Compact Muon Solenoid
LHC, CERN
Visit us: CMS Public Website, CMS Physics ;
Contact us: CMS Publications Committee
| CMS-EXO-12-053 ; CERN-EP-2016-041 | ||
| Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks | ||
| CMS Collaboration | ||
| 28 February 2016 | ||
| Eur. Phys. J. C 76 (2016) 371 | ||
| Abstract: A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at $ \sqrt{s} = $ 8 TeV. The data correspond to an integrated luminosity of 19.7 fb$^{-1}$. The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and $\mathrm{ t \bar{t} }$ events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95% confidence level for the product of the production cross section and branching fraction $\sigma({ \mathrm{gg}} \to \mathrm{X})\, \mathcal{B}({ \mathrm{X}} \to \mathrm{ H }\mathrm{ H } \to \mathrm{ b \bar{b} }\mathrm{ b \bar{b} })$ range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with a mass scale $\Lambda_\mathrm{R} =$ 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV. | ||
| Links: e-print arXiv:1602.08762 [hep-ex] (PDF) ; CDS record ; inSPIRE record ; HepData record ; CADI line (restricted) ; | ||
| Figures | |
png pdf |
Figure 1:
Simulated $ {m_\mathrm {j}^\mathrm {P}} $ spectrum for spin-0 radion signals, multijet and ${\mathrm{ t } {}\mathrm{ \bar{t} } }$ events, and the spectrum measured in data. Each event contributes twice to the distribution, once per jet. The multijet contribution is rescaled to match the event yield in data, while the signal and ${\mathrm{ t } {}\mathrm{ \bar{t} } }$ spectra are rescaled by the large factors indicated, to be visible in the figure. |
png pdf |
Figure 2:
The efficiencies of H mass requirement and combined H mass and b tagging criteria, for data and signal. Events are required to be in the fiducial region ($ { {| \eta | }} < $ 2.5, $ {p_{\mathrm {T}}} > $ 40 GeV for both jets and $ { {| \Delta \eta _\mathrm {jj} | }} < $ 1.3). The horizontal bar on each data point indicates the width of the bin. |
png pdf |
Figure 3-a:
Observed $ {m_\mathrm {jj}} $ spectrum (black points) in the control region together with the superimposed background fit (red line) and the uncertainty associated with the variation of the slope parameter $a$ (red shaded area) for HPHP (a), HPLP (b), and LPHP (c) categories. |
png pdf |
Figure 3-b:
Observed $ {m_\mathrm {jj}} $ spectrum (black points) in the control region together with the superimposed background fit (red line) and the uncertainty associated with the variation of the slope parameter $a$ (red shaded area) for HPHP (a), HPLP (b), and LPHP (c) categories. |
png pdf |
Figure 3-c:
Observed $ {m_\mathrm {jj}} $ spectrum (black points) in the control region together with the superimposed background fit (red line) and the uncertainty associated with the variation of the slope parameter $a$ (red shaded area) for HPHP (a), HPLP (b), and LPHP (c) categories. |
png pdf |
Figure 4-a:
Observed $ {m_\mathrm {jj}} $ spectrum (black points) compared with a background estimate (black line), obtained in background only hypothesis, for HPHP (top), HPLP (bottom-left), and LPHP (bottom-right) categories. The simulated radion resonances of $ {m_\mathrm {X}} = 1.5$ and 2 TeV are also shown. The lower panel in each plot shows the difference between the number of observed and estimated background events divided by the statistical uncertainty estimated from data. |
png pdf |
Figure 4-b:
Observed $ {m_\mathrm {jj}} $ spectrum (black points) compared with a background estimate (black line), obtained in background only hypothesis, for HPHP (top), HPLP (bottom-left), and LPHP (bottom-right) categories. The simulated radion resonances of $ {m_\mathrm {X}} = 1.5$ and 2 TeV are also shown. The lower panel in each plot shows the difference between the number of observed and estimated background events divided by the statistical uncertainty estimated from data. |
