002
1712.07158
53 CMS Collaboration Measurement of the inclusive $ W $ and $ Z $ production cross sections in $ pp $ collisions at $ \sqrt{s}= $ 7 TeV JHEP 10 (2011) 132 CMS-EWK-10-005
1107.4789
54 CMS Collaboration Identification techniques for highly boosted W bosons that decay into hadrons JHEP 12 (2014) 017 CMS-JME-13-006
1410.4227
55 J. Butterworth et al. PDF4LHC recommendations for LHC Run II JPG 43 (2016) 023001 1510.03865
56 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
57 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
58 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
59 A. L. Read Presentation of search results: The CL$ _{\text{s}} $ technique JPG 28 (2002) 2693
60 T. Junk Confidence level computation for combining searches with small statistics NIMA 434 (1999) 435 hep-ex/9902006
61 G. Cowan, K. Cranmer, E. Gross, and O. Vitells Asymptotic formulae for likelihood-based tests of new physics EPJC 71 (2011) 1554 1007.1727
62 ATLAS Collaboration, CMS Collaboration, LHC Higgs Combination Group Procedure for the LHC Higgs boson search combination in Summer 2011 CMS-NOTE-2011-005
63 ATLAS and CMS Collaborations Measurements of the Higgs boson production and decay rates and constraints on its couplings from a combined ATLAS and CMS analysis of the LHC pp collision data at $ \sqrt{s}= $ 7 and 8 TeV JHEP 08 (2016) 045 1606.02266
Compact Muon Solenoid
LHC, CERN