Fermiophobic Higgs. Theoretical Outlook

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Fermiophobic Higgs. Theoretical
Outlook

• Many of SM extensions
  predict enhanced
  rate
  for Higgs decay into photon pairs
  due to suppressed couplings to
• - light quarks,
• - heavy quarks (TopColor)
• - up-type fermions (MSSMsmth)
  - all fermions
• Enhanced gg rate is also predicted by some
  models that employ Extra Dimensions
  as well as other Exotic models.

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Fermiophobic Higgs. Experimental
Outlook

• From Experimental Point of View
  it is convenient to consider gg decays
  of the Higgs in two extreme
  cases
• 1. all fermion couplings are zero
  (Fermiophobic Higgs)
• 2. Top Quark coupling is allowed
  (Topcolor Higgs)

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Enhancement of h?gg decays
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Why Look for Fermiophobic Higgs at Fermilab ?

• Tevatron performance offers search
  possibilities beyond current mass limits
  within next few years
• In comparison with LEP there is additional
  possibility of Higgs production via gluon fusion
  
  ? also TopColor Higgs can be
  looked for
• D0 is working on WW and gg channels
• Both analyses rely mostly on the calorimeter
  (most understood of all D0
  sub-detectors)
• Comparative Advantages
  
  WW is predicted to have higher
  Branching ratio gg is a clean signature, has
  smaller backgrounds

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Cross-Sections of Signal Production. Final States
Production Processes
gluon fusion, W/Z
associated, W/Z fusion
t

• ? Major final states are - gg
  - gg1 or more
  jets

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Background Cross Sections
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Previous Results
RunI (0.1 fb-1)
D0 gg2 jets analysis
found 4 events (expected background 6.0
/-2.1 ) set mass limit of 78.5 GeV at
95 C.L.
CDF gg2 jets gge, ?, MissingEt analysis

found 6 events (expected background 6.2 /-2.1
) set mass limit of 82 GeV at 95 C.L.
LEP limit 108.2 GeV at 95 CL
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Tevatron RunII Sensitivities (gluon fusion not
included)

• G.Landsberg and K.Matchev(hep-ex/0001007)
  estimated Tevatron RunII limits on h?gg Branching
  Ratio as a function of Higgs Mass with 95CL

Preliminary LEP exclusion contour,
A Andre Sopczak(hep-ph/0112082)
Fermiophobic h
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Tevatron RunII Sensitivities (gluon fusion
included)

MSSMsmth h
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Something about