Higgs Search Prospects with CMS LHC Physics Workshop

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Higgs Search Prospects with CMS LHC Physics Workshop Tata Institute of Fundamental Research 21

Higgs Search Prospects with CMS LHC Physics Workshop Tata Institute of Fundamental Research 21 - 27 October 2009 Andrey Korytov, UF Andrey Korytov, University of Florida, CMS LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

SM Higgs Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

SM Higgs Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Standard Model Higgs Trivia • Start from scalar field ○ • Require local gauge

Standard Model Higgs Trivia • Start from scalar field ○ • Require local gauge invariance ○ ○ • ○ ○ A min V(f) is not at f=0 non-zero vacuum expectation value v 0 expand around minimum effective mass terms for gauge bosons effective mass for h-field itself And even more: ○ force f interact with fermions with ad hoc couplings lf ○ • need massless gauge fields lagrangian acquires terms Mexican hat potential ○ • doublet pseudo-scalar in SM effective fermion masses (without a conflict with the Parity Violation) Higgs boson mass is the only free parameter Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Two important points • Higgs boson mass is the only free parameter • (Higgs-particle

Two important points • Higgs boson mass is the only free parameter • (Higgs-particle coupling) (mass of particle) ○ Production mechanisms: first one needs to produce heavy particles and then Higgs can emerge via its strong coupling to heavy particles ○ Decay channels: Higgs likes to decay to the heaviest particles it can decay to Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

1018 0 200 l l(Q) • If m. H<160 Ge. V at 1 Te.

1018 0 200 l l(Q) • If m. H<160 Ge. V at 1 Te. V, l runs down with Q, flips sign at some scale Q, and vacuum breaks loose • If m. H>160 Ge. V at 1 Te. V, l runs up with Q, explodes at some scale, theory becomes non-perturbative, and theorists can retire… ati v urb ert -p non 400 600 Higgs mass MH (Ge. V) Andrey Korytov, UF • e unstable vacuum 106 109 1012 1015 After renormalization 103 New Physics Energy Scale L (Ge. V) What we know: theory SM Higgs has a very narrow window of opportunity to be self-sufficient due to a fine-tuned accidental cancellation of large correction factors LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

What we know: direct search at LEP ee+ Tight Cuts The final word from

What we know: direct search at LEP ee+ Tight Cuts The final word from LEP: No discovery. . . Consistency with background: ~1. 7 s MH > 114. 4 Ge. V @95% CL Phys. Lett. B 565 (2003) 61 Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

What we know: direct search at Tevatron August 2009 March 5, 2009 CDF and

What we know: direct search at Tevatron August 2009 March 5, 2009 CDF and D 0 limits have been updated, but there weren’t a CDF+D 0 combination. VH, H bb H WW In lieu of the official combination this summer, here is my naïve guess: MH = 160 -170 Ge. V excluded @95% CL Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

What we know: circumstantial evidence LEP EWK Working Group H W EW precision measurements

What we know: circumstantial evidence LEP EWK Working Group H W EW precision measurements +35 Best Fit: m. H = 84 - 26 Ge. V Upper limit @ 95% CL: m. H 157 Ge. V Upper limit including direct search exclusion: m. H 186 Ge. V Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

What we know: putting all together Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai,

What we know: putting all together Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Tevatron prospects towards the end of 2010 Assumptions: • projected 1. 5 -factor improvement

Tevatron prospects towards the end of 2010 Assumptions: • projected 1. 5 -factor improvement in sensitivity beyond “sqrt(L)” • 10 fb-1 per experiment Conclusion: Optimistically, Higgs is expected to be excluded everywhere with m. H<185 Ge. V If the expected limit then will be where it is projected now to be and the Higgs is nevertheless not excluded, it means there is a “hint” of an excess. Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

SM Higgs: discovery signatures at L=30 fb-1 H bb H tt inclusive qq. H

SM Higgs: discovery signatures at L=30 fb-1 H bb H tt inclusive qq. H H gg H WW H ZZ YES YES YES VH tt. H Colored cells = { detailed studies available } YES = { 5 s in the appropriate range of masses at L=30 fb-1 } Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Three forerunners cover full mass range m<130: m=160 -180: everywhere else: Andrey Korytov, UF

Three forerunners cover full mass range m<130: m=160 -180: everywhere else: Andrey Korytov, UF inclusive H gg inclusive H WW 2 l 2 v inclusive H ZZ 4 l LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

