Search for resonances and quantum black holes …2 Wide jets (R = 1.1) Highest Dijet Mass Event Mjj...
1
Search for resonances and quantum black holes using the dijet mass spectrum in pp collisions at √s = 8 TeV Emine Gurpinar On the behalf of CMS Collaboration http://arxiv.org/abs/1501.04198 • Search for • Narrow dijet resonances decaying to quark-quark( qq ), quark-gluon( qg ), gluon- gluon( gg ) where the resonance width is negligible compared to the experimental dijet mass resolution , • Narrow qq and gg resonances using the observed dijet resonance line shape of the RS graviton model for k/MPl = 0.1, which corresponds to a natural width equal to 1.5% of the resonance mass. • Narrow resonances decaying to b quarks, • Wide dijet resonances that are not narrow compared to the detector resolution, in qq and gg final states, • Wide qq and gg resonances using the dijet resonance line shape of the RS graviton model with larger values of k/MPl, which corresponds to natural widths varying between 5% and 30% of the resonance mass. • Quantum black holes decaying to two jets • Several benchmark models of dijet resonances produced via the s channel Wide jet algorithm: Require two leading AK5 PF jets to have pT>30 GeV and |η|<2.5, and to pass tight PF jet ID All other AK5 PF jets with pT>30 GeV, |η|<2.5, and passing loose PF jet ID added to the closest leading jet if within ΔR<Rwide=1.1 Wide jet algorithm developed to improve the dijet mass resolution for heavy resonances Dijet system = two leading wide jets which satisfies |Δη|<1.3 and reconstructed in the region |η|<2.5 (suppresses QCD background) Events with dijet mass (formed from the two wide jets) > 890 GeV because of 99.7% efficiency of L1 and HLT. Applying the loose version of the combined secondary-vertex (CSV) algorithm to the two leading jets to categorized as 0b, 1b, or 2b according to the algorithm output. 4 TeV 4 TeV There is no significant excess in data with respect to the background prediction We proceed to set upper limits on the cross section of new resonances. Bayesian formalism with a uniform prior is used for the cross section. The signal comes from our dijet resonance shapes Background is fixed to the best The systematic uncertainties are included in the limit as nuisance parameters. These are: Jet energy Scale Jet energy resolution Background shape Luminosity b-tagging scale factors (applied only in the b-jet dedicated search) Fit the following parameterization to the data and compare to QCD prediction using the full CMS simulation and signal resonances. where m is the dijet mass, four free Four parameters P 0 , P 1 , P 2 , P 3 and √s = 8 TeV . Inclusive dijet mass spectrum from wide jets (points) compared to a fit (solid line) and to predictions including detector simulation of multijet events and signal resonances. The predicted multijet shape has been normalized to the data. The vertical error bars are statistical only and the horizontal error bars are the bin widths. The bin-by-bin fit residuals normalized to the statistical uncertainty of the data, (data-fit)/σ data , are shown. Highest Dijet Mass Event Mjj = 5.15TeV Results of a search for dijet resonances and quantum black hole has been presented using inclusive and b-tagged dijet mass spectra. No evidence particle is found therefore we set upper limits at 95%CL on the product of the cross section, branching fraction into dijets, and acceptance. This results with 8 TeV full data set of pp collisions with CMS detector at LHC (19.7 fb-1) were approved (PAS EXO 2012-059) for Moriond2013 conference; a paper has been produced and accepted by