Compact Muon Solenoid
LHC, CERN
Visit us: CMS Public Website, CMS Physics ;
Contact us: CMS Publications Committee
| CMS-PAS-HIG-19-007 | ||
| Search for a low-mass dilepton resonance in Higgs boson decays to four-lepton final states at $\sqrt{s}= $ 13 TeV | ||
| CMS Collaboration | ||
| May 2020 | ||
| Abstract: A generic search for a low mass dilepton resonance in Higgs boson decays is conducted in the four-lepton final state. The decay is assumed to proceed via two new particles (beyond the standard model), or one new particle in association with a Z boson. The search uses proton-proton collision data collected by the CMS detector, corresponding to an integrated luminosity of 137 fb$^{-1}$, at a center-of-mass energy $\sqrt{s}= $ 13 TeV. No significant deviation from the standard model expectation is observed. Upper limits at 95% confidence level are set on model-independent cross sections and Higgs boson decay branching fractions. Additionally, limits on dark photon and axion-like particle models are reported. | ||
|
Links:
CDS record (PDF) ;
inSPIRE record ;
CADI line (restricted) ;
These preliminary results are superseded in this paper, Submitted to EPJC. The superseded preliminary plots can be found here. |
||
| Figures | |
png pdf |
Figure 1:
Feynman diagrams for Higgs boson decay via the kinematic mixing (left) or Higgs mixing mechanism (right) [3]. |
png pdf |
Figure 2:
Event yields in $m_\mathrm {Z_2}$ with the ${\mathrm{Z} \mathrm{X}}$ selection for the muon and electron channel. Numbers in the legend show the total event yields with the ${\mathrm{Z} \mathrm{X}}$ selection corresponding to data, each background and signal process. |
png pdf |
Figure 2-a:
Event yields in $m_\mathrm {Z_2}$ with the ${\mathrm{Z} \mathrm{X}}$ selection for the muon channel. Numbers in the legend show the total event yields with the ${\mathrm{Z} \mathrm{X}}$ selection corresponding to data, each background and signal process. |
png pdf |
Figure 2-b:
Event yields in $m_\mathrm {Z_2}$ with the ${\mathrm{Z} \mathrm{X}}$ selection for the electron channel. Numbers in the legend show the total event yields with the ${\mathrm{Z} \mathrm{X}}$ selection corresponding to data, each background and signal process. |
png pdf |
Figure 3:
Event yields in $({m_{\mathrm {{\mathrm{Z} _{\mathrm {1}}}}}} + {m_{\mathrm {{\mathrm{Z} _{\mathrm {2}}}}}})/2$ with the ${\mathrm{X} \mathrm{X}}$ selection for the 4$\mu$, 2e2$\mu$, 4e final states. Numbers in the legend show the total event yields with the ${\mathrm{Z} \mathrm{X}}$ selection corresponding to data, each background and signal process. |
png pdf |
Figure 3-a:
Event yields in $({m_{\mathrm {{\mathrm{Z} _{\mathrm {1}}}}}} + {m_{\mathrm {{\mathrm{Z} _{\mathrm {2}}}}}})/2$ with the ${\mathrm{X} \mathrm{X}}$ selection for the 4$\mu$ final state. Numbers in the legend show the total event yields with the ${\mathrm{Z} \mathrm{X}}$ selection corresponding to data, each background and signal process. |
png pdf |
Figure 3-b:
Event yields in $({m_{\mathrm {{\mathrm{Z} _{\mathrm {1}}}}}} + {m_{\mathrm {{\mathrm{Z} _{\mathrm {2}}}}}})/2$ with the ${\mathrm{X} \mathrm{X}}$ selection for the 2e2$\mu$ final state. Numbers in the legend show the total event yields with the ${\mathrm{Z} \mathrm{X}}$ selection corresponding to data, each background and signal process. |