H ZZ 4 l So-called golden channel Forerunner for discovery in wide range of

H ZZ 4 l So-called golden channel Forerunner for discovery in wide range of masses Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

SM Higgs: H ZZ 4 l Main backgrounds: • • H ZZ 4 m

SM Higgs: H ZZ 4 l Main backgrounds: • • H ZZ 4 m ZZ—irreducible Zbb, Z+jets, tt Analysis flow: • cuts: ○ ○ • control samples for ZZ background: ○ ○ • Z-peak (Z and ZZ production are very similar) - preferred sidebands (too low statistics when discovery become possible) data-driven methods to measure ○ ○ ○ • isolation, vertex, kinematics: ZZ is the dominant bkgd Higgs events form a m 4 l peak lepton reconstruction efficiency isolation cut efficiency per event vertex cut efficiency per event full treatment of systematic errors (small effect) Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009 CMS 2006

H ZZ 4 l: significance de-rating Background-only pseudo experiment Search for Higgs peak Search

H ZZ 4 l: significance de-rating Background-only pseudo experiment Search for Higgs peak Search in a broad range of parameter phase space m. H=115 -600 Ge. V Probability of finding a local excess somewhere is much higher than naïve statistical significance might imply: e. g. S=3 is almost meaningless A priori assumptions must be clearly defined — actual probability - - probability implied by local statistical significance Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Standard Model Higgs: H gg Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct

Standard Model Higgs: H gg Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Standard Model Higgs: H gg Backgrounds: • prompt gg • prompt g + jet(brem

Standard Model Higgs: H gg Backgrounds: • prompt gg • prompt g + jet(brem g, p 0 g) • dijet L=1 fb-1 Signal x 10 Analysis: • Cut-based ○ ○ ○ PT, h, isolation, Mgg events sorted by photon quality (EM shower profile quality) CMS EM Calorimeter: very narrow peak (0. 7 Ge. V for best categories) • Optimized (NN) ○ ○ loose cuts and sorting event-by-event kinematical Likelihood Ratio bkgd pdf from sidebands (at least something good from having large bkgd) signal pdf from MC • Systematic errors folded in Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Standard Model Higgs: H gg CMS Search for a narrow peak in a broad

Standard Model Higgs: H gg CMS Search for a narrow peak in a broad range of masses: èlook-elsewhere effect must be taken into account: again, we will lose about ~1 unit of significance Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Standard Model Higgs: H WW 2 l 2 n Andrey Korytov, UF LHC Physics

Standard Model Higgs: H WW 2 l 2 n Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Standard Model Higgs: H WW 2 l 2 n Backgrounds: • • WW—partially reducible

Standard Model Higgs: H WW 2 l 2 n Backgrounds: • • WW—partially reducible tt, W+jets, Z, … Exploit that Higgs’s Spin=0 Hence, eptons from H WW 2 l 2 v tend to go in the same direction Analysis: • cuts: ○ • counting experiment, ○ ○ • no peak e. g. , m. H=160 gives 67 events/fb-1, with expected 37 bkgd events Signal Region background from a control regions, e. g. ○ ○ • e/m kinematics, isolation, jet veto, MET signal: 12<mll<40 Ge. V, small fll control sample: mem>60 Ge. V, large fll Bkgd uncertainties are not negligible in this analysis (especially at low L) Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009 Control Sample

Standard Model Higgs: H WW 2 l 2 n Significance Exclusion Andrey Korytov, UF

Standard Model Higgs: H WW 2 l 2 n Significance Exclusion Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Difficult (impossible) channel: tt. H, H bb If higgs boson is light, can we

Difficult (impossible) channel: tt. H, H bb If higgs boson is light, can we see H bb? SM Higgs: tt. H, H bb ATLAS 30 fb-1 CMS: • careful study of systematic errors in the Physics TDR • syst error control at sub-percent level is needed: not feasible. . . Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

VBF channels qq. H jet f jet h qq. H, H WW -- is

VBF channels qq. H jet f jet h qq. H, H WW -- is it better than inclusive H WW 2 l 2 n? qq. H, H tt -- is it better than inclusive H gg? CMS and ATLAS do not seem to quite agree… Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

VBF signature uncertainties: signal Are there fewer central jets in VBF? Madgraph+Pythia VBF qq.