Phys. Rev. D. Reference: http://arxiv.org/abs/1501.04198 • Two set of samples: qq G qq, gg G gg, where G is the RS Graviton model implemented in Pythia8 • The relative width of the resonance depend on the k/MPl parameter of the RS Graviton model • The width-to-mass ratio of the resonance is Γ/M ≈ 1.4 × (k/MPl) 2 . • The range of relative widths for the resonances are (Γ/M) of 0.001%, 1.5% (narrow resonance), 5%, 10%, 15%, 20%, 25%, 30% . • The limits are quoted in a range of masses and widths that satisfies two conditions: • at low mass, the core of the signal shape is preserved after the trigger selection mjj > 890 GeV, • at high mass, the low-mass tails in the signal shape due to PDFs do not contribute significantly to the limit value (i.e. removing the low-mass tails, by truncating the signal shape at 85% of the nominal resonance mass, changes the expected limit by maximally 30%, corresponding to the typical uncertainty on the expected limits). • The inclusive dijet search is also sensitive to quantum black holes primarily decaying to pair of jets, can be interpreted in terms of QBH production in models with large (n ≥ 2) or warped (n = 1) dimensions, where n is the number of extra dimensions. • The peak position is related to the minimum mass of QBHs, Mmin QBH. • The low-mass dijet tails are due to detector resolution effects. • The shape is almost independent of the number of extra dimensions n and the fundamental Planck scale MD. • The cross section limits are presented only for Mmin QBH ≥ MD, for different values of MD. (pb/GeV) jj /dm σ d -8 10 -7 10 -6 10 -5 10 -4 10 -3 10 -2 10 -1 10 1 10 Data Fit QCD MC JES uncertainty CMS Wide jets (R = 1.1) | < 1.3 jj η ∆ | < 2.5 & | η | (8 TeV) -1 19.7 fb q* (3.6 TeV) W' (1.9 TeV) Dijet mass (GeV) 1000 2000 3000 4000 5000 Residuals -4 -2 0 2 4 (pb/GeV) jj /dm σ d -8 10 -7 10 -6 10 -5 10 -4 10 -3 10 -2 10 -1 10 1 10 χ ± ± ± ± χ ± ± ± ± χ ± ± ± ± Data Fit CMS (8 TeV) -1 19.7 fb b* (1.8 TeV) Z' (2.2 TeV) G (2.8 TeV) Z' (3.2 TeV) 0 b tags Wide jets (R = 1.1) | < 1.3 jj η ∆ | < 2.5 & | η | Dijet mass (GeV) 1000 2000 3000 4000 5000 Residuals -2 0 2 (pb/GeV) jj /dm σ d -8 10 -7 10 -6 10 -5 10 -4 10 -3 10 -2 10 -1 10 1 10 χ ± ± ± ± χ ± ± ± ± χ ± ± ± ± Data Fit CMS (8 TeV) -1 19.7 fb b* (1.8 TeV) Z' (2.2 TeV) G (2.8 TeV) Z' (3.2 TeV) 1 b tag Wide jets (R = 1.1) | < 1.3 jj η ∆ | < 2.5 & | η | Dijet mass (GeV) 1000 2000 3000 4000 5000 Residuals -2 0 2 (pb/GeV) jj /dm σ d -8 10 -7 10 -6 10 -5 10 -4 10 -3 10 -2 10 -1 10 1 10 χ ± ± ± ± χ ± ± ± ± χ ± ± ± ± Data Fit CMS (8 TeV) -1 19.7 fb b* (1.8 TeV) Z' (2.2 TeV) G (2.8 TeV) Z' (3.2 TeV) 2 b tags Wide jets (R = 1.1) | < 1.3 jj η ∆ | < 2.5 & | η | Dijet mass (GeV) 1000 2000 3000 4000 5000 Residuals -2 0 2 Dijet mass (GeV) 1000 2000 3000 4000 5000 6000 ) -1 Probability density (GeV 0 1 2 3 4 5 -3 10 × Wide jets (R = 1.1) | < 1.3 jj η ∆ | < 2.5 & | η | /M=1.5% Γ M /M=10% Γ M CMS Simulation (8 TeV) qq → RS graviton → qq 1 TeV 2 TeV 3 TeV 4 TeV 5 TeV 1 TeV 2 TeV 3 TeV 4 TeV 5 TeV Dijet mass (GeV) 1000 2000 3000 4000 5000 6000 ) -1 Probability density (GeV 0 1 2 3 4 5 -3 10 × Wide jets (R = 1.1) | < 1.3 jj η ∆ | < 2.5 & | η | /M=1.5% Γ M /M=10% Γ M CMS Simulation (8 TeV) gg → RS graviton → gg 1 TeV 2 TeV 3 TeV 4 TeV 5 TeV 1 TeV 2 TeV 3 TeV 4 TeV 5 TeV qq resonance mass (GeV) 1000 2000 3000 4000 5000 (pb) A × B × σ -4 10 -3 10 -2 10 -1 10 1 10 0.001% 1.5% 5% 10% 15% 20% 25% 30% CMS (8 TeV) -1 19.7 fb / M Γ gg resonance mass (GeV) 1000 2000 3000 4000 5000 (pb) A × B × σ -4 10 -3 10 -2 10 -1 10 1 10 0.001% 1.5% 5% 10% 15% 20% 25% 30% CMS (8 TeV) -1 19.7 fb / M Γ Dijet mass (GeV) 1000 2000 