CMS-PAS-B2G-16-023 | ||
Search for diboson resonances in the $ 2 \ell 2 \nu $ final state | ||
CMS Collaboration | ||
May 2017 | ||
Abstract: A search for a heavy resonances decaying to a pair of Z bosons is presented. This search selects events containing two oppositely charged leptons (electrons or muons) consistent with the decay of a Z boson, and large missing transverse momentum, which is interpreted as the decay of a second Z boson to two neutrinos. The analysis uses data collected in 2016 with the CMS detector, corresponding to 35.9 fb$^{-1}$ of integrated luminosity of proton-proton collisions with a center-of-mass energy of 13 TeV at the LHC. The search is performed using the transverse mass spectrum of the two leptons and the missing transverse momentum system, where a new heavy resonance can be expected to produce a Jacobian Edge corresponding to its invariant mass at the TeV scale. The theoretical hypothesis of a narrow width spin-2 bulk graviton is examined. The observed upper limits are consistent with the SM backgrounds prediction. For $\tilde{k}=$ 0.5, the mass region below 800 GeV is excluded at 95% confidence level. | ||
Links:
CDS record (PDF) ;
inSPIRE record ;
CADI line (restricted) ;
These preliminary results are superseded in this paper, JHEP 03 (2018) 003. The superseded preliminary plots can be found here. |
Figures | |
png pdf |
Figure 1:
Feynman diagram for the production of a generic resonance X produced via gluon fusion and decaying to the ZZ final state considered in this study. |
png pdf |
Figure 2:
The $p_{\mathrm {T}}^{\mathrm {Z}}$ distributions for electron (left) and muon (right) channels comparing data and data-driven background modeling in the SR. The lower panels show the ratio of data to the prediction for background, where the error band shows only the statistical uncertainties of the data over background ratio. Signal cross-sections times branching fraction are arbitrarily normalized to 1 pb. |
png pdf |
Figure 2-a:
The $p_{\mathrm {T}}^{\mathrm {Z}}$ distributions for the electron channel comparing data and data-driven background modeling in the SR. The lower panel shows the ratio of data to the prediction for background, where the error band shows only the statistical uncertainties of the data over background ratio. Signal cross-sections times branching fraction are arbitrarily normalized to 1 pb. |
png pdf |
Figure 2-b:
The $p_{\mathrm {T}}^{\mathrm {Z}}$ distributions for the muon channel comparing data and data-driven background modeling in the SR. The lower panel shows the ratio of data to the prediction for background, where the error band shows only the statistical uncertainties of the data over background ratio. Signal cross-sections times branching fraction are arbitrarily normalized to 1 pb. |
png pdf |
Figure 3:
The $E_{\mathrm {T}}^{\mathrm {miss}}$ for electron (left) and muon (right) channels comparing data and background models. The lower panels show the ratio of data to the prediction for background. The signal cross-sections times branching fraction are arbitrarily normalized to 1 pb. |
png pdf |
Figure 3-a:
The $E_{\mathrm {T}}^{\mathrm {miss}}$ for the electron channel comparing data and background models. The lower panel shows the ratio of data to the prediction for background. The signal cross-sections times branching fraction are arbitrarily normalized to 1 pb. |
png pdf |
Figure 3-b:
The $E_{\mathrm {T}}^{\mathrm {miss}}$ for the muon channel comparing data and background models. The lower panel shows the ratio of data to the prediction for background. The signal cross-sections times branching fraction are arbitrarily normalized to 1 pb. |
png pdf |
Figure 4:
The $M_{\mathrm {T}}$ distributions for electron (ee, left) and muon ($\mu \mu $, right) channels comparing data and data-driven background modeling after fitting only the background modeling to the data (Post-fit B-only). A model of the expected distribution for a spin-2 bulk graviton with $M_{\mathrm {G}}= $ 1 TeV is shown after normalization to a cross section of 1 pb. The uncertainty bands on the ratio plots show the systematic uncertainties, while the statistical uncertainty on the data is reflected by the error bars. The lower panels show the ratio of data to the prediction for background. |
png pdf |
Figure 4-a:
The $M_{\mathrm {T}}$ distributions for the electron (ee) channel comparing data and data-driven background modeling after fitting only the background modeling to the data (Post-fit B-only). A model of the expected distribution for a spin-2 bulk graviton with $M_{\mathrm {G}}= $ 1 TeV is shown after normalization to a cross section of 1 pb. The uncertainty bands on the ratio plots show the systematic uncertainties, while the statistical uncertainty on the data is reflected by the error bars. The lower panel shows the ratio of data to the prediction for background. |
png pdf |
Figure 4-b:
The $M_{\mathrm {T}}$ distributions for the muon ($\mu \mu $) channel comparing data and data-driven background modeling after fitting only the background modeling to the data (Post-fit B-only). A model of the expected distribution for a spin-2 bulk graviton with $M_{\mathrm {G}}= $ 1 TeV is shown after normalization to a cross section of 1 pb. The uncertainty bands on the ratio plots show the systematic uncertainties, while the statistical uncertainty on the data is reflected by the error bars. The lower panel shows the ratio of data to the prediction for background. |
png pdf |
Figure 5:
Expected and observed limits on the production cross-section of a new spin-2 heavy resonance $\mathrm {X \to ZZ}$ assuming zero mass width based on the combined analysis of the electron and muon channels. Expected production cross sections are also shown for the benchmark bulk graviton model for two values of the curvature parameter $\tilde{k}$. |
png pdf |
Figure 6:
Expected and observed limits on the production cross-section of a new spin-2 heavy resonance $\mathrm {X \to ZZ}$ assuming zero mass width separately for the electron (ee, left) and muon ($\mu \mu $, right) channels. |
png pdf |
Figure 6-a:
Expected and observed limits on the production cross-section of a new spin-2 heavy resonance $\mathrm {X \to ZZ}$ assuming zero mass width separately for the electron (ee) channel. |
png pdf |
Figure 6-b:
Expected and observed limits on the production cross-section of a new spin-2 heavy resonance $\mathrm {X \to ZZ}$ assuming zero mass width separately for the muon ($\mu \mu $) channel. |
Tables | |
png pdf |
Table 1:
Summary of the uncertainties for the electron channel and the muon channel that are included in the limit setting. In the table, "-'' means does not apply and "(-)'' stands for negligibly small. "Signal'' refers to the hypothetical narrow width spin-2 bulk graviton sample with a mass of 1 TeV. |
png pdf |
Table 2:
Event yields for different background contributions and those observed in data for the electron and muon channels. |
Summary |
A search for the production of new resonances has been performed in events with a Z boson and missing transverse momentum, using a data set corresponding to an integrated luminosity of 35.9 fb$^{-1}$ of pp collisions at a center-of-mass energy of 13 TeV. The observed data are in general agreement with expectations from SM processes and the results are analyzed to obtain limits for the production of a narrow width spin-2 bulk graviton. For a resonance X limits on the cross section times branching ratio for the process $\mathrm{X \to ZZ}$ are determined at the 95% confidence level for 600 $ <\mathrm{m_X}< $ 2500 GeV. For the narrow width resonances with $\tilde{k}= $ 0.5, the masses below 800 GeV are excluded at 95% CL, which is presently the highest upper limit for this hypothesis in ZZ final state. In comparison with the all hadronic channel results at CMS using 2016 full dataset [17], the results from the $2\ell 2\nu$ channel show a higher sensitivity in the low mass region (below 1.5 TeV), but a lower sensitivity in the high mass region (above 1.5 TeV) due to limited statistics. |