VBF signature uncertainties: signal Are there fewer central jets in VBF? Madgraph+Pythia VBF qq. ZZ production non-VBF qq. ZZ production no difference in # of central jets? ? ? vs no difference? Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009 Andre Sznajder • • Christoph Hackstein Central Jets in different MCs different MC disagree on frequency and rapidity distribution of central jets

Christoph Hackstein VBF signature uncertainties: backgrounds tt+jets is one of the main bkgd Different

Christoph Hackstein VBF signature uncertainties: backgrounds tt+jets is one of the main bkgd Different MCs disagree again: as selection cuts are applied, a factor of 2 differences come, go, and come back again Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Standard Model Higgs: Summary CMS 2006 NLO cross sections Systematic errors included ATLAS update

Standard Model Higgs: Summary CMS 2006 NLO cross sections Systematic errors included ATLAS update should become available this year CMS+ATLAS will need approximately half-luminosity in comparison to a single experiment There are three forerunner channels: WW, ZZ, gg All other possible channels are much more difficult 14 Te. V benchmark luminosities (CMS+ATLAS): • 0. 1 fb-1: • 0. 5 fb-1: • 5 fb-1: Andrey Korytov, UF exclusion limits will start carving into SM Higgs cross section discoveries become possible if MH~160 -170 Ge. V SM Higgs is discovered (or excluded) in full range LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

How do we project all this to lower sqrt(s)? 14 Te. V 10 Te.

How do we project all this to lower sqrt(s)? 14 Te. V 10 Te. V ? 7 Te. V ? Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

How much do we lose at lower sqrt(s)? Mass range of prime interest m.

How much do we lose at lower sqrt(s)? Mass range of prime interest m. H~100 -200 Ge. V 14 10 Te. V: we lose factor of 2 in the required luminosity 10 7 Te. V: another factor of 2 Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

MSSM Higgs Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

MSSM Higgs Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

MSSM Trivia (1): basics • One doublet of Higgs pseudo-scalar fields is replaced with

MSSM Trivia (1): basics • One doublet of Higgs pseudo-scalar fields is replaced with two ○ one couples to up-fermions and has vev=vu ○ the other to down-fermions and has vev=vd ○ • • which allows for cancellation of the higgsino triangular anomaly loops 2 x 4 -3=5 physical scalar fields/particles: h, H, A, H± properties ○ tree-level: fully defined by 2 free parameters m. A, tanb=vu/vd ○ ○ ○ loop corrections: not negligible and give dependence on other MSSM paramters CP-odd A - never couples to Z and W: - decays: bb, tt (and tt for small tanb) CP-even h and H - SM-like in vicinity of their mass limits vs m. A - large tanb … enhances coupling to “down” fermions: b/t become very important (production, decays) … suppresses coupling to Z and W ○ ○ ○ H± Higgs “strongly” couples to tb and tn all Higgses bosons are narrow (G<10 Ge. V) decays to non-SM particles are possible, if SUSY particles are lighter Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

MSSM Trivia (2): loop corrections Loop corrections give sensitivity to the rest of SUSY

MSSM Trivia (2): loop corrections Loop corrections give sensitivity to the rest of SUSY sector, i. e. affect Higgs masses and couplings Special benchmark points*: • max stop mixing (mh-max): ○ ○ ○ • no mixing: ○ ○ • opposite extreme to above mh < 116 Ge. V gluophobic h ○ ○ • maximizes mh mh < 133 Ge. V LEP results are least restrictive gg h production is suppressed (top+stop loop cancellation) mh < 119 Ge. V small aeff (mixing of Fu/Fd): ○ ○ h tt and bb BR’s are suppressed even for large tanb mh < 123 Ge. V * M. Carena, S. Heinemeyer, C. Wagner, G. Weiglein, Eur. Phys. J. C 26, 601(2003) Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

MSSM Trivia (3): h/H/A decay modes h Andrey Korytov, UF H LHC Physics Workshop,

MSSM Trivia (3): h/H/A decay modes h Andrey Korytov, UF H LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009 A

MSSM Trivia (4): h/H/A production at LHC h H A tanb=30 • small tanb

MSSM Trivia (4): h/H/A production at LHC h H A tanb=30 • small tanb comparable to SM (dotted line) • large tanb much larger than SM, bb. F is an important addition Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

What we know experimentally mh-max scenario makes LEP results least restrictive dotted line –