3000 4000 5000 6000 7000 8000 ) -1 Probability density (GeV 0.5 1 1.5 2 2.5 -3 10 × Wide jets (R = 1.1) | < 1.3 jj η ∆ | < 2.5 & | η | CMS Simulation (8 TeV) = 2 TeV min QBH M = 3 TeV min QBH M = 4 TeV min QBH M = 5 TeV min QBH M = 6.5 TeV min QBH M (GeV) min QBH M 2000 3000 4000 5000 6000 (pb) A × B × σ -7 10 -6 10 -5 10 -4 10 -3 10 -2 10 -1 10 1 10 2 10 3 10 n=1 n=2 n=3 n=4 n=5 n=6 CMS (8 TeV) -1 19.7 fb 95% CL upper limit = 2TeV D M (GeV) min QBH M 3000 3500 4000 4500 5000 5500 6000 6500 (pb) A × B × σ -7 10 -6 10 -5 10 -4 10 -3 10 -2 10 -1 10 1 10 2 10 n=1 n=2 n=3 n=4 n=5 n=6 95% CL upper limit CMS (8 TeV) -1 19.7 fb = 3TeV D M (GeV) min QBH M 5000 5200 5400 5600 5800 6000 6200 6400 (pb) A × B × σ -7 10 -6 10 -5 10 -4 10 -3 10 -2 10 -1 10 n=1 n=2 n=3 n=4 n=5 n=6 95% CL upper limit CMS (8 TeV) -1 19.7 fb = 5TeV D M BH Mass (GeV) 6000 6100 6200 6300 6400 6500 (pb) A × B × Cross Section -7 10 -6 10 -5 10 -4 10 -3 10 -2 10 -1 10 1 10 2 10 3 10 = 6TeV D n = 1, M = 6TeV D n = 2, M = 6TeV D n = 3, M = 6TeV D n = 4, M = 6TeV D n = 5, M = 6TeV D n = 6, M Observed 95% CL Upper Limit CMS = 8 TeV s -1 L= 19.71 fb S8 resonance mass (GeV) 1000 1500 2000 2500 3000 3500 4000 4500 (pb) A × B × σ -3 10 -2 10 -1 10 1 95% CL upper limit gluon-gluon CMS (8 TeV) -1 19.7 fb S8 Axigluon/coloron mass (GeV) 1000 1500 2000 2500 3000 3500 4000 4500 (pb) A × B × σ -3 10 -2 10 -1 10 1 95% CL upper limit quark-quark CMS (8 TeV) -1 19.7 fb Axigluon/coloron qq resonance mass (GeV) 1000 2000 3000 4000 5000 (pb) A × B × σ -5 10 -4 10 -3 10 -2 10 -1 10 1 10 2 10 3 10 4 10 CMS (8 TeV) -1 19.7 fb 95% CL upper limits Observed Expected σ 1 ± σ 2 ± Axigluon/coloron Scalar diquark W' SSM Z' SSM qg resonance mass (GeV) 1000 2000 3000 4000 5000 (pb) A × B × σ -5 10 -4 10 -3 10 -2 10 -1 10 1 10 2 10 3 10 4 10 CMS (8 TeV) -1 19.7 fb 95% CL upper limits Observed Expected σ 1 ± σ 2 ± String Excited quark gg resonance mass (GeV) 1000 2000 3000 4000 5000 (pb) A × B × σ -5 10 -4 10 -3 10 -2 10 -1 10 1 10 2 10 3 10 4 10 CMS (8 TeV) -1 19.7 fb 95% CL upper limits Observed Expected σ 1 ± σ 2 ± S8 RS graviton mass (GeV) 1200 1400 1600 1800 2000 (pb) A × B × σ -2 10 -1 10 1 10 95% CL upper limits Observed Expected σ 1 ± σ 2 ± CMS (8 TeV) -1 19.7 fb (k/M=0.1) RS graviton Resonance mass (GeV) 1000 2000 3000 4000 Tagging efficiency 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 tags 1 tag 2 tags CMS (8 TeV) Simulation bb → G Resonance mass (GeV) 1000 2000 3000 4000 Tagging efficiency 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 tags 1 tag 2 tags CMS (8 TeV) Simulation bg → b* Resonance mass (GeV) 1000 2000 3000 4000 Tagging efficiency 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 tags 1 tag 2 tags CMS (8 TeV) Simulation qq/gg (q=u,d,s) → G Tagging efficiencies for 0, 1, and 2 b tags selections as a function of the resonance mass for bb, bg, and qq/gg (where q=u,d,s) decay modes. The hatched regions represent uncertainties in the tagging efficiencies due to the variation of the b-tag scale factors within their uncertainties. The observed 95% CL upper limits on σ × B × A for resonances decaying into qq/qg/gg final state (points and solid lines) are compared to the expected limits (dot-dashed dark lines) and their variation at the 1σ and 2σ levels (shaded bands). Predicted cross sections of various narrow resonances are also shown. The signal shape for the RS model is obtained weighting the shapes for qq and gg final states according to LO calculations of the relative branching fractions. Resonance mass (GeV) 1000 2000 3000 4000 5000 (pb) A × B × σ -5 10 -4 10 -3 10 -2 10 -1 10 1 10 2 10 3 10 4 10 