The h 1 a 1 a 1 4τ signature in the NMSSM at the LHC

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1 The h 1 a 1 a 1 4τ signature in the NMSSM at the LHC Stefano Moretti NExT Institute (Southampton & RAL) (in collaboration with Alexander Belyaev, Sami Lethi, Stefan Hesselbach Alexander Nikitenko & Claire Shepherd-Themistocleous) Paris Sud Seminar, Orsay, November 17, 2009 S. Moretti (NExT Institute) 1

2 NMSSM Higgs sector [e.g. Elliott, King, White, 93; Franke, Fraas, 95] [Ellwanger, Hugonie, 99; Miller, Nevzorov, Zerwas, 03; Barger, Langacker, Lee, Shaughnessy, 06] 2 doublets + 1 singlet 3 scalars h 1,h 2,h 3, 2 pseudoscalars a 1,a 2 and 2 charged Higgs H ± (3 3), (2 2) mass matrices for neutral Higgs 6 parameters (tree-level): λ, κ, A λ, A κ, tan β, µ eff = λ S where tanβ = v 2, v 1,2 H 1,2 v 1 Spectrum & decay calculator: NMSSMTools (NMSPEC & NMHDECAY) [Ellwanger, Gunion, Hugonie, 04; Ellwanger, Hugonie, 05, 06, 07, 08, 09; Domingo, Ellwanger, 07] Experimental constraints (LEP, Tevatron, B-physics, cosmo) as implemented therein S. Moretti (NExT Institute) 2

3 Difficult NMSSM scenario for the LHC [Ellwanger, Gunion, Hugonie, Moretti 03, 04; Miller, Moretti 04; Gunion, Szleper, 04] [Ellwanger, Gunion, Hugonie, 05; Moretti, Munir, 06; Moretti, Munir, Poulose, 06] [Chang, Fox, Weiner, 06; Arhrib, Cheung, Hou, Song, 06; Cheung, Song, Yan, 07] [Carena, Han, Huang, Wagner, 07; Forshaw, Gunion, Hodgkinson, Papaefstathiou, Pilkington, 07] [Heng, Oakes, Wang, Xiong, Yang, 08; Hodgkinson, 08; He, Tandean, Valencia, 08] [Domingo, Ellwanger, 08; Morrissey, Pierce, 08; Hodgkinson, Pilaftsis, 08; Gunion, 08] [Chang, Yang, 08; Cheung, Hou, 08; Domingo, Ellwanger, Fullana, Hugonie, Sanchis-Lozano, 08] [Lisanti, Wacker, 09] Singlet-like a 1 and/or h 1 can be light in large region of parameter space Large BR(h 1 a 1 a 1 ) or BR(h 2 h 1 h 1 ) Light a 1 (m a1 > 2m b ): previous attempt via VBF & 2b + 2τ? [ slides] Very light a 1 (m a1 < 2m b ) a 1 τ + τ possible [Dermisek, Gunion, 06, 07, 08] Usual Higgs@LHC search channels may fail: no-lose theorem violated [Ellwanger, Gunion, Hugonie 03] S. Moretti (NExT Institute) 3

4 No-lose theorem: "At least one Higgs boson should remain observable at the LHC whichever the model" The NMSSM can use MSSM channels. These are (with l = e,µ): 1) gg h/a γγ; 2) Wh/a or t th/a into γγl ± ; 3) t th/a with h/a b b; 4) b bh/a with h/a τ + τ ; 5) gg h ZZ ( ) 4 leptons; 6) gg h WW ( ) l + l ν ν; 7) WW h τ + τ ; 8) WW h WW ( ). S. Moretti (NExT Institute) 4

5 However, for the NMSSM case, violation could occur for a fraction of the parameter space where one of the following decay modes dominates: i) h h h, ii) h aa, iii) h h ± h, iv) h az, v) h h ± W ±, vi) a ha, vii) a hz, viii) a h ± W From preliminary studies, the following mode via VBF may be useful: [Ellwanger, Gunion, Hugonie and Moretti, 03, 04] qq qqw + W,qqZZ qqh 1,2 qqa 1 a 1 qqb bτ + τ jjbbl + l + p Ellwanger et al. used HERWIG with NMSSM patches (by SM), input from NMHDECAY (Ellwanger, Gunion, Hugonie) Detector effects from GETJET (F. Paige, MH Seymour): UA1,2 model PYTHIA + ATLFAST results quite different [Baffioni 03] S. Moretti (NExT Institute) 5

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11 Ellwanger, Gunion, Hugonie & Moretti, hep-ph/ S. Moretti (NExT Institute) 11

12 The selection in hep-ph/ left a large DY background from τ + τ + jet production. As a result, in hep-ph/ we substantially increased the severity of the selection designed to tag the forward and backward jets associated with the VBF process, by requiring the forward/backward hadronic activity to be reconstructed as actual jets. Also, we modified the constraints on the central ones. The final cuts were: η jet < 5, p T fwd/bwd > 25 GeV, pt central jets > 15 GeV, max(pt j 1, p T j 2 ) > 40 GeV, R jet jet > 0.4, M fwd bwd > 200 GeV, η fwd η bwd > 4, η fwd η bwd < 0, η lepton < 2.5, p T lepton > 10 GeV, no lepton isolation or b tagging, where the two forward(backward) jets, labelled as fwd(bwd), are defined as those with maximal(minimal) pseudorapidity and j 1,2 identify the two among the central ones that best reconstruct the a mass. S. Moretti (NExT Institute) 12