What we know experimentally mh-max scenario makes LEP results least restrictive dotted line – expected limit light green – 95% CL, dark green – 99% CL yellow – theoretically not accessible Andrey Korytov, UF h/H m > 91 Ge. V A m > 92 Ge. V H± m > 79 Ge. V LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Light h/H: SM-like signatures • SM-like at the min/max mass vs m. A •

Light h/H: SM-like signatures • SM-like at the min/max mass vs m. A • for smaller tanb: SM-like properties are lost slowly as one departs from min/max mass • for large tanb: SM-like properties are lost rapidly as one departs from min/max mass This implies: ○ ○ small m (<140 Ge. V or so), most promising channels would be gg and VBF tt/WW MSSM sensitivity methodology: for each point in the MSSM (m. A, tanb)-plane ○ calculate mh and m. H ○ calculate ratio of CSx. BR for MSSM-over-SM ○ take SM significance (gg, VBF tt) with the same m and rescale by CSx. BR ratios Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009 m~90 tanb~6

SM-like searches re-interpreted for MSSM Higgs (PTDR 2006) ar. Xiv: hep-ph/0202167 v 1 Carena,

SM-like searches re-interpreted for MSSM Higgs (PTDR 2006) ar. Xiv: hep-ph/0202167 v 1 Carena, Heinemeyer, Wagner, Weiglein • Using SM-like low mass signatures CMS will cover the entire (m. A, tanb)-plane • It may take some time, up to 60 fb-1 or so at 14 Te. V • VBF tt is important, but VBF cuts have large efficiency uncertainties Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Heavy H/A at large tanb • given the H/A mass degeneracy, sometimes they are

Heavy H/A at large tanb • given the H/A mass degeneracy, sometimes they are referred to as F • production: ○ large bb. H component however, b’s have low p. T (b-tag eff is low) • decays: ○ bb-decay mode (~90%) overwhelmed with QCD background ○ tt-decay mode (~10%) the best bet for observation ○ mm-decays (~0. 03%) allow for measuring tanb via H/A mass split Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Heavy H/A at large tanb: bb. F, F bb (90%) • Trigger: ○ ○

Heavy H/A at large tanb: bb. F, F bb (90%) • Trigger: ○ ○ L 1: Jet, Quad. Jets, HT HLT: b-tagged jet 60 fb-1 • Main background: QCD • Offline selection: ○ ○ mass-dependent 4 high ET jets (~0. 4 M, 30, 30), |h|<2. 4 3 jets with b-tag (among 4 highest ET jets) centrality of the 4 -jet system >0. 7 • Result (m=500, tanb=50): ○ ○ signal efficiency ~1% S/B ~ 4% systematics—difficult, hard to contemplate without data standalone discovery not possible, hope for 2 s confirmation once m is known Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009 2 s contours

Heavy H/A at large tanb: bb. F, F tt (10%) Sub-channels considered: tmte tmthad

Heavy H/A at large tanb: bb. F, F tt (10%) Sub-channels considered: tmte tmthad tethad tmte (10% x 2 x 0. 17 = 0. 5%) • Trigger: leptonic • Main backgrounds: tt+t. W, DY, QCD • Offline selection (mass-independent): ○ ○ ○ leptons: - isolation - impact parameter exactly one jet, b-tagged 0 jets (with b-tag) helps suppress DY =1 jet helps reduce tt collinear approximation cuts for mtt S/B ~ 1: 1 systematic errors ~ 12% jets, MET, b-tag eff, tt CS, each contributing 5 -7% Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Heavy H/A at large tanb: bb. F, F tt (10%) Sub-channels considered: tmte tmthad

Heavy H/A at large tanb: bb. F, F tt (10%) Sub-channels considered: tmte tmthad tethad tmthad (10% x 2 x 0. 17 x 0. 65 = 2%) • Trigger: muon • Main backgrounds: Zbb, DY, tt, QCD • Offline selection (mass-independent): ○ ○ ○ ○ muon and tau: - isolation - impact parameter m. T(l, MET)<60 helps reduce tt, t. W exactly one jet, b-tagged 0 jets (with b-tag) helps suppress DY =1 jet helps reduce tt collinear approximation cuts for mtt signal efficiency ~0. 2% S/B ~ 1: 1 systematic errors ~ 15% Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009 with/without syst