CMS (8 TeV) -1 19.7 fb 95% CL upper limits gluon-gluon quark-gluon quark-quark String Excited quark Axigluon/coloron Scalar diquark S8 W' SSM Z' SSM RS graviton (k/M=0.1) Resonance mass (GeV) 1000 1500 2000 2500 3000 3500 4000 (pb) A × B × σ -4 10 -3 10 -2 10 -1 10 1 10 jj) → B(X bb) → B(X = bb f gg/bb] → 95% CL upper limits [X = 0.1) bb RS graviton (f = 1.0 bb f = 0.75 bb f = 0.5 bb f = 0.1 bb f 0, 1, 2 b tags CMS (8 TeV) -1 19.7 fb Resonance mass (GeV) 1000 1500 2000 2500 3000 3500 4000 (pb) A × B × σ -4 10 -3 10 -2 10 -1 10 1 10 jj) → B(X bb) → B(X = bb f qq/bb] → 95% CL upper limits [X = 0.2) bb Z' (f = 1.0 bb f = 0.75 bb f = 0.5 bb f = 0.2 bb f 0, 1, 2 b tags CMS (8 TeV) -1 19.7 fb b* resonance mass (GeV) 1000 1500 2000 2500 3000 3500 4000 (pb) A × B × σ -4 10 -3 10 -2 10 -1 10 1 10 95% CL upper limits Observed Expected σ 1 ± σ 2 ± b* 0, 1, 2 b tags CMS (8 TeV) -1 19.7 fb • It is no longer appropriate to use the narrow resonance to set limits on Axigluons/Colorons and S8 since They are wide resonances. • The width of the Axigluon/Coloron is Gamma=alphas_s*M, the S8 resonance is (5/6)*model is alpha_s(M). The width is between %5 and %10. • We have experimental limits only for 5% and 10% resonance so we perform a linear interpolation between 5% and 10% limits for each mass value. • We built a new qq experimental limit curve for the axigluon/coloron (such that at each mass value the limit correspond to a relative width equal to alpha_s(M)) and a new gg experimental limit curve for the S8 resonance (such that at each mass value the limit correspond to a relative width equal to 5/6*alpha_s(M)) Observed 95% CL upper limits on σ × B × A as a function of the minimum mass of quantum black holes, compared to theoretical predictions for a quantum gravity scale of M D = 2 TeV, M D = 3 TeV, M D = 4 TeV, and M D =5 TeV, with the number of extra dimensions n ranging from one to six . Measured number of events in data number of events from signal Expected number of events from background Dijet mass spectra (points) in different b-tag multiplicity bins compared to a fit (solid line). Predictions for RS graviton, Z’, and excited b- quark signal spectra are also shown. The vertical error bars are statistical only and the horizontal error bars are the bin widths. The bin- by-bin fit residuals normalized to the statistical uncertainty of the data, (data-fit)/σ data , are shown at the bottom of each plot. Observed and expected 95% CL upper limits on σBA with systematic uncertainties included, for b ∗ → bg resonances, compared with the LO theoretical cross section for excited b-quark production. The observed 95% CL upper limits on σBA for narrow dijet resonances. Left: limit on gluon-gluon, quark-gluon, and quark-quark narrow resonances from the inclusive analysis, compared to LO theoretical predictions for string resonances, excited quarks, axigluons, colorons, scalar diquarks, S8 resonances, new SSM gauge bosons W′ and Z′, and RS gravitons. Middle: combined limits on gg/bb resonances for different values of f b . The theoretical cross section for an RS graviton is shown for comparison. Right: combined limits on qq/bb resonances for different values of f bb . The theoretical cross section for a Z′ is shown for comparison . Observed and expected 95% CL exclusions on the mass of various resonances. Observed 95% CL exclusions on the mass of Axigluon/Coloron and Color-Octet Scalar. Observed 95% CL lower limits on the minimum mass values of quantum black holes . 4 TeV
Transcript of Search for resonances and quantum black holes …2 Wide jets (R = 1.1) Highest Dijet Mass Event Mjj...
