# Presentation: 672029

## Searches for Non-SM Higgs Bosons at the Tevatron

- Makoto Tomoto (Fermilab)
- On behalf of the DØ & CDF Collaborations

- Moriond QCD  March 16th, 2005

## Outline

- SUSY Higgs Bosons
-  Search for h(bb)bb (DØ)
-  Search for hX X (CDF)
- Long-Lived Doubly Charged Higgs Bosons (CDF)

## SUSY Higgs

- In two Higgs doublet model, such as MSSM
- 5 physical Higgs bosons   h, H, A, H+, H- (mh < mH)
- tan = vu/vd : ratio of vacuum expectation value of 2 Higgs
- Cross sections for bbh enhanced like tan2
- Tevatron is sensitive to large tan and mA > ~90 GeV
- h is predicted to be light (mh < ~135 GeV)
- LEP limit is mh> ~92 GeV @ 95 C.L.
- At high tan , A is almost degenerate with h/H
-  (A) ~ (h/H), (A) ~ (h/H)
- Br(Abb) ~ Br(h/Hbb) ~ 90%
- Another 10% is Br(A/h/H)
-  hbb(bbbb) and hXX are the best channels to search for h/H/A

##  h(bb)bb Search (DØ)

- Jet

**L****xy****/********(L****xy****) > 5**

- Secondary Vertex

- Primary vertex

- L=260pb-1
- Trigger :	 at least 3 jets with ET>15GeV
- Selection
- Offline selection on leading jets  optimized for each Higgs mass
- Secondary Vertex b-Tagging
- Double b-tag and Triple b-tag
- Backgrounds
- QCD fake: jjjj ... From Data
- QCD heavy flavor:
- 	bbjj, ccjj, cccc, bbcc, bbbb
- 	... From Data
- Other: Z(bb,cc), tt ... From MC
- Simulations
- SM Higgs ... PYTHIA
-   and kinematics adjusted to NLO
- 	(P.R.L 94, 031902(2005) Dawson et.al)
- Background
- PYTHIA,ALPGEN,MADGRAPH

##  h(bb)bb Search (DØ)

- “mis-tag” rate function from full samples (as a function of pT and )
- ~2%
- (double b-tag data) x (mis-tag rate) = (triple b-tag backgrounds)
- Shape of events with  3 b-jets similar to double b-tag distribution
- Their cross sections are very small
- Fitting triple b-tag dijet mass distribution outside the signal region

- Double b-tag

- Triple b-tag

- Full data x (mis-tag)2

- Heavy Flavor MC

-  x mis-tag

- signal

##  h(bb)bb Search (DØ)

- No evidence and Set Limits on cross section & tan vs. mA plane
- Set limits on tan  vs. mA in two of the “benchmark scenarios”
- “No mixing” and “maximal mixing” in the stop sector
- 	 max-mix : designed to maximize allowed parameter space
- Exclude significant portion of tan down to 50, depending on mA and MSSM scenario

**Two benchmark MSSM scenarios**

-   < 70-20 pb @ 95 % C.L for
-  mA = 90-150 GeV

- For mA = 120 GeV:
- 	 < 31 pb @ 95% C.L. , tan < 55 @ 95% C.L. (Max Mixing)

- No mixing

##  hXX (CDF)

- 200pb-1 sample collected by  triggers (e/ + isolated track)
-  e e/ + , h hadrons + 
- Selection
- lepton pT, Z mass window cut
- Isolation on the h
- Event Topology  using ET, pT(l), pT(h)
- HT = |pT(l)|+|pT(h)|+ET > 50 GeV
- ET, pT(l), pT(h) correlations

- 1,3-prong is used

-  m<1.8GeV

##  h (CDF)

- Limits on xBr extracted from likelihood fits of m(l,h,ET)
- Signal Acceptance
- PYTHIA + TAUOLA
- 115GeV < MA < 200 GeV
- Effi. ~ 0.8% (eh),
- 	        ~ 0.6% (h)

-   < 9.8 – 2.6 pb for
- mA = 125-200 GeV

## Doubly-Charged Higgs Boson

- Appeared in several extensions to the SM and can be relatively light
- Left-Right Symmetric Model
- Higgs Triplet
- Little Higgs Model
- If short lived:
- Invariant mass of like sign dilepton
- DØ (113pb-1) m(HL) > 118 GeV  95% C.L.
- CDF (240pb-1) m(HL) > 136 GeV 95% C.L.
- If long lived (c > 3m)
- Can be measured by two high ionization tracks
- DELPHI : m(H) > 99.6 GeV @95% C.L.

- Coupling depends on
- L/R Handedness

## Long-lived H++/H-- Search (CDF)

- Cross Section (pb)

- L~290pb-1 collected by muon trigger
- pT(track) > 20 GeV
- dE/dx from drift chamber
- dE/dx depends on (charge)2
- Signal modeled by quadrupling the dE/dx of cosmic muons (~4x15ns)
- No Evidence found
- Limits on cross section
-  < 39.7– 32.6 fb @ 95%C.L.
- 	for m(H)=90-160GeV
- Mass Limits
- 	 m(HL) > 133 GeV @ 95 C.L.
- 	 m(HR) > 109 GeV @ 95 C.L.
- 	 m(H)  > 146 GeV @ 95 C.L.

- 20GeV

- 35ns

## Summary

- CDF and DØ searched for several non-SM Higgs bosons based on data of L=200-300pb-1
-  h(hbb)bb from DØ
-  hXX from CDF
-  Long-lived double charged Higgs from CDF
- No evidence of excess found
- Start excluding significant portion of parameter space
- New channels and improved results will come
- Twice more luminosity available