Heavy H/A at large tanb: bb. F, F tt (10%) Sub-channels considered: tmte tmthad

Heavy H/A at large tanb: bb. F, F tt (10%) Sub-channels considered: tmte tmthad tethad (10% x 2 x 0. 17 x 0. 65 = 2%) • Trigger: electron • Main backgrounds: Zbb, DY, tt, QCD • Offline selection (mass-independent) ○ very similar to tmthad ○ however, e efficiency is lower and purity is worse (hence, cuts are harder) tmthad Andrey Korytov, UF tethad LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009 tethad tmthad

Heavy H/A at large tanb: bb. F, F tt (10%) Sub-channels considered: tmte tmthad

Heavy H/A at large tanb: bb. F, F tt (10%) Sub-channels considered: tmte tmthad tethadthad (10% x 0. 65 = 4%) • Trigger: isolated tjet (one or double) • Main backgrounds: QCD, tt+t. W, Zbb, DY, W+jets • Offline selection (mass-dependent) ○ two thad ~ ET 1, ET 2 > 0. 2 M, 50 Ge. V ~ isolated ~ impact parameter for leading pion ○ exactly one jet, b-tagged 0 jets (with b-tag) helps suppress DY/QCD =1 jet helps reduce tt ○ ○ collinear approximation cuts for mtt signal efficiency ~0. 3% S/B ~ 1: 1 systematic errors ~ 10 -20% = statistical error from control sample (SS tt events) Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

h/H/A at large tanb: bb. F, F mm (0. 03%) Observation (recall: BR~0. 03%)

h/H/A at large tanb: bb. F, F mm (0. 03%) Observation (recall: BR~0. 03%) • three distinct regions ○ ○ ○ high m. A~m. H~mh m. A<m. H (mh~m. A) • Trigger: muons • Main background: DY, Zbb, tt • Offline selection: ○ ○ ○ 2 OS muons, isolated, p. T>20 MET>40, no jets with ET>45 (kills tt) b-tags considered: - hard b-tag: at least 1 jet with b-tag - soft b-tag: at least 2(1) tracks with large impact Fit: (NTOT-NS)*bkgd+NS*signal(m) Bkgd shape: from DY(ee) and tt(em), with correction for e/m efficiencies (tag-and-probe) Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Heavy H/A at large tanb: bb. F, F mm (0. 03%) Measurement of tanb

Heavy H/A at large tanb: bb. F, F mm (0. 03%) Measurement of tanb • from peak width, but be beware of A/H mass splitting • model-dependent (width, splitting) • errors: stat + 15% (syst from theory) Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Heavy A (low tanb) Production: • Lose a factor of 10 in cross section

Heavy A (low tanb) Production: • Lose a factor of 10 in cross section • no more bb. F to help with bkgd rejection Decays: • bb and tt are still present, albeit somewhat reduced • However, more decay possibilities open up: H hh, H WW and ZZ, A/H tt, A Zh H Andrey Korytov, UF H LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009 A

Heavy A (low tanb): A Zh (2 l)(2 b) m(bb) Main bkgds: • Zbb

Heavy A (low tanb): A Zh (2 l)(2 b) m(bb) Main bkgds: • Zbb and Z+jets • tt Z+jets tt Zbb signal Offline selection: • e+e- or m+m(isolated, p. T>30, 15) • m. Z cut (± 5 Ge. V) • p. T(ll)>30 • two b-tagged jets (ET>25, 20) • MET<60 Background control: • tt: invert MET, MET>120 • Zbb+Zjets: MET<40, m(llbb)>500 Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009 m(llbb)

Heavy H/A special case: A/H c 2 c 2 Tune SUSY parameters to allow

Heavy H/A special case: A/H c 2 c 2 Tune SUSY parameters to allow A/H c 2 c 2 30 fb-1 • A/H c 02 l+l- + MET • Looks like SM H ZZ, but: ○ ○ no resonances plus MET • SM bkgd is very small • non-A/H SUSY contributes a lot ○ ○ first pass of the analysis: SUSY “bkgd” is Signal, not background! once we established an excess (and secured Nobel Prize), how would we resolve the Higgs contribution from non-Higgs? Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Heavy H/A, large tanb summary Tevatron limits CMS 2006 LEP limits Andrey Korytov, UF

Heavy H/A, large tanb summary Tevatron limits CMS 2006 LEP limits Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

MSSM Trivia (5): Heavy H± (m>mtop) Production ○ ○ gg tb. H± gb t.