Search for resonances and quantum black holes using the dijet mass
spectrum in pp collisions at √s = 8 TeV Emine Gurpinar
On the behalf of CMS Collaboration
http://arxiv.org/abs/1501.04198
• Search for • Narrow dijet resonances decaying to quark-quark(qq), quark-gluon(qg), gluon-
gluon(gg) where the resonance width is negligible compared to the experimental dijet mass resolution,
• Narrow qq and gg resonances using the observed dijet resonance line shape of the RS graviton model for k/MPl = 0.1, which corresponds to a natural width equal to 1.5% of the resonance mass.
• Narrow resonances decaying to b quarks, • Wide dijet resonances that are not narrow compared to the detector resolution,
in qq and gg final states, • Wide qq and gg resonances using the dijet resonance line shape of the RS
graviton model with larger values of k/MPl, which corresponds to natural widths varying between 5% and 30% of the resonance mass.
• Quantum black holes decaying to two jets
• Several benchmark models of dijet resonances produced via the s channel
Wide jet algorithm: Require two leading AK5 PF jets to have pT>30 GeV and |η|<2.5, and to pass tight PF jet ID All other AK5 PF jets with pT>30 GeV, |η|<2.5, and passing loose PF jet ID added to the closest leading jet if within ΔR<Rwide=1.1 Wide jet algorithm developed to improve the dijet mass resolution for heavy resonances
§ Dijet system = two leading wide jets which satisfies |Δη|<1.3 and reconstructed in the region |η|<2.5 (suppresses QCD background)
l l Events with dijet mass (formed from the two wide jets) > 890 GeV because of
99.7% efficiency of L1 and HLT. l Applying the loose version of the combined secondary-vertex (CSV) algorithm to
the two leading jets to categorized as 0b, 1b, or 2b according to the algorithm output.
4 TeV 4 TeV
l There is no significant excess in data with respect to the background prediction l We proceed to set upper limits on the cross section of new resonances. l Bayesian formalism with a uniform prior is used for the cross section.
l The signal comes from our dijet resonance shapes l Background is fixed to the best
l The systematic uncertainties are included in the limit as nuisance parameters. These are:
l Jet energy Scale l Jet energy resolution l Background shape l Luminosity l b-tagging scale factors (applied only in the b-jet dedicated search)
l Fit the following parameterization to the data and compare to QCD prediction using the full CMS simulation and signal resonances. where m is the dijet mass, four free Four parameters P0, P1, P2, P3 and √s = 8 TeV . Inclusive dijet mass spectrum from wide jets (points) compared to a fit (solid line) and to predictions including detector simulation of multijet events and signal resonances. The predicted multijet shape has been normalized to the data. The vertical error bars are statistical only and the horizontal error bars are the bin widths. The bin-by-bin fit residuals normalized to the statistical uncertainty of the data, (data-fit)/σdata
, are shown.
Highest Dijet Mass Event Mjj = 5.15TeV
l Results of a search for dijet resonances and quantum black hole has been presented using inclusive and b-tagged dijet mass spectra.
l No evidence particle is found therefore we set upper limits at 95%CL on the product of the cross section, branching fraction into dijets, and acceptance.
l This results with 8 TeV full data set of pp collisions with CMS detector at LHC (19.7 fb-1) were approved (PAS EXO 2012-059) for
Moriond2013 conference; a paper has been produced and accepted by Phys. Rev. D. Reference: http://arxiv.org/abs/1501.04198
• Two set of samples: qq à G à qq, gg à G à gg, where G is the RS Graviton model implemented
in Pythia8 • The relative width of the resonance depend on the k/MPl parameter of the RS
Graviton model • The width-to-mass ratio of the resonance is Γ/M ≈ 1.4 × (k/MPl)2. • The range of relative widths for the resonances are (Γ/M) of 0.001%, 1.5%
(narrow resonance), 5%, 10%, 15%, 20%, 25%, 30%.
• The limits are quoted in a range of masses and widths that satisfies two conditions:
• at low mass, the core of the signal shape is preserved after the trigger selection mjj > 890 GeV,
• at high mass, the low-mass tails in the signal shape due to PDFs do not contribute significantly to the limit value (i.e. removing the low-mass tails, by truncating the signal shape at 85% of the nominal resonance mass, changes the expected limit by maximally 30%, corresponding to the typical uncertainty on the expected limits).