References | ||||
1 | 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 |
2 | CMS Collaboration | Observation of a new boson with mass near 125 GeV in pp collisions at $ \sqrt{s} = $ 7 and 8 TeV | JHEP 06 (2013) 081 | CMS-HIG-12-036 1303.4571 |
3 | 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 |
4 | S. Weinberg | Implications of dynamical symmetry breaking | PRD 13 (1976) 974 | |
5 | S. Weinberg | Implications of dynamical symmetry breaking: An addendum | PRD 19 (1979) 1277 | |
6 | L. Susskind | Dynamics of spontaneous symmetry breaking in the Weinberg--Salam theory | PRD 20 (1979) 2619 | |
7 | D. B. Kaplan and H. Georgi | SU(2) x U(1) breaking by vacuum misalignment | PLB 136 (1984) 183 | |
8 | R. Contino, T. Kramer, M. Son, and R. Sundrum | Warped/composite phenomenology simplified | JHEP 05 (2007) 074 | hep-ph/0612180 |
9 | G. F. Giudice, C. Grojean, A. Pomarol, and R. Rattazzi | The strongly-interacting light Higgs | JHEP 06 (2007) 045 | hep-ph/0703164 |
10 | CMS Collaboration | Search for a W$ ^\prime $ or Techni-$ \rho $ Decaying into WZ in pp Collisions at $ \sqrt{s}= $ 7 TeV | PRL 109 (2012) 141801 | CMS-EXO-11-041 1206.0433 |
11 | CMS Collaboration | Search for a narrow spin-2 resonance decaying to a pair of Z vector bosons in the semileptonic final state | PLB 718 (2013) 1208 | CMS-EXO-11-102 1209.3807 |
12 | CMS Collaboration | Search for exotic resonances decaying into WZ/ZZ in pp collisions at $ \sqrt{s}= $ 7 TeV | JHEP 02 (2013) 036 | CMS-EXO-12-014 1211.5779 |
13 | CMS Collaboration | Search for heavy resonances in the W/Z-tagged dijet mass spectrum in pp collisions at 7 TeV | PLB 723 (2013) 280 | CMS-EXO-11-095 1212.1910 |
14 | CMS Collaboration | Search for dark matter and unparticles in events with a Z boson and missing transverse momentum in proton-proton collisions at $ sqrt{s} = $ 13 TeV | CMS-EXO-16-010 1701.02042 |
|
15 | CMS Collaboration | Search for heavy resonances decaying into a $ \mathrm{Z} $ boson and a $ \mathrm{W} $ boson in the $ \ell^+\ell^-\mathrm{q}\bar{\mathrm{q}} $ final state | ||
16 | CMS Collaboration | Search for a heavy scalar boson decaying into a pair of Z bosons in the $ 2\ell 2\nu $ final state | ||
17 | CMS Collaboration | Search for massive resonances decaying into WW, WZ, ZZ, qW and qZ in the dijet final state at $ \sqrt{s}= $ 13 TeV | ||
18 | CMS Collaboration | Search for heavy resonances decaying into a vector boson and a Higgs boson in hadronic final states with 2016 data | ||
19 | CMS Collaboration | Search for heavy resonances decaying to a pair of Higgs bosons in the four b quark final state in proton-proton collisions at 13 TeV | ||
20 | ATLAS Collaboration | Search for new particles decaying to $ Z Z $ using final states with leptons and jets with the ATLAS detector in $ \sqrt{s}= $ 7 TeV proton-proton collisions | PLB 712 (2012) 331 | 1203.0718 |
21 | ATLAS Collaboration | Search for resonant WZ production in the $ \mathrm{WZ} \to \ell \nu \ell^\prime\ell^\prime $ channel in $ \sqrt{s}= $ 7 TeV pp collisions with the ATLAS detector | PRD 85 (2012) 112012 | 1204.1648 |
22 | ATLAS Collaboration | Search for new phenomena in the WW to $ \ell \nu \ell^\prime\nu^\prime $ final state in pp collisions at $ \sqrt{s}= $ 7 TeV with the ATLAS detector | PLB 718 (2013) 860 | 1208.2880 |
23 | ATLAS Collaboration | Search for resonant diboson production in the $ \ell\nu jj $ decay channels with the ATLAS detector at 7 TeV | PRD 87 (2013) 112006 | 1305.0125 |