png pdf |
Figure 4-c:
Observed $ {m_\mathrm {jj}} $ spectrum (black points) compared with a background estimate (black line), obtained in background only hypothesis, for HPHP (top), HPLP (bottom-left), and LPHP (bottom-right) categories. The simulated radion resonances of $ {m_\mathrm {X}} = 1.5$ and 2 TeV are also shown. The lower panel in each plot shows the difference between the number of observed and estimated background events divided by the statistical uncertainty estimated from data. |
png pdf |
Figure 5-a:
Observed and expected 95% CL upper limits on the product of cross section of a narrow resonance and the branching fraction $\sigma (\mathrm{g} \mathrm{g} \to {\mathrm {X}} ) \mathcal {B}( {\mathrm {X}} \to \mathrm{ H } \mathrm{ H } \to {\mathrm{ b \bar{b} } } {\mathrm{ b \bar{b} } } )$. Theory curves corresponding to WED models with radion are superimposed. |
png pdf |
Figure 5-b:
Observed and expected 95% CL upper limits on the product of cross section of a narrow resonance and the branching fraction $\sigma (\mathrm{g} \mathrm{g} \to {\mathrm {X}} ) \mathcal {B}( {\mathrm {X}} \to \mathrm{ H } \mathrm{ H } \to {\mathrm{ b \bar{b} } } {\mathrm{ b \bar{b} } } )$. Theory curves corresponding to WED models with radion are superimposed. |
png pdf |
Figure 5-c:
Observed and expected 95% CL upper limits on the product of cross section of a narrow resonance and the branching fraction $\sigma (\mathrm{g} \mathrm{g} \to {\mathrm {X}} ) \mathcal {B}( {\mathrm {X}} \to \mathrm{ H } \mathrm{ H } \to {\mathrm{ b \bar{b} } } {\mathrm{ b \bar{b} } } )$. Theory curves corresponding to WED models with radion are superimposed. |
png pdf |
Figure 6:
Observed and expected 95% CL upper limits on the product of cross section of a narrow resonance and the branching fraction $\sigma (\mathrm{g} \mathrm{g} \to {\mathrm {X}} ) \mathcal {B}( {\mathrm {X}} \to \mathrm{ H } \mathrm{ H } \to {\mathrm{ b \bar{b} } } {\mathrm{ b \bar{b} } } )$. Theory curves corresponding to WED models with radion are also shown. |
png pdf |
Figure 7:
Observed and expected 95% CL upper limits on the product of cross section of a narrow resonance and the branching fraction $\sigma (\mathrm{g} \mathrm{g} \to {\mathrm {X}} ) \mathcal {B}( {\mathrm {X}} \to \mathrm{ H } \mathrm{ H } \to {\mathrm{ b \bar{b} } } {\mathrm{ b \bar{b} } } )$. Theory predictions corresponding to WED models with a radion are also shown. Results from the resolved analysis of Ref. [17] are shown by blue squares. For clarity, only a representative subset of the points are provided from the resolved analysis. The result from this paper is shown in black dots. |
| Tables | |
png pdf |
Table 1:
Summary of selection requirements, with their signal and ${\mathrm{ t } {}\mathrm{ \bar{t} } }$ background efficiencies, and total number of events observed in data. The selection criteria are applied sequentially and the efficiencies are cumulative, except in the last section of the table dedicated to categorization. |
png pdf |
Table 2:
Mass windows used for different signal hypotheses. |
png pdf |
Table 3:
Typical uncertainties in different categories. |
png pdf |
Table 4:
Observed and expected 95% CL upper limits on the product of cross section and the branching fraction $\sigma (\mathrm{g} \mathrm{g} \to {\mathrm {X}} ) \mathcal {B}( {\mathrm {X}} \to \mathrm{ H } \mathrm{ H } \to {\mathrm{ b \bar{b} } } {\mathrm{ b \bar{b} } } )$ for HPHP, HPLP and LPHP categories combined. The one standard deviation on the 95% CL upper limit is also provided. |
| Summary |