• The inclusive dijet search is also sensitive to quantum black holes primarily decaying to pair of jets, can be interpreted in terms of QBH production in models with large (n ≥ 2) or warped (n = 1) dimensions, where n is the number of extra dimensions.
• The peak position is related to the minimum mass of QBHs, Mmin QBH. • The low-mass dijet tails are due to detector resolution effects. • The shape is almost independent of the number of extra dimensions n and the fundamental Planck
scale MD. • The cross section limits are presented only for Mmin QBH ≥ MD, for different values of MD.
Dijet mass (GeV)1000 1500 2000 2500 3000 3500 4000 4500 5000 5500
(pb/
GeV
)jj
/dm
σd
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10
Data
Fit
QCD MC
JES uncertainty
CMS
Wide jets (R = 1.1)
| < 1.3jjη∆| < 2.5 & | η|
(8 TeV) -119.7 fb
q* (3.6 TeV)
W' (1.9 TeV)
Dijet mass (GeV)1000 2000 3000 4000 5000
1000 2000 3000 4000 5000
Res
idua
ls
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Dijet mass (GeV)1000150020002500300035004000450050005500
(pb/
GeV
)jj
/dm
σd
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10 / ndf 2χ
21.56 / 35Prob 0.9635
p0 4.741e-08± 7.112e-06
p1 0.02018± 6.999 p2 0.003194± 6.375
p3 0.001283± 0.2213
/ ndf 2χ
21.56 / 35Prob 0.9635
p0 4.741e-08± 7.112e-06
p1 0.02018± 6.999 p2 0.003194± 6.375
p3 0.001283± 0.2213
/ ndf 2χ
21.56 / 35Prob 0.9635
p0 4.741e-08± 7.112e-06
p1 0.02018± 6.999 p2 0.003194± 6.375
p3 0.001283± 0.2213
DataFit
CMS (8 TeV) -119.7 fb
b* (1.8 TeV) Z' (2.2 TeV)
G (2.8 TeV)
Z' (3.2 TeV)
0 b tags
Wide jets (R = 1.1)
| < 1.3jjη∆| < 2.5 & | η|
Dijet mass (GeV)1000 2000 3000 4000 5000
Res
idua
ls
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0
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Dijet mass (GeV)1000150020002500300035004000450050005500
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GeV
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/dm
σd
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29.01 / 35Prob 0.7518
p0 1.685e-07± 1.507e-05
p1 0.03329± 7.925 p2 0.005373± 4.965
p3 0.002157± -0.06957
/ ndf 2χ
29.01 / 35Prob 0.7518
p0 1.685e-07± 1.507e-05
p1 0.03329± 7.925 p2 0.005373± 4.965
p3 0.002157± -0.06957
/ ndf 2χ
29.01 / 35Prob 0.7518
p0 1.685e-07± 1.507e-05
p1 0.03329± 7.925 p2 0.005373± 4.965
p3 0.002157± -0.06957
DataFit
CMS (8 TeV) -119.7 fb
b* (1.8 TeV) Z' (2.2 TeV)
G (2.8 TeV)
Z' (3.2 TeV)
1 b tag
Wide jets (R = 1.1)
| < 1.3jjη∆| < 2.5 & | η|
Dijet mass (GeV)1000 2000 3000 4000 5000
Res
idua
ls
-2
0
2Dijet mass (GeV)
1000150020002500300035004000450050005500
(pb/
GeV
)jj
/dm
σd
-810
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10 / ndf 2χ
24.32 / 35
Prob 0.912p0 4.954e-10± 1.375e-08
p1 0.1057± 2.466 p2 0.01738± 8.023
p3 0.006963± 0.4947
/ ndf 2χ
24.32 / 35
Prob 0.912p0 4.954e-10± 1.375e-08
p1 0.1057± 2.466 p2 0.01738± 8.023
p3 0.006963± 0.4947
/ ndf 2χ
24.32 / 35
Prob 0.912p0 4.954e-10± 1.375e-08
p1 0.1057± 2.466 p2 0.01738± 8.023
p3 0.006963± 0.4947
DataFit
CMS (8 TeV) -119.7 fb
b* (1.8 TeV) Z' (2.2 TeV)
G (2.8 TeV)
Z' (3.2 TeV)
2 b tags
Wide jets (R = 1.1)
| < 1.3jjη∆| < 2.5 & | η|
Dijet mass (GeV)1000 2000 3000 4000 5000
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Dijet mass (GeV)1000 2000 3000 4000 5000 6000
)
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(8 TeV)
qq→ RS graviton →qq
1 TeV
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1 TeV
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Dijet mass (GeV)1000 2000 3000 4000 5000 6000