13 The h1 a1 a1 4τ signature in the NMSSM at the LHC S. Moretti (NExT Institute) 13

14 Recapping on jjbbl + l + p Differences from different detector performance and selection cuts Stephanie, Look up hep-ph/ This contains the results you should compare to. Those in hep-ph/03051 are obsolete, as the jet algorithm was different. We mean to update that paper, but there are few things left to be done before doing so. Anyhow, the difference in not very big, between th two. I can tell you that the overall efficiency out of the numbers in hep-ph/ is 8.5% for th signal and 4.2% for the tt background. Notice that we do not have lepton isolation cuts, as said in hep-ph/ You loose a facto of 5.3 for the signal there and of 2.1 for the background. If you remove lepton isolation, you overall efficiencies should go up to 6% and 10%, but you better verify this, because there are kinematic correlations among the cuts. Also recall that I use HERWIG+GETJET and you PYTHIA+ATLFAST (I reckon). GETJET is based on the detector and thus is quite different from ATLFAST, so I expect some discrepancies in efficienc between my and your data because of this. HERWIG and PYTHIA should be more consistent in compa Best, S. More simulations needed! S. Moretti (NExT Institute) 14

15 Here [Belyaev, Hesselbach, Lehti, Moretti, Nikitenko, Shepherd-Themistocleous, arxiv: ] (also in proceedings of Les Houches 2007) Scenarios with m a1 < 2m b BR(a 1 τ + τ ) 1 h 1 a 1 a 1 4τ mode at LHC for Higgs-strahlung (HS) pp h 1 V (V = Z,W ) Vector boson fusion (VBF) pp h 1 jj Analysis of signature 4τ 2µ + 2j + p Also in constrained NMSSM benchmark scenarios [Djouadi et al., 08] NMSSM parameter scan m a1 < 2m b scenarios, BRs, h 1 V V couplings S. Moretti (NExT Institute) 15

16 NMSSM parameter space with m a1 < 2m b and large BR(h 1 a 1 a 1 ) Wide scan with NMHDECAY M 1 /M 2 /M 3 = 150/300/1000 GeV, A t = A b = A τ = 2.5 TeV, M fl = M fr = 1 TeV 10 5 < λ, κ < 0.7, 1.5 < tan β < GeV < A κ < 100 GeV, 5 TeV < A λ < 5 TeV, 100 GeV < µ eff < 1000 GeV Points satisfying theoretical, LEP and B physics bounds: red: Ωh 2 > 0.11, black: Ωh 2 < 0.11, m a1 > 10 GeV, green: Ωh 2 < 0.11, m a1 < 10 GeV S. Moretti (NExT Institute) 16

17 Narrowed scan 20 GeV < A κ < 25 GeV, 2 TeV < A λ < 4 TeV, 100 GeV < µ eff < 300 GeV red: Ωh 2 > 0.11, black: Ωh 2 < 0.11, m a1 > 10 GeV, green: Ωh 2 < 0.11, m a1 < 10 GeV S. Moretti (NExT Institute) 17

18 Effective coupling R ZZh = ( g NMSSM ZZh 1 g SM ZZH ) 2 Points with m a1 < 10 GeV satisfying all contraints: black: R ZZh < 0.1, 0.1 < R ZZh < 0.5, R ZZh > 0.5 S. Moretti (NExT Institute) 18

19 Branching ratios of h 1 and a 1 BR(h 1 a 1 a 1 ) BR(a 1 τ + τ ) black: R ZZh < 0.1, 0.1 < R ZZh < 0.5, R ZZh > 0.5 S. Moretti (NExT Institute) 19

20 Correlations with LSP character y 2 15: singlino component of LSP black: R ZZh < 0.1, 0.1 < R ZZh < 0.5, R ZZh > 0.5 S. Moretti (NExT Institute) 20

21 Combination with selection efficiencies Simulation of h 1 2a 1 4τ 2µ + 2j + p with PYTHIA & HERWIG [Lehti, Nikitenko] For HS (pp h 1 W, W eν or µν), VBF (pp h 1 jj) MSSM with m A = m a1, m h = m h1 enforced Smearing effects, parton shower, hadronisation, heavy hadrons decay, underlying events Cuts HS: isolated µ (p > 19 GeV) or e (p > 26 GeV), η < 2.5; p µ > 7 GeV, ηµ < 2.1; p τ jet > 10 GeV, ητ jet < 2.1; isolated 1-prong τ s within R < 0.6 from µ; τ and µ oppositely charged; 2 τ + 2 µ pairs found VBF: 2 same sign µ with p > 7 GeV, η < 2.1, one track of p > 2 GeV within R < 0. 2 τ jet with p > 10 GeV, η < 2.1; 2 jets with p > 30 GeV, η < 4.5 (see next 5 slid grid of selection efficiencies for relevant m a1, m h1 Combination with BRs, R ZZh from NMSSM parameter scan S. Moretti (NExT Institute) 21

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27 Results HS VBF L int = 100 fb events/a 8000 events/a Largest cross sections for m h1 80 GeV, m a1 2m τ S. Moretti (NExT Institute) 27

28 Conclusions and outlook Final aim: no-lose or even more-to-gain theorem for NMSSM h 1 2a 1 4τ 2µ + 2j + p has significant potential However: only HS & VBF signal processes analysed Still lots of work needed... Proper NMSSM implementation in MC Backgrounds: irreducible, b b, t t, etc. Detector performance Finally, dismiss usual bias of heavy SUSY (SUSY backgrounds) S. Moretti (NExT Institute) 28