MSSM Trivia (5): Heavy H± (m>mtop) Production ○ ○ gg tb. H± gb t. H± Decay channels large tanb: ○ ○ H± tb (BR ~80%) H± tn (BR ~20%) small tanb: ○ ○ ○ H± tb (BR ~100%) H± Wh (BR ~few %) H± tn (BR ~0. 5%) Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Heavy H± , large tanb: H± tb (BR~80%) • (Production) x (Decay) Signature: ○

Heavy H± , large tanb: H± tb (BR~80%) • (Production) x (Decay) Signature: ○ pp tb. H± or t. H± tt b(b) W W bbb(b) lv jj bbb(b) • Trigger: leptonic • Backgrounds: tt+jets, t. W+jets (incl. b-jets) note: signal ~0. 1 -1 pb, tt ~ 840 pb • Offline selection: ○ ○ muon (isolated, pt>20) 5 jets (ET>25, 3 b-tagged) or 6 jets (ET>25, 4 b-tagged) • Jet association: maximum likelihood taking into account • Systematics: ~5% from data (rate of events with one b-tag less) x (b-tag eff) • Conclusion: with the current level of understanding, this channel would not be observable kimematics, b-tagging probabilities, W and t mass constraints Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Heavy H± : H± tn (BR~20%) • (Production) x (Decay) Signature: pp tb. H±

Heavy H± : H± tn (BR~20%) • (Production) x (Decay) Signature: pp tb. H± or t. H± t(b) tn jjb(b) tn • Trigger: tau • Backgrounds: tt+jets, t. W+jets (incl. b-jets) • Offline selection: ○ ○ ○ ○ Isolated lepton veto MET > 100 E(t-jet) > 100, tau ID Rt > 0. 8 (t polarization is different for H tn and W tn) b-tagged jet Top and H mass constraints … Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

MSSM Trivia (6): Light H± (m<mtop) D 0 limit ~15% • Production ○ ○

MSSM Trivia (6): Light H± (m<mtop) D 0 limit ~15% • Production ○ ○ top decays: t b. H± BR depends on mass and tanb • Prime decays ○ H± tn (BR~100% unless tanb <1) Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Light H± (m<mtop) • (Production) x (Decay) Signature pp tt H±b Wb tnb lnb

Light H± (m<mtop) • (Production) x (Decay) Signature pp tt H±b Wb tnb lnb t l bb nn • Trigger: leptonic • Backgrounds: tt, W+3 jets • Offline selection: ○ ○ ○ ○ m. H=140 tanb=20 Ns 510 Nb Andrey Korytov, UF lepton (isolated, pt>20) 3 jets (ET>40) 1 b-tag MET > 70 Tau ID (isolated, OS lwrt lepton) Lead track ptrk/Et >0. 8 Simple event counting (excess over SM tt sx. BR) m. H=150 tanb=20 254 1280 m. H=160 tanb=20 92 Model independent: discovery sensitivity for BR(t H+b)~5% (with syst errors included) LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

MSSM Higgs: H± summary Tevatron limits Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai,

MSSM Higgs: H± summary Tevatron limits Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

MSSM Higgs Summary MSSM Higgs or SM Higgs? ATLAS L=300 fb-1 SM-like h only:

MSSM Higgs Summary MSSM Higgs or SM Higgs? ATLAS L=300 fb-1 SM-like h only: • considerable area… • even at L=300 fb-1 More handles? • measure branching ratios… • decays to SUSY particles… • SUSY particle decays… Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

More Exotic Higgses Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

More Exotic Higgses Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

More exotic Higgses: fermiophobic • • If the Higgs responsible for EWK symmetry breaking

More exotic Higgses: fermiophobic • • If the Higgs responsible for EWK symmetry breaking has nothing to do with fermion masses … Technically, this can be done in two-doublet models, like MSSM, but without MSSM imposed constraints ○ • Production: ○ ○ • VH (associate) qq. H (vector-boson fusion) Decays: ○ ○ • h, H, A, H±, the lightest h can be easily decoupled from fermions WW, ZZ; and gg for m. H<160 (via WW loop), nearly 100% for low m. H SM limits from Tevatron/LEP do not apply: ○ ○ Low mass (LEP, Tevatron): production is VH, but decays considered are bb High mass (Tevatron): decays are WW, but production is gg (top loop) H • Specific fermiophobic Higgs search limits: m. H<110 Ge. V (LEP, Tevatron) • LHC: up to m. H~130, H gg yield is higher for fermiophobic than for SM Higgs Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