| A search is presented for narrow heavy resonances decaying into a pair of Higgs bosons in proton-proton collisions collected by the CMS experiment at $ \sqrt{s} = $ 8 TeV. The full data sample of 19.7 fb$^{-1}$ is explored. The background from multijet and $\mathrm{ t \bar{t} }$ events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. No significant excess of events is observed above the background expected from the SM processes. The results are interpreted as exclusion limits at 95% confidence on the production cross section for ${m_\mathrm{X}} $ between 1.15 and 3.0 TeV, extending significantly beyond 1.5 TeV the reach of previous searches. A radion with scale parameter ${\Lambda_\mathrm{R}} =$ 1 TeV decaying into HH is excluded for 1.15 $ < {m_\mathrm{X}} < $ 1.55 TeV for the first time in direct searches. |
| References | ||||
| 1 | D. de Florian and J. Mazzitelli | Higgs Boson Pair Production at Next-to-Next-to-Leading Order in QCD | PRL 111 (2013) 201801 | 1309.6594 |
| 2 | J. Baglio et al. | The measurement of the Higgs self-coupling at the LHC: theoretical status | JHEP 04 (2013) 151 | 1212.5581 |
| 3 | ATLAS and CMS Collaboration | Combined Measurement of the Higgs Boson Mass in $ pp $ collisions at $ \sqrt{s}=7 $ and 8 TeV with the ATLAS and CMS Experiments | PRL 114 (2015) 191803 | 1503.07589 |
| 4 | A. Djouadi | The Anatomy of electro-weak symmetry breaking. II. The Higgs bosons in the minimal supersymmetric model | PR 459 (2008) 1 | hep-ph/0503173 |
| 5 | R. Barbieri et al. | One or more Higgs bosons? | PRD 88 (2013) 055011 | 1307.4937 |
| 6 | L. Randall and R. Sundrum | A large mass hierarchy from a small extra dimension | PRL 83 (1999) 3370 | hep-ph/9905221 |
| 7 | W. D. Goldberger and M. B. Wise | Modulus Stabilization with Bulk Fields | PRL 83 (1999) 4922 | hep-ph/9907447 |
| 8 | O. DeWolfe, D. Z. Freedman, S. S. Gubser, and A. Karch | Modeling the fifth-dimension with scalars and gravity | PRD 62 (2000) 046008 | hep-th/9909134 |
| 9 | C. Csaki, M. Graesser, L. Randall, and J. Terning | Cosmology of brane models with radion stabilization | PRD 62 (2000) 045015 | hep-ph/9911406 |
| 10 | H. Davoudiasl, J. L. Hewett, and T. G. Rizzo | Phenomenology of the Randall-Sundrum Gauge Hierarchy Model | PRL 84 (2000) 2080 | hep-ph/9909255 |
| 11 | C. Csaki, M. L. Graesser, and G. D. Kribs | Radion dynamics and electroweak physics | PRD 63 (2001) 065002 | hep-th/0008151 |
| 12 | K. Agashe, H. Davoudiasl, G. Perez, and A. Soni | Warped gravitons at the CERN LHC and beyond | PRD 76 (2007) 036006 | hep-ph/0701186 |
| 13 | ATLAS Collaboration | Search for Higgs Boson Pair Production in the $ \gamma\gamma \mathrm{ b \bar{b} } $ Final State using $ pp $ Collision Data at $ \sqrt{s}=8 $ TeV from the ATLAS Detector | PRL 114 (2015) 081802 | 1406.5053 |
| 14 | ATLAS Collaboration | Search for Higgs boson pair production in the $ \mathrm{ b \bar{b} }\mathrm{ b \bar{b} } $ final state from $ pp $ collisions at $ \sqrt{s} = 8 $ TeV with the ATLAS detector | EPJC 75 (2015) 412 | 1506.00285 |
| 15 | ATLAS Collaboration | Searches for Higgs boson pair production in the $ hh\to \mathrm{ b \bar{b} }\tau\tau, \gamma\gamma \mathrm{ W }\mathrm{ W }^*, \gamma\gamma \mathrm{ b \bar{b} }, \mathrm{ b \bar{b} }\mathrm{ b \bar{b} } $ channels with the ATLAS detector | PRD 92 (2015) 092004 | 1509.04670 |
| 16 | CMS Collaboration | Searches for heavy Higgs bosons in two-Higgs-doublet models and for $ t \to ch $ decay using multilepton and diphoton final states in $ pp $ collisions at $ 8 TeV $ | PRD 90 (2014) 112013 | |
| 17 | CMS Collaboration | Search for resonant pair production of Higgs bosons decaying to two bottom quark-antiquark pairs in proton-proton collisions at 8 TeV | PLB 749 (2015) 560 | CMS-HIG-14-013 1503.04114 |