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-310×
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/M=1.5%ΓM/M=10%ΓM
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gg→ RS graviton →gg
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qq resonance mass (GeV)1000 2000 3000 4000 5000
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A × B × σ
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100.001%1.5%5%10%15%20%25%30%
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/ MΓ
gg resonance mass (GeV)1000 2000 3000 4000 5000
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= 2 TeVminQBHM
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-110
1
10
210n=1n=2n=3n=4n=5n=6
95% CL upper limit
CMS
(8 TeV) -119.7 fb
= 3TeVDM
(GeV)minQBHM
5000 5200 5400 5600 5800 6000 6200 6400
(pb)
A × B × σ
-710
-610
-510
-410
-310
-210
-110n=1n=2n=3n=4n=5n=6
95% CL upper limit
CMS
(8 TeV) -119.7 fb
= 5TeVDM
BH Mass (GeV)6000 6100 6200 6300 6400 6500
(pb)
A × B ×C
ross
Sec
tion
-710
-610
-510
-410
-310
-210
-110
1
10
210
310 = 6TeV
Dn = 1, M
= 6TeVD
n = 2, M = 6TeV
Dn = 3, M
= 6TeVD
n = 4, M = 6TeV
Dn = 5, M
= 6TeVD
n = 6, M
Observed 95% CL Upper Limit
CMS = 8 TeVs -1L= 19.71 fb
S8 resonance mass (GeV)1000 1500 2000 2500 3000 3500 4000 4500
(pb)
A ×
B ×
σ
-310
-210
-110
1
95% CL upper limit
gluon-gluon
CMS
(8 TeV) -119.7 fb
S8
Axigluon/coloron mass (GeV)1000 1500 2000 2500 3000 3500 4000 4500
(pb)
A ×
B ×
σ
-310
-210
-110
1
95% CL upper limit
quark-quark
CMS
(8 TeV) -119.7 fb
Axigluon/coloron
qq resonance mass (GeV)1000 2000 3000 4000 5000
(pb)
A × B × σ
-510
-410
-310
-210
-110
1
10
210
310
410CMS
(8 TeV) -119.7 fb
95% CL upper limits
Observed
Expected
σ 1±
σ 2±
Axigluon/coloron
Scalar diquark
W' SSM
Z' SSM
qg resonance mass (GeV)1000 2000 3000 4000 5000
(pb)
A × B × σ
-510
-410
-310
-210
-110
1
10
210
310
410CMS
(8 TeV) -119.7 fb
95% CL upper limits
Observed
Expected
σ 1±
σ 2±
String
Excited quark
gg resonance mass (GeV)1000 2000 3000 4000 5000
(pb)
A × B × σ
-510
-410
-310
-210
-110
1
10
210
310
410CMS
(8 TeV) -119.7 fb
95% CL upper limits
Observed
Expected
σ 1±
σ 2±
S8
RS graviton mass (GeV)1200 1400 1600 1800 2000
(pb)
A × B × σ
-210
-110
1
1095% CL upper limits
Observed
Expected
σ 1±
σ 2±
CMS
(8 TeV) -119.7 fb
(k/M=0.1)RS graviton
Resonance mass (GeV)1000 2000 3000 4000
Tagg
ing
effic
ienc
y
00.10.20.30.40.50.60.70.80.9
1
0 tags1 tag2 tags
CMS
(8 TeV)
Simulation bb→G
Resonance mass (GeV)1000 2000 3000 4000
Tagg
ing
effic
ienc
y
00.10.20.30.40.50.60.70.80.9
1
0 tags1 tag2 tags
CMS
(8 TeV)
Simulation bg→b*
Resonance mass (GeV)1000 2000 3000 4000
Tagg
ing
effic
ienc
y
00.10.20.30.40.50.60.70.80.9
1
0 tags1 tag2 tags
CMS
(8 TeV)
Simulation
qq/gg (q=u,d,s)→G
Tagging efficiencies for 0, 1, and 2 b tags selections as a function of the resonance mass for bb, bg, and qq/gg (where q=u,d,s) decay modes. The hatched regions represent uncertainties in the tagging efficiencies due to the variation of the b-tag scale factors within their uncertainties.
The observed 95% CL upper limits on σ × B × A for resonances decaying into qq/qg/gg final state (points and solid lines) are compared to the expected limits (dot-dashed dark lines) and their variation at the 1σ and 2σ levels (shaded bands). Predicted cross sections of various narrow resonances are also shown. The signal shape for the RS model is obtained weighting the shapes for qq and gg final states according to LO calculations of the relative branching fractions.
