Presentation is loading. Please wait.

Presentation is loading. Please wait.

Moriond EW 2013BSM Higgs Searches at the Tevatron 1 Beyond the SM scalar boson searches in TeVatron Elemér Nagy CPPM on behalf of the CDF and D0 Collaborations.

Similar presentations


Presentation on theme: "Moriond EW 2013BSM Higgs Searches at the Tevatron 1 Beyond the SM scalar boson searches in TeVatron Elemér Nagy CPPM on behalf of the CDF and D0 Collaborations."— Presentation transcript:

1 Moriond EW 2013BSM Higgs Searches at the Tevatron 1 Beyond the SM scalar boson searches in TeVatron Elemér Nagy CPPM on behalf of the CDF and D0 Collaborations

2 Moriond EW 2013BSM Higgs Searches at the Tevatron 2 Search for Higgs bosons assuming the existence of a 4 th generation of fermions Fermiophobic Higgs searches Search for Φ  bb in Minimal Supersymmetric extension of the SM Search for heavy Higgs cascade decays Content

3 Moriond EW 2013BSM Higgs Searches at the Tevatron 3 The Tevatron

4 Moriond EW 2013BSM Higgs Searches at the Tevatron 4 Hermetic LAr calorimeter Muon detector with large coverage in iron toroid Central tracking system with large lever arm Both detectors have similar structure with different particular advantages D0 detector

5 5 10-year long Run II ended on Sept. 30 th, 2011 Total integrated luminosity delivered in Run II: ~12 fb -1 (per experiment) provided ~10 fb -1 analyzable data (per experiment)

6 6 SM Higgs Production GGF VH VBF

7 7 SM Higgs Decays

8 8 Higgs boson searches in the extension of the SM to a 4 th generation of fermions Additional heavy quarks u 4, d 4 enhance ~9 times the GGF production and makes it overwhelmingly dominant change BR’s at low M H GGF t,u 4,d 4 Additional heavy leptons l 4,v 4 may change the BR’s at high M H depending on their masses (ex. m l4 =155 GeV, m v4 =100 GeV) Opens new sources of CP violation Allowed by precision EW data G.D.Kribs, T.Plehn, M.Spannowsky, T.M.P. Tait arXiv:0706.3718v1

9 9 Use event selection for SM H  WW/ZZ search (mass range extended to 300 GeV) Reoptimize signal - background separation using only GGF in signal Set limit on gg  H  WW ignoring VH and VBF in signal and in acceptance assuming SM Br(H  WW)/Br(H  ZZ) Excluded regions at the Tevatron (95% CL) Low mass scenario: m l4 = 100 GeV m v4 = 80 GeV m u4 = 450 Gev m d4 = 400 GeV 120 – 224 GeV (observed) 118 – 272 GeV (expected) High mass scenario: m l4 = m v4 = 1000 GeV m u4 = 450 Gev m d4 = 400 GeV 120 – 232 GeV (observed) 118 – 291 GeV (expected)

10 10 Fermiophobic Higgs searches GGF Assume Higgs couplings to fermions vanish, all other couplings as in SM Can arise in models with an extended Higgs sector like Two Higgs Doublet Model (2HDM) with parameters that make the lightest Higgs fermiophobic Dominant decay is H  WW H  γγ is largely enhanced and provides most of the search sensitivity for M H <120 GeV Only VH and VBF production modes are non-negligible

11 11 SM H  γγ and H  WW /ZZ searches are reinterpreted and combined taking into account only the VH and VFB production modes and BR’s either by separating them from the GGF process or by reoptimizing without the GGF signal Excluded regions at the Tevatron (95% CL) 100 < M Hf < 116 GeV (observed) 100 < M Hf < 132 GeV (expected)

12 12 At tree level the MSSM is fixed by 2 parameters: tanβ=v u /v d, M A other MSSM parameters (e.g. µ) enter through radiative corrections (Δ b ) M h has an upper bound (~135 GeV) For tanβ > 1 couplings to down-type fermions are enhanced: Br(Φ  bb) ~90% Associate production of Φ with b-quarks has manageable multijet background at large tanβ the production cross section is largely enhanced wrt SM σ MSSM (bbΦ)xBr(Φ  bb) ~ 2 σ SM (bbΦ) tan 2 β/(1+Δ b ) 2 with Δ b ~µ tanβ Search for Φ  bb in Minimal Supersymmetric extension of the SM 2 complex Higgs doublet  5 Higgs particles: h, H, A, H +, H - Φ