| 18 | CMS Collaboration | Searches for a heavy scalar boson $ \mathrm{H} $ decaying to a pair of 125 GeV Higgs bosons $ \mathrm{ hh } $ or for a heavy pseudoscalar boson $ \mathrm{A} $ decaying to $ \mathrm{Zh} $, in the final states with $ \mathrm{h} \to \tau \tau $ | In press: PLB | CMS-HIG-14-034 1510.01181 |
| 19 | CMS Collaboration | Search for two Higgs bosons in final states containing two photons and two bottom quarks | Submitted to PRD | CMS-HIG-13-032 1603.06896 |
| 20 | ATLAS Collaboration | Search for high-mass diboson resonances with boson-tagged jets in proton-proton collisions at $ \sqrt{s}=8 $ TeV with the ATLAS detector | JHEP 12 (2015) 055 | 1506.00962 |
| 21 | ATLAS Collaboration | Search for production of $ \mathrm{ W }\mathrm{ W }/\mathrm{ W }\mathrm{ Z } $ resonances decaying to a lepton, neutrino and jets in $ \mathrm{ p }\mathrm{ p } $ collisions at $ \sqrt{s}=8 $ TeV with the ATLAS detector | EPJC 75 (2015) 209, , [Erratum: \DOI10.1140/epjc/s10052-015-3593-4] | 1503.04677 |
| 22 | ATLAS Collaboration | Search for resonant diboson production in the $ \mathrm {\ell \ell }{\rm q\bar{q}} $ final state in $ \mathrm{ p }\mathrm{ p } $ collisions at $ \sqrt{s} = 8 $ TeV with the ATLAS detector | EPJC 75 (2015) 69 | 1409.6190 |
| 23 | CMS Collaboration | Search for massive resonances in dijet systems containing jets tagged as W or Z boson decays in pp collisions at $ \sqrt{s} $ = 8 TeV | JHEP 08 (2014) 173 | CMS-EXO-12-024 1405.1994 |
| 24 | CMS Collaboration | Search for massive resonances decaying into pairs of boosted bosons in semi-leptonic final states at $ \sqrt{s} = $ 8 TeV | JHEP 08 (2014) 174 | CMS-EXO-13-009 1405.3447 |
| 25 | ATLAS Collaboration | Combination of searches for $ \mathrm{ W }\mathrm{ W } $, $ \mathrm{ W }\mathrm{ Z } $, and $ \mathrm{ Z }\mathrm{ Z } $ resonances in $ \mathrm{ p }\mathrm{ p } $ collisions at $ \sqrt{s} = 8 $ TeV with the ATLAS detector | In press: PLB | 1512.05099 |
| 26 | J. Brehmer et al. | The Diboson Excess: Experimental Situation and Classification of Explanations; A Les Houches Pre-Proceeding | 1512.04357 | |
| 27 | F. Dias et al. | Combination of Run-1 Exotic Searches in Diboson Final States at the LHC | Submitted to JHEP | 1512.03371 |
| 28 | LHC Higgs Cross Section Working Group Collaboration | Handbook of LHC Higgs Cross Sections: 3. Higgs Properties | 1307.1347 | |
| 29 | P. Archer, M. Carena, A. Carmona, and M. Neubert | Higgs Production and Decay in Models of a Warped Extra Dimension with a Bulk Higgs | JHEP 01 (2015) 060 | 1408.5406 |
| 30 | M. Gouzevitch et al. | Scale-invariant resonance tagging in multijet events and new physics in Higgs pair production | JHEP 07 (2013) 148 | 1303.6636 |
| 31 | B. Cooper, N. Konstantinidis, L. Lambourne, and D. Wardrope | Boosted $ hh \rightarrow b\bar{b}b\bar{b} $: a new topology in searches for TeV-scale resonances at the LHC | PRD 88 (2013) 114005 | 1307.0407 |
| 32 | 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 |
| 33 | CMS Collaboration | The CMS experiment at the CERN LHC | JINST 3 (2008) S08004 | CMS-00-001 |
| 34 | J. Alwall et al. | MadGraph 5: going beyond | JHEP 06 (2011) 128 | 1106.0522 |
| 35 | T. Sj\"ostrand, S. Mrenna, and P. Skands | PYTHIA 6.4 physics and manual | JHEP 05 (2006) 026 | hep-ph/0603175 |
| 36 | S. Hoeche et al. | Matching parton showers and matrix elements | hep-ph/0602031 | |
| 37 | R. Field | Early LHC underlying event data-findings and surprises | 1010.3558v1 | |
| 38 | J. Pumplin et al. | New generation of parton distributions with uncertainties from global QCD analysis | JHEP 07 (2002) 012 | hep-ph/0201195 |
| 39 | GEANT4 Collaboration | GEANT4---a simulation toolkit | NIMA 506 (2003) 250 | |
