# Presentation: 641632

## Non-SM Higgs Searches at the TeVatron

- Andy Hocker
- Fermi National Accelerator Laboratory
- for the CDF and D0 Collaborations
- ICHEP 2006

## What we’re looking for

- Minimal supersymmetric SM Higgs bosons
- The neutrals: h0, H0, A0 ( = 0)
- The charged: H±
- Doubly-charged Higgs bosons (H±±)
- Part of Higgs triplet (0, H±, H±±)
- Appear in L-R symmetric SM extensions
- Can be light (~100 GeV), decay leptonically
- Extremely low backgrounds
- Fermiophobic Higgs bosons (0)
- Can appear in  “Type III” 2HDM
- Fermion couplings suppressed, boson enhanced
- Distinct signature of  decays via W triangles
- ...but no new results here...

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## MSSM 0 at the TeVatron

- Large tan (favored by LEP2 data) enhances couplings to b-quarks, 
- Most of 0 BR covered by bb (~90%), 
- Production:

- Main modes are
- gg, bb0 (0bb hopeless, but not 0)
- Associated production with b’s (both decays observable)

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## Experimental toolkit

- Bottom-quark tagging
- Exploit long lifetime of B hadrons
- Requires precision tracking (Si microstrip detectors) with as much forward reach as possible

- Tau ID
- Hadronic decays
- Isolated, narrow jets
- Requires good tracking/EM calorimetry for charged/neutral pion reconstruction
- Leptonic decays
- Requires good EM cal, muon detector coverage
- Large samples of Z’s/jets used to study efficiencies/fake rates

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## CDF and D0 in Run II

**Some highlights**
- Si detectors (D0 just got some more!)
- Good central tracking
- Forward muon systems
- Trigger/DAQ
- CDF: forward calorimeter

**Data samples**
- Over 1 fb-1 in the can
- Det/acc resumed operations in June, running well
- Results here range from 200-350 pb-1

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## Searches for b0, bb0 (0bb)

- Start from large multijet trigger sample
- Require at least 3 jets w/ displaced secondary vertex
- Form invariant mass of two leading b-jets, look for ≈bump
- Shape and normalization of bgd determined from doubly-tagged data

- 260 pb-1

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## b0, bb0 results

- 95% CL upper limit on xsec vs. *m**A*
- Compare w/ predicted xsec for canonical MSSM benchmarks
- Exclusions placed in *m**A*, tan  plane

- 260 pb-1

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## Searches for 0

- Select ehad, had, and (at D0) e events
- Partially reconstruct Higgs via

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## 0 results (comb. w/ bb)

- Includes bbb(b) searches --- these are your “take-home” plots for the TeVatron

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## Just in from D0!

- New search for (b)b0(b)b
- Less signal + less background = competitive limit
- Will be fruitful to combine
- Updated search for (b)bbb
- 0.9 fb-1
- New NN b-tagger
- Still no signal, but ever-tighter limits
- Too new for a nice *m**A*-tan plot

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## Charged Higgs in top decays

- Normally, ttWbWb
- Well-def’d final states
- If H± light enough, can replace one or both W’s
- BR(t Hb) and H± decays depend on tan , *m**H* (at tree level)
- H± 
- H± cs
- H± t*b
- H± W0
- Alters mix of tt final states

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## Indirect search for tH±b

- Look at event yield in 4 tt final states:
- lljj
- ljj
- ljjbj
- ljjbb
- Find joint prob to observe *N*data given expected yield for given *m**H*, tan , etc.
- Determine exclusion areas in *m**H* vs. “X” plane

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## Charged Higgs Results

- Indirect search from 200 pb-1 of tt in four final states
*m**H*/tan  exclusions for “no-mix” benchmark
- Other benchmarks explored as well
- Radiative SUSY corrections included!

- New direct search for tHbb
- Look for anomalous production of ttlbj (almost pure tt)
- 4 expected from ttWbWb, 6 observed
- Limits on BR(t->Hb) assuming BR(H±) = 1

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## Searches for_x0010_H±±e, 

- Same-sign lhad has significant background
- H±± pair-produced, so require additional (loose) leptons
- Counting experiment
- < 1 SM event expected, zero observed

| CDF H++ Lower Mass Limit |  |  |  |
| --- | --- | --- | --- |
|  | e |  |  |
| e | 133 | --- | --- |
|  | 115 | 136 | --- |
|  | 114 | 112 | ?? |
| “stable” | 134 |  |  |

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## Conclusions

- The MSSM provides the TeVatron with a real shot at a Higgs discovery
- Light h0, decent xsec
- Decays to b, 
- Null results for 0 searches put the squeeze on the MSSM from the large tan  side

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## Backuppery

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## Evidence/discovery

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## Searches for_x0010_H±±ee, e, 

- Same-sign dilepton search in 3 sigma mass windows
- Low backgrounds (limit ee search to > 100 GeV)

- No candidates, lower limits from 89-136 GeV set

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## Searches for quasi-stable H±±

- H±± particles that do not decay in the detector
- Look like highly-ionizing “muons”
- Large dE/dx in tracking chamber
- Basically, zero background... and zero observed

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006

## Searches for fermiophobic h0 

- Look for peaks in diphoton mass distribtution

- Current results not competitive with LEP, but will be soon!

- A. Hocker, ICHEP '06, Moscow

- 28-JUL-2006