13 13 3b final state 4b final state The search goal is to find a peak in invariant mass distributions of b-jet pairs in events with multiple b-jets CDF D0 Luminosity: 2.6 fb -1 5.2 fb -1 Trigger: ≥2 jet with b-tag info ≥3 jets with b-tag info Offline: 3 jets pT > 20 GeV, |η| 20(25) GeV, |η|<2.5 b-tag: sec.vtx algo NN (lifetime+IP) Signal sample: 3 b-tagged jets 3 and 4 b-tagged jet 11,5 K events 15 and 11 K events Signal simulation: PYTHIA events weighted by MCFM

14 14 Di-jet mass background template shapes for different flavour composition are determined from 2 b-tagged data events Signal is estimated from simultaneous fit of normalization of the signal and background templates to the 3 b-tagged data sample using an additional flavour separator Multijet background is simulated with Alpgen+Pythia and its flavour composition is determined from fit to data Likelihood ratio discriminant is used to separate signal from background CDF D0

15 15 Combined Tevatron cross section limit Combined Tevatron MSSM limit No width for Φ is assumed No radiative corrections applied 2 σ excess at 120 and 140 GeV after applying trial factors Finite width of Φ is taken into account Radiative corrections applied Model parameters chosen to maximize the theoretical upper bound on M h Phys. Rev. D 86, 091101(R) (2012)

16 Moriond EW 2013BSM Higgs Searches at the Tevatron 16 Search for heavy Higgs cascade decays CDF considers the hypothetical Higgs decay chain: H 0  H ± + W  (W + h 0 ) + W  W + (b b) + W motivated by a possible existence of strongly coupled electroweak symmetry breaking sector at the TeV scale in extended Higgs sectors like 2HDM Event selection is similar to the tt lepton+jets analyses: 1 charged lepton (e or µ) p T > 20 GeV, |η| < 1.1 ≥ 4 jets E T >15 GeV - at least 1 jet b-tagged Missing transverse momentum (MET) ≥ 20 GeV Signal is generated by Madgraph+PYTHIA fixing M h0 =126 GeV Background: tt and W(Z)+jet simulated by ALPGEN+PYTHIA multijet (instrumental) from low MET data control sample

17 Moriond EW 2013BSM Higgs Searches at the Tevatron 17 Events are reconstructed with M jj ~ M W Signal is serched for in M bb M H± + M W = M H0 Cross section limits have been derived ranging from 1300 down to 15 fb consistent with b-only expectation They do exceed the theoretical prediction therefore no region is excluded in the M H± vs M H0 parameter space More details in arXiv:1212.3837 M M

18 Moriond EW 2013BSM Higgs Searches at the Tevatron 18 Summary More details can be obtained from the CDF and D0 web pages http://www-cdf.fnal.gov/physics/new/hdg/Results.html http://www-d0.fnal.gov/Run2Physics/WWW/results/higgs.htm Higgs boson searches beyond the SM at the Tevatron were presented - assuming the existence of 4 th generation fermions (CDF+D0 ≤10 fb -1 ) - fermiophobic Higgs bosons (CDF+D0 ≤10 fb -1 ), - SUSY Higgs in 3 and 4 b-quark final state (CDF+D0 ≤ 5.2 fb -1 ) - first study of multiple Higgs bosons in cascade decays (CDF ≤ 8.7 fb -1 ) No evidence for a BSM signal has been found We excluded - 120 < M H < 224 GeV for the mass of the Higgs boson if 4 th generation fermions would exist, - 100 < M Hf < 116 GeV for the mass of a fermiophobic Higgs boson, - a domain in the tanβ vs M A MSSM parameter space We established upper limits on the the production cross section of heavy Higgs bosons in a specific two-doublet model

19 Moriond EW 2013BSM Higgs Searches at the Tevatron 19 Backup slides

20 Moriond EW 2013BSM Higgs Searches at the Tevatron 20 G.D.Kribs, T.Plehn, M.Spannowsky, T.M.P. Tait arXiv:0706.3718v1

21 Moriond EW 2013BSM Higgs Searches at the Tevatron 21

22 Moriond EW 2013BSM Higgs Searches at the Tevatron 22 Tevatron combination of the Φ  ττ search M t /M b

23 Moriond EW 2013BSM Higgs Searches at the Tevatron 23

24 Moriond EW 2013BSM Higgs Searches at the Tevatron 24 M bb in bkg enriched region


Download ppt "Moriond EW 2013BSM Higgs Searches at the Tevatron 1 Beyond the SM scalar boson searches in TeVatron Elemér Nagy CPPM on behalf of the CDF and D0 Collaborations."

Similar presentations


Ads by Google