| 40 | CMS Collaboration | Particle--Flow Event Reconstruction in CMS and Performance for Jets, Taus, and $ E_{\mathrm{T}}^{\text{miss}} $ | CDS | |
| 41 | CMS Collaboration | Commissioning of the Particle--Flow Event Reconstruction with the first LHC collisions recorded in the CMS detector | CDS | |
| 42 | CMS Collaboration | Pileup Removal Algorithms | CMS-PAS-JME-14-001 | CMS-PAS-JME-14-001 |
| 43 | M. Wobisch and T. Wengler | Hadronization corrections to jet cross sections in deep-inelastic scattering | hep-ph/9907280 | |
| 44 | M. Cacciari, G. P. Salam, and G. Soyez | FastJet User Manual | EPJC 72 (2012) 1896 | 1111.6097 |
| 45 | M. Cacciari, G. P. Salam, and G. Soyez | The catchment area of jets | JHEP 04 (2008) 005 | 0802.1188 |
| 46 | M. Cacciari and G. P. Salam | Pileup subtraction using jet areas | PLB 659 (2008) 119 | 0707.1378 |
| 47 | CMS Collaboration | Determination of Jet Energy Calibration and Transverse Momentum Resolution in CMS | JINST 6 (2011) P11002 | CMS-JME-10-011 1107.4277 |
| 48 | CMS Collaboration | Status of the 8 TeV jet energy corrections and uncertainties based on 11 fb$ ^{-1} $ of data in CMS | CDS | |
| 49 | CMS Collaboration | Search for narrow resonances and quantum black holes in inclusive and $ \mathrm{ b } $ tagged dijet mass spectra from $ \mathrm{ p }\mathrm{ p } $ collisions at $ \sqrt{s}=7 $ TeV | JHEP 01 (2013) 013 | CMS-EXO-11-094 1210.2387 |
| 50 | S. D. Ellis, C. K. Vermilion, and J. R. Walsh | Techniques for improved heavy particle searches with jet substructure | PRD 80 (2009) 051501 | 0903.5081 |
| 51 | S. D. Ellis, C. K. Vermilion, and J. R. Walsh | Recombination algorithms and jet substructure: Pruning as a tool for heavy particle searches | PRD 81 (2010) 094023 | 0912.0033 |
| 52 | CMS Collaboration | Studies of jet mass in dijet and W/Z + jet events | JHEP 05 (2013) 090 | CMS-SMP-12-019 1303.4811 |
| 53 | CMS Collaboration | Identification techniques for highly boosted W bosons that decay into hadrons | JHEP 12 (2014) 017 | CMS-JME-13-006 1410.4227 |
| 54 | CMS Collaboration | Identification of b-quark jets with the CMS experiment | JINST 8 (2013) P04013 | CMS-BTV-12-001 1211.4462 |
| 55 | CMS Collaboration | Performance of b tagging at $ \sqrt{s}=8 $ TeV in multijet, $ \mathrm{ t \bar{t} } $ and boosted topology events | CMS-PAS-BTV-13-001 | CMS-PAS-BTV-13-001 |
| 56 | J. Thaler and K. Van Tilburg | Identifying boosted objects with N-subjettiness | JHEP 03 (2011) 015 | 1011.2268 |
| 57 | J. Thaler and K. Van Tilburg | Maximizing Boosted Top Identification by Minimizing N-subjettiness | JHEP 02 (2012) 093 | 1108.2701 |
| 58 | I. W. Stewart, F. J. Tackmann, and W. J. Waalewijn | $ N $ Jettiness: An Inclusive Event Shape to Veto Jets | PRL 105 (2010) 092002 | 1004.2489 |
| 59 | CMS Collaboration | Search for resonances in the dijet mass spectrum from 7 TeV pp collisions at CMS | PLB 704 (2011) 123 | CMS-EXO-11-015 1107.4771 |
| 60 | M. Czakon, P. Fiedler, and A. Mitov | Total Top-Quark Pair-Production Cross Section at Hadron Colliders through $ O(\alpha^4_{S}) $ | PRL 110 (2013) 252004 | 1303.6254 |
| 61 | CMS Collaboration | Search for exotic resonances decaying into $ WZ/ZZ $ in $ \mathrm{ p }\mathrm{ p } $ collisions at $ \sqrt{s}=7 $ TeV | JHEP 02 (2013) 036 | CMS-EXO-12-014 1211.5779 |
| 62 | CMS Collaboration | CMS Luminosity Based on Pixel Cluster Counting - Summer 2013 Update | CMS-PAS-LUM-13-001 | CMS-PAS-LUM-13-001 |
| 63 | A. L. Read | Presentation of search results: the $ CL_s $ technique | JPG 28 (2002) 2693 | |
| 64 | T. Junk | Confidence level computation for combining searches with small statistics | NIMA 434 (1999) 435 | hep-ex/9902006 |
|
|
Compact Muon Solenoid LHC, CERN |
|
|
|
|
|
|