Resonance mass (GeV)1000 2000 3000 4000 5000
(pb)
A × B × σ
-510
-410
-310
-210
-110
1
10
210
310
410CMS
(8 TeV) -119.7 fb
95% CL upper limits
gluon-gluon
quark-gluon
quark-quark
StringExcited quarkAxigluon/coloronScalar diquarkS8W' SSMZ' SSMRS graviton (k/M=0.1)
Resonance mass (GeV)1000 1500 2000 2500 3000 3500 4000
(pb)
A × B × σ
-410
-310
-210
-110
1
10
jj)→B(X bb)→B(X = bbf
gg/bb]→95% CL upper limits [X
= 0.1) bbRS graviton (f = 1.0bbf = 0.75bbf = 0.5bbf = 0.1bbf
0, 1, 2 b tags
Graph
CMS
(8 TeV) -119.7 fb
Resonance mass (GeV)1000 1500 2000 2500 3000 3500 4000
(pb)
A × B × σ
-410
-310
-210
-110
1
10
jj)→B(X bb)→B(X = bbf
qq/bb]→95% CL upper limits [X
= 0.2) bbZ' (f = 1.0bbf = 0.75bbf = 0.5bbf = 0.2bbf
0, 1, 2 b tags
Graph
CMS
(8 TeV) -119.7 fb
b* resonance mass (GeV)1000 1500 2000 2500 3000 3500 4000
(pb)
A × B × σ
-410
-310
-210
-110
1
10
95% CL upper limitsObservedExpected
σ 1 ±
σ 2 ±
b*
0, 1, 2 b tags
Graph
CMS
(8 TeV) -119.7 fb
• It is no longer appropriate to use the narrow resonance to set limits on Axigluons/Colorons and S8 since They are wide resonances.
• The width of the Axigluon/Coloron is Gamma=alphas_s*M, the S8
resonance is (5/6)*model is alpha_s(M). The width is between %5 and %10.
• We have experimental limits only for 5% and 10% resonance so
we perform a linear interpolation between 5% and 10% limits for each mass value.
• We built a new qq experimental limit curve for the axigluon/coloron
(such that at each mass value the limit correspond to a relative width equal to alpha_s(M)) and a new gg experimental limit curve for the S8 resonance (such that at each mass value the limit correspond to a relative width equal to 5/6*alpha_s(M))
Observed 95% CL upper limits on σ × B × A as a function of the minimum mass of quantum black holes, compared to theoretical predictions for a quantum gravity scale of MD = 2 TeV, MD = 3 TeV, MD = 4 TeV, and MD =5 TeV, with the number of extra dimensions n ranging from one to six.
Measured number of events in data
number of events from signal
Expected number of events from background
Dijet mass spectra (points) in different b-tag multiplicity bins compared to a fit (solid line). Predictions for RS graviton, Z’, and excited b-quark signal spectra are also shown. The vertical error bars are statistical only and the horizontal error bars are the bin widths. The bin-by-bin fit residuals normalized to the statistical uncertainty of the data, (data-fit)/σdata, are shown at the bottom of each plot.
Observed and expected 95% CL upper limits on σBA with systematic uncertainties included, for b∗ → bg resonances, compared with the LO theoretical cross section for excited b-quark production.
The observed 95% CL upper limits on σBA for narrow dijet resonances. Left: limit on gluon-gluon, quark-gluon, and quark-quark narrow resonances from the inclusive analysis, compared to LO theoretical predictions for string resonances, excited quarks, axigluons, colorons, scalar diquarks, S8 resonances, new SSM gauge bosons W′ and Z′, and RS gravitons. Middle: combined limits on gg/bb resonances for different values of fb. The theoretical cross section for an RS graviton is shown for comparison. Right: combined limits on qq/bb resonances for different values of fbb. The theoretical cross section for a Z′ is shown for comparison.
Observed and expected 95% CL exclusions on the mass of various resonances.
Observed 95% CL exclusions on the mass of Axigluon/Coloron and Color-Octet Scalar.
Observed 95% CL lower limits on the minimum mass values of quantum black holes.
4 TeV
![Theory of Andreev resonances in quantum dots · Andreev resonances in quantum dots 8761 derivation of the Breit-Wigner formula through a single resonant level [45]. This limit is](https://static.fdocuments.net/doc/165x107/6060572b65c18a52267c8885/theory-of-andreev-resonances-in-quantum-andreev-resonances-in-quantum-dots-8761.jpg)