More exotic Higgses: double-charged • one can add a triplet of scalar fields, giving

More exotic Higgses: double-charged • one can add a triplet of scalar fields, giving rise to neutral, charged, and double-charged Higgses • allows for introducing neutrino masses (alternative to See-Saw) • decay modes: ○ ○ ○ tt, mm, ee mixed lepton flavors are possible, too – not yet explored! also, WW is possible for m. H>160 • leptonic decays are very clean Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Higgs at LHC in 2010? Assume 10 Te. V and 200 pb-1 Can we

Higgs at LHC in 2010? Assume 10 Te. V and 200 pb-1 Can we compete with Tevatron in the 2010 Run? Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Rule of thumb For CMS with 200 pb-1 to compete with Tevatron in 2010

Rule of thumb For CMS with 200 pb-1 to compete with Tevatron in 2010 (8 fb-1/exp), we need to gain a factor of 40 via either • • • larger cross sections better performance being smarter (? ) combination of all of the above (we basically always lose in acceptance) NB: with 8 fb-1/exp, Tevatron friends shoot for excluding a SM Higgs with 100<m. H<185 Ge. V Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Factor of 40 in x-sections? Very roughly, • for gg-induced processes, one can compete

Factor of 40 in x-sections? Very roughly, • for gg-induced processes, one can compete at minv>150 Ge. V factor of 40 Andrey Korytov, UF • for qqbar-induced processes, one can compete at minv>1 Te. V LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

SM-like Higgs Competitive analyses: • H WW: ○ ○ SM exclusion sensitivity around m.

SM-like Higgs Competitive analyses: • H WW: ○ ○ SM exclusion sensitivity around m. H~160 -170 (already excluded by Tevatron) m. H > 150, LHC 10: Tevatron x-section ratio > 40 and HWW exclusion sensitivity s/s. SM remains < 10 up to m. H~500 if there is a fourth generation of quarks of arbitrary high mass, gg H x-section becomes about 9 times larger, regardless of the 4 th generation quark masses) • H ZZ: ○ is actually behind HWW at such low luminosity, but not too far behind for m. H>200 (HWW and HZZ naturally have to be combined) • H gg: ○ LHC 10: Tevatron x-section ratio ~30 is not sufficient to compete with Tevatron, but: ~ irreducible bkgd gg scales slower with energy (qq luminosities) ~ mgg resolution is expected to be ~2 (ATLAS) and ~4 (CMS) times better Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

MSSM: F tt LHC 10 : Tevatron ratios signal cross sections m = 115

MSSM: F tt LHC 10 : Tevatron ratios signal cross sections m = 115 tanb=40 m = 160 tanb=40 26 43 bkgd cross sections (Z) 8 luminosities 0. 2 : 8 S/sqrt(B) ~1. 5 ~2. 5 and bb. F: gg relative contributions are better at LHC 10 45% vs 35% 60% vs 40% Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

MSSM: Top ± H b LHC 10 : Tevatron ratios signal cross sections 400

MSSM: Top ± H b LHC 10 : Tevatron ratios signal cross sections 400 : 8 = 50 bkgd cross sections (tt) same as above luminosities 0. 2 : 8 S/sqrt(B) ~1 Relative role of non-ttbar backgrounds is smaller at LHC Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009

Summary Rule of thumb (for Higgs searches): • • 14 Te. V 10 Te.

Summary Rule of thumb (for Higgs searches): • • 14 Te. V 10 Te. V: we lose a factor of 2 in the required lumi 10 Te. V 7 Te. V: we lose another factor of 2 (important to remember this factor of 2 when we negotiate LHC operation in the post-2010 era) In 2010, CMS and ATLAS have a chance to enter the stage of Higgs searches (read competing with Tevatron), provided: • • • LHC delivers ~200 pb-1 at ~10 Te. V we take data with good efficiency we understand reasonably (not yet necessarily very well) our detectors/software and develop adequate data-driven techniques Good examples of competitive analyses: • SM H WW/ZZ for m>180 Ge. V • MSSM bb. F/F tt (m. A < 200, tanb~20) • MSSM light charged Higgs (m < mt) • Hgg: fermiophobic higgs m~110 Ge. V • H±±: can push limits to ~130 Ge. V And good luck to us all! Andrey Korytov, UF LHC Physics Workshop, TIFR, Mumbai, Oct 24 2009