24 | C. Delaunay et al. | Ultra visible warped model from flavor triviality and improved naturalness | PRD 83 (2011) 115003 | 1007.0243 |
25 | K. Agashe, A. Delgado, M. J. May, and R. Sundrum | RS1, custodial isospin and precision tests | JHEP 08 (2003) 050 | hep-ph/0308036 |
26 | N. Arkani-Hamed, S. Dimopoulos, and G. R. Dvali | The Hierarchy problem and new dimensions at a millimeter | PLB429 (1998) 263--272 | hep-ph/9803315 |
27 | I. Antoniadis, N. Arkani-Hamed, S. Dimopoulos, and G. R. Dvali | New dimensions at a millimeter to a Fermi and superstrings at a TeV | PLB436 (1998) 257--263 | hep-ph/9804398 |
28 | L. Randall and R. Sundrum | A large mass hierarchy from a small extra dimension | PRL 83 (1999) 3370 | hep-ph/9905221 |
29 | K. Agashe, H. Davoudiasl, G. Perez, and A. Soni | Warped gravitons at the LHC and beyond | PRD 76 (2007) 036006, , [Erratum in preparation. Private communication with the authors] | hep-ph/0701186 |
30 | 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 |
31 | O. Antipin, D. Atwood, and A. Soni | Search for RS gravitons via $ W_L W_L $ decays | PLB 666 (2008) 155 | 0711.3175 |
32 | A. Oliveira | Gravity particles from Warped Extra Dimensions, predictions for LHC | 1404.0102 | |
33 | CMS Collaboration | The CMS experiment at the CERN LHC | JINST 3 (2008) S08004 | CMS-00-001 |
34 | CMS Collaboration | Particle-Flow Event Reconstruction in CMS and Performance for Jets, Taus, and MET | CMS-PAS-PFT-09-001 | |
35 | CMS Collaboration | Commissioning of the Particle-flow Event Reconstruction with the first LHC collisions recorded in the CMS detector | CMS-PAS-PFT-10-001 | |
36 | CMS Collaboration | Performance of Electron Reconstruction and Selection with the CMS Detector in Proton-Proton Collisions at $ \sqrt{s} = $ 8 TeV | JINST 10 (2015), no. 06, P06005 | CMS-EGM-13-001 1502.02701 |
37 | 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 |
38 | CMS Collaboration | Jet energy scale and resolution in the CMS experiment in pp collisions at 8 TeV | Submitted to: JINST (2016) | CMS-JME-13-004 1607.03663 |
39 | 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 |
40 | T. Sj\"ostrand, S. Mrenna, and P. Skands | PYTHIA 6.4 physics and manual | JHEP 05 (2006) 026 | hep-ph/0603175 |
41 | NNPDF Collaboration | Parton distributions for the LHC Run II | JHEP 04 (2015) 040 | 1410.8849 |
42 | GEANT4 Collaboration | GEANT4: A Simulation toolkit | NIMA506 (2003) 250--303 | |
43 | Y. Li and F. Petriello | Combining QCD and electroweak corrections to dilepton production in FEWZ | PRD86 (2012) 094034 | 1208.5967 |
44 | CMS Collaboration | Measurements of inclusive and differential $ \mathrm{Z} $ boson production cross sections in $ \mathrm{p}\mathrm{p} $ collisions at $ \sqrt{s}= $ 13 TeV | CMS-PAS-SMP-15-011 | CMS-PAS-SMP-15-011 |
45 | M. Grazzini, S. Kallweit, and D. Rathlev | ZZ production at the LHC: fiducial cross sections and distributions in NNLO QCD | PLB750 (2015) 407--410 | 1507.06257 |
46 | A. Bierweiler, T. Kasprzik, and J. H. Kahn | Vector-boson pair production at the LHC to $ \mathcal{O}(\alpha^3) $ accuracy | JHEP 12 (2013) 071 | 1305.5402 |
47 | S. Gieseke, T. Kasprzik, and J. H. Kahn | Vector-boson pair production and electroweak corrections in HERWIG++ | EPJC74 (2014), no. 8 | 1401.3964 |
48 | T. Junk | Confidence level computation for combining searches with small statistics | NIMA434 (1999) 435 | hep-ex/9902006 |
49 | A. L. Read | Presentation of search results: The CL(s) technique | JPG28 (2002) 2693 | |
50 | ATLAS Collaboration | Procedure for the LHC Higgs boson search combination in summer 2011 | CMS-NOTE-2011-005 | |
51 | G. Cowan, K. Cranmer, E. Gross, and O. Vitells | Asymptotic formulae for likelihood-based tests of new physics | EPJC71 (2011) 1554 | 1007.1727 |
Compact Muon Solenoid LHC, CERN |