png pdf |
Figure 3-c:
Event yields in $({m_{\mathrm {{\mathrm{Z} _{\mathrm {1}}}}}} + {m_{\mathrm {{\mathrm{Z} _{\mathrm {2}}}}}})/2$ with the ${\mathrm{X} \mathrm{X}}$ selection for the 4e final state. Numbers in the legend show the total event yields with the ${\mathrm{Z} \mathrm{X}}$ selection corresponding to data, each background and signal process. |
png pdf |
Figure 4:
Expected and observed 95% CL limit on ${\cal B}(\mathrm{H} \to \mathrm{Z} \mathrm{X}) \times {\cal B}(\mathrm{X} \to \mathrm{e} \mathrm{e}$ or $ \mu \mu)$ assuming a democratic decay of X to dielectrons and dimuons, ${\cal B}(\mathrm{H} \to \mathrm{Z} \mathrm{X}) \times {\cal B}(\mathrm{X} \to \mu \mu)$ assuming X decays to dimuons only, and ${\cal B}(\mathrm{H} \to \mathrm{Z} \mathrm{X}) \times {\cal B}(\mathrm{X} \to \mathrm{e} \mathrm{e})$ assuming X decays to dielectrons only. The dashed black curve is the expected upper limit, with one and two standard-deviation bands shown in green and yellow, respectively. The solid black curve is the observed upper limit. The discontinuity at 12 GeV in uncertainty for the theory prediction (red curve) is due to the switch from experimentally-driven to theory-driven uncertainty estimates of ${\cal B}({\mathrm{Z} _{\mathrm {D}}} \to \mathrm{e} \mathrm{e}$ or $\mu \mu)$, as described in text [3]. |
png pdf |
Figure 4-a:
Expected and observed 95% CL limit on ${\cal B}(\mathrm{H} \to \mathrm{Z} \mathrm{X}) \times {\cal B}(\mathrm{X} \to \mathrm{e} \mathrm{e}$ or $ \mu \mu)$ assuming a democratic decay of X to dielectrons and dimuons. The dashed black curve is the expected upper limit, with one and two standard-deviation bands shown in green and yellow, respectively. The solid black curve is the observed upper limit. The discontinuity at 12 GeV in uncertainty for the theory prediction (red curve) is due to the switch from experimentally-driven to theory-driven uncertainty estimates of ${\cal B}({\mathrm{Z} _{\mathrm {D}}} \to \mathrm{e} \mathrm{e}$ or $\mu \mu)$, as described in text [3]. |
png pdf |
Figure 4-b:
Expected and observed 95% CL limit on ${\cal B}(\mathrm{H} \to \mathrm{Z} \mathrm{X}) \times {\cal B}(\mathrm{X} \to \mu \mu)$ assuming X decays to dimuons only. The dashed black curve is the expected upper limit, with one and two standard-deviation bands shown in green and yellow, respectively. The solid black curve is the observed upper limit. |
png pdf |
Figure 4-c:
Expected and observed 95% CL limit on ${\cal B}(\mathrm{H} \to \mathrm{Z} \mathrm{X}) \times {\cal B}(\mathrm{X} \to \mathrm{e} \mathrm{e})$ assuming X decays to dielectrons only. The dashed black curve is the expected upper limit, with one and two standard-deviation bands shown in green and yellow, respectively. The solid black curve is the observed upper limit. |
png pdf |
Figure 5:
Expected and observed 95% CL limit on ${\cal B}(\mathrm{H} \to \mathrm{X} \mathrm{X}) \times {\cal B}(\mathrm{X} \to \mathrm{e} \mathrm{e}$ or $\mu \mu)^2$ assuming a democratic decay of X to dielectron and dimuons, ${\cal B}(\mathrm{H} \to \mathrm{X} \mathrm{X}) \times {\cal B}(\mathrm{X} \to \mu \mu)^2$ assuming X decays to dimuons only, and ${\cal B}(\mathrm{H} \to \mathrm{X} \mathrm{X}) \times {\cal B}(\mathrm{X} \to \mathrm{e} \mathrm{e})^2$ assuming X decays to dielectrons only. The dashed black curve is the expected upper limit, with one and two standard-deviation bands shown in green and yellow, respectively. The solid black curve is the observed upper limit. The discontinuity at 12 GeV in uncertainty for the theory prediction (red curve) is due to the switch from experimentally-driven to theory-driven uncertainty estimates of ${\cal B}({\mathrm{Z} _{\mathrm {D}}} \to \mathrm{e} \mathrm{e}$ or $\mu \mu)$, as described in text [3]. |
png pdf |
Figure 5-a:
Expected and observed 95% CL limit on ${\cal B}(\mathrm{H} \to \mathrm{X} \mathrm{X}) \times {\cal B}(\mathrm{X} \to \mathrm{e} \mathrm{e}$ or $\mu \mu)^2$ assuming a democratic decay of X to dielectron and dimuons. The dashed black curve is the expected upper limit, with one and two standard-deviation bands shown in green and yellow, respectively. The solid black curve is the observed upper limit. The discontinuity at 12 GeV in uncertainty for the theory prediction (red curve) is due to the switch from experimentally-driven to theory-driven uncertainty estimates of ${\cal B}({\mathrm{Z} _{\mathrm {D}}} \to \mathrm{e} \mathrm{e}$ or $\mu \mu)$, as described in text [3]. |
png pdf |
Figure 5-b:
Expected and observed 95% CL limit on ${\cal B}(\mathrm{H} \to \mathrm{X} \mathrm{X}) \times {\cal B}(\mathrm{X} \to \mu \mu)^2$ assuming X decays to dimuons only. The dashed black curve is the expected upper limit, with one and two standard-deviation bands shown in green and yellow, respectively. The solid black curve is the observed upper limit. |
png pdf |
Figure 5-c:
Expected and observed 95% CL limit on ${\cal B}(\mathrm{H} \to \mathrm{X} \mathrm{X}) \times {\cal B}(\mathrm{X} \to \mathrm{e} \mathrm{e})^2$ assuming X decays to dielectrons only. The dashed black curve is the expected upper limit, with one and two standard-deviation bands shown in green and yellow, respectively. The solid black curve is the observed upper limit. |
png pdf |
Figure 6:
Expected and observed 95% CL limits on $\kappa $, based on the ${\mathrm{X} \mathrm{X}}$ selection, as function of ${m_{\mathrm {{\mathrm{Z} _{\mathrm {D}}}}}}$. The dashed black curve is the expected upper limit, with one and two standard-deviation bands shown in green and yellow, respectively. The solid black curve is the observed upper limit. |
png pdf |
Figure 7:
Exclusion limit on ${C^{\mathrm {eff}}_{\mathrm {ZH}}/{\Lambda} }$ (left) and ${C^{\mathrm {eff}}_{\mathrm {aH}}/{\Lambda ^2}}$ (right) assuming democratic decays of the ALP to dimuons and dielectrons as function of $m_\text {a}$ at 95% CL. Expected and observed 95% CL limit on ${C^{\mathrm {eff}}_{\mathrm {ZH}}/{\Lambda}}$ and ${C^{\mathrm {eff}}_{\mathrm {aH}}/{\Lambda ^2}}$ as function of $m_{\mathrm{a}}$. The dashed black curve is the expected upper limit, with one and two standard-deviation bands shown in green and yellow, respectively. The solid black curve is the observed upper limit. |
png pdf |
Figure 7-a:
Exclusion limit on ${C^{\mathrm {eff}}_{\mathrm {ZH}}/{\Lambda} }$ assuming democratic decays of the ALP to dimuons and dielectrons as function of $m_\text {a}$ at 95% CL. Expected and observed 95% CL limit on ${C^{\mathrm {eff}}_{\mathrm {ZH}}/{\Lambda}}$ and ${C^{\mathrm {eff}}_{\mathrm {aH}}/{\Lambda ^2}}$ as function of $m_{\mathrm{a}}$. The dashed black curve is the expected upper limit, with one and two standard-deviation bands shown in green and yellow, respectively. The solid black curve is the observed upper limit. |
png pdf |
Figure 7-b:
Exclusion limit on ${C^{\mathrm {eff}}_{\mathrm {aH}}/{\Lambda ^2}}$ assuming democratic decays of the ALP to dimuons and dielectrons as function of $m_\text {a}$ at 95% CL. Expected and observed 95% CL limit on ${C^{\mathrm {eff}}_{\mathrm {ZH}}/{\Lambda}}$ and ${C^{\mathrm {eff}}_{\mathrm {aH}}/{\Lambda ^2}}$ as function of $m_{\mathrm{a}}$. The dashed black curve is the expected upper limit, with one and two standard-deviation bands shown in green and yellow, respectively. The solid black curve is the observed upper limit. |
| Summary |
| A generic search for a dilepton resonance in Higgs boson decays to the four-lepton final state has been presented. The search considers the two decay topologies ${\mathrm{p}}{\mathrm{p}} \to \mathrm{H} \to \mathrm{Z} \mathrm{X}$ and ${\mathrm{p}}{\mathrm{p}} \to \mathrm{H} \to \mathrm{X} \mathrm{X}$. Without observation of any significant deviation from standard model expectations, the search places strong constraints on model-independent branching fractions and model parameters of two well-motivated models beyond the standard model. In particular, experimental constraints are imposed on products of model independent branching fractions of ${\cal B}(\mathrm{H} \to \mathrm{Z} \mathrm{X})$, ${\cal B}(\mathrm{H} \to \mathrm{X} \mathrm{X})$ and ${\cal B}(\mathrm{X} \to \ell \ell)$, assuming scenarios of flavor-democratic decays of $\mathrm{X}$ to dimuons and dielectrons, exclusive decays of $\mathrm{X}$ to dimuons, and exclusive decays of $\mathrm{X}$ to dielectrons. The search also provides unique constraints on the Higgs-mixing parameter $\kappa < $ 0.003 in a dark photon model with the ${\mathrm{X} \mathrm{X}} $ selection, in Higgs-mixing-dominated scenarios, while searches for ${\mathrm{Z}_{\mathrm{D}}} $ in Drell-Yan processes [51,10] provide better exclusion limits on $\varepsilon$ in kinematic-mixing-dominated scenarios. For the axion-like particle model, strong upper limits are placed on two relevant Wilson coefficients ${C^{\mathrm{eff}}_{\mathrm{ZH}}/{\Lambda}}$ and ${C^{\mathrm{eff}}_{\mathrm{aH}}}$, including the parameter space in which the axion-like particle can explain the anomalous magnetic moment of the muon. |
| References | ||||
| 1 | ATLAS Collaboration | Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC | PLB 716 (2012) 1 | 1207.7214 |
| 2 | CMS Collaboration | Observation of a New Boson at a Mass of 125 GeV with the CMS Experiment at the LHC | PLB 716 (2012) 30 | CMS-HIG-12-028 1207.7235 |
| 3 | D. Curtin, R. Essig, S. Gori, and J. Shelton | Illuminating Dark Photons with High-Energy Colliders | JHEP 02 (2015) 157 | 1412.0018 |
| 4 | D. Curtin et al. | Exotic decays of the 125 GeV Higgs boson | PRD 90 (2014), no. 7, 075004 | 1312.4992 |
| 5 | H. Davoudiasl, H.-S. Lee, I. Lewis, and W. J. Marciano | Higgs Decays as a Window into the Dark Sector | PRD 88 (2013), no. 1, 015022 | 1304.4935 |
| 6 | H. Davoudiasl, H.-S. Lee, and W. J. Marciano | 'Dark' Z implications for Parity Violation, Rare Meson Decays, and Higgs Physics | PRD 85 (2012) 115019 | 1203.2947 |
| 7 | S. Gopalakrishna, S. Jung, and J. D. Wells | Higgs boson decays to four fermions through an abelian hidden sector | PRD 78 (2008) 055002 | 0801.3456 |
| 8 | ATLAS Collaboration | Search for new light gauge bosons in Higgs boson decays to four-lepton final states in $ pp $ collisions at $ \sqrt{s}= $ 8 TeV with the ATLAS detector at the LHC | PRD 92 (2015) 092001 | 1505.07645 |
| 9 | ATLAS Collaboration | Search for Higgs boson decays to beyond-the-Standard-Model light bosons in four-lepton events with the ATLAS detector at $ \sqrt{s}= $ 13 TeV | JHEP 06 (2018) 166 | 1802.03388 |
| 10 | LHCb Collaboration | Search for Dark Photons Produced in 13 $ TeV pp $ Collisions | PRL 120 (2018) 061801 | 1710.02867 |
| 11 | R. Essig et al. | Working Group Report: New Light Weakly Coupled Particles | in Proceedings, 2013 Community Summer Study on the Future of U.S. Particle Physics: Snowmass on the Mississippi (CSS2013): Minneapolis 2013 | 1311.0029 |
| 12 | J. Jaeckel and A. Ringwald | The Low-Energy Frontier of Particle Physics | Ann. Rev. Nucl. Part. Sci. 60 (2010) 405 | 1002.0329 |
| 13 | P. Arias et al. | WISPy Cold Dark Matter | JCAP 1206 (2012) 013 | 1201.5902 |
| 14 | M. Bauer, M. Neubert, and A. Thamm | LHC as an Axion Factory: Probing an Axion Explanation for $ (g-2)_\mu $ with Exotic Higgs Decays | PRL 119 (2017) 031802 | 1704.08207 |
| 15 | H. Georgi, D. B. Kaplan, and L. Randall | Manifesting the Invisible Axion at Low-energies | PL169B (1986) 73 | |
| 16 | M. Bauer, M. Neubert, and A. Thamm | Collider Probes of Axion-Like Particles | JHEP 12 (2017) 044 | 1708.00443 |
| 17 | CMS Collaboration | Search for a Non-Standard-Model Higgs Boson Decaying to a Pair of New Light Bosons in Four-Muon Final States | PLB 726 (2013) 564--586 | CMS-EXO-12-012 1210.7619 |
| 18 | ATLAS Collaboration | Search for new phenomena in events with at least three photons collected in $ pp $ collisions at $ \sqrt{s} = $ 8 TeV with the ATLAS detector | EPJC76 (2016) 210 | 1509.05051 |
| 19 | CMS Collaboration | Search for a very light NMSSM Higgs boson produced in decays of the 125 GeV scalar boson and decaying into $ \tau $ leptons in pp collisions at $ \sqrt{s}= $ 8 TeV | JHEP 01 (2016) 079 | CMS-HIG-14-019 1510.06534 |
| 20 | CMS Collaboration | Search for light bosons in decays of the 125 GeV Higgs boson in proton-proton collisions at $ \sqrt{s}= $ 8 TeV | JHEP 10 (2017) 076 | CMS-HIG-16-015 1701.02032 |
| 21 | CMS Collaboration | The CMS experiment at the CERN LHC | JINST 3 (2008) S08004 | CMS-00-001 |
| 22 | CMS Collaboration | The CMS trigger system | JINST 12 (2017) P01020 | CMS-TRG-12-001 1609.02366 |
| 23 | M. Cacciari, G. P. Salam, and G. Soyez | The anti-$ {k_{\mathrm{T}}} $ jet clustering algorithm | JHEP 04 (2008) 063 | 0802.1189 |
| 24 | M. Cacciari, G. P. Salam, and G. Soyez | FastJet User Manual | EPJC72 (2012) 1896 | 1111.6097 |
| 25 | CMS Collaboration | Particle-flow reconstruction and global event description with the cms detector | JINST 12 (2017) P10003 | CMS-PRF-14-001 1706.04965 |
| 26 | 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 |
| 27 | 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 |
| 28 | 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 |
| 29 | 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 |
| 30 | 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 |
| 31 | R. Frederix and S. Frixione | Merging meets matching in MC@NLO | JHEP 12 (2012) 061 | 1209.6215 |
| 32 | C. Anastasiou et al. | High precision determination of the gluon fusion Higgs boson cross-section at the LHC | JHEP 05 (2016) 058 | 1602.00695 |
| 33 | E. Bagnaschi, G. Degrassi, P. Slavich, and A. Vicini | Higgs production via gluon fusion in the POWHEG approach in the SM and in the MSSM | JHEP 02 (2012) 088 | 1111.2854 |
| 34 | P. Nason | A new method for combining NLO QCD with shower Monte Carlo algorithms | JHEP 11 (2004) 040 | hep-ph/0409146 |
| 35 | S. Frixione, P. Nason, and C. Oleari | Matching NLO QCD computations with Parton Shower simulations: the POWHEG method | JHEP 11 (2007) 070 | 0709.2092 |
| 36 | S. Alioli, P. Nason, C. Oleari, and E. Re | A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX | JHEP 06 (2010) 043 | 1002.2581 |
| 37 | Y. Gao et al. | Spin Determination of Single-Produced Resonances at Hadron Colliders | PRD 81 (2010) 075022 | 1001.3396 |
| 38 | S. Bolognesi et al. | Spin and parity of a single-produced resonance at the LHC | PRD 86 (2012) 095031 | |
| 39 | J. Campbell and T. Neumann | Precision Phenomenology with MCFM | JHEP 12 (2019) 034 | 1909.09117 |
| 40 | T. Sjostrand et al. | An Introduction to PYTHIA 8.2 | CPC 191 (2015) 159 | 1410.3012 |
| 41 | CMS Collaboration | Event generator tunes obtained from underlying event and multiparton scattering measurements | EPJC76 (2016) 155 | CMS-GEN-14-001 1512.00815 |
| 42 | 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 |
| 43 | GEANT4 Collaboration | GEANT4: A Simulation toolkit | NIMA 506 (2003) 250--303 | |
| 44 | J. Allison et al. | Geant4 developments and applications | IEEE Trans. Nucl. Sci. 53 (2006) 270 | |
| 45 | Particle Data Group Collaboration | Review of Particle Physics | PRD98 (2018), no. 3, 030001 | |
| 46 | CMS Collaboration | Measurements of properties of the Higgs boson decaying into the four-lepton final state in pp collisions at $ \sqrt{s}= $ 13 TeV | JHEP 11 (2017) 047 | CMS-HIG-16-041 1706.09936 |
| 47 | T. Junk | Confidence level computation for combining searches with small statistics | NIMA 434 (1999) 435 | hep-ex/9902006 |
| 48 | A. L. Read | Presentation of search results: the $ \mathrm{CL}_\mathrm{s} $ technique | in Durham IPPP Workshop: Advanced Statistical Techniques in Particle Physics, 2002 | |
| 49 | ATLAS and CMS Collaborations | Procedure for the LHC Higgs boson search combination in summer 2011 | ATL-PHYS-PUB-2011-011, CMS NOTE-2011/005 | |
| 50 | G. Cowan, K. Cranmer, E. Gross, and O. Vitells | Asymptotic formulae for likelihood-based tests of new physics | EPJC71 (2011) 1554 | 1007.1727 |
| 51 | CMS Collaboration | Search for a narrow resonance lighter than 200 GeV decaying to a pair of muons in proton-proton collisions at $ \sqrt{s}= $ 13 TeV | PRL 124 (2020), no. 13, 131802 | CMS-EXO-19-018 1912.04776 |
|
|
Compact Muon Solenoid LHC, CERN |
|
|
|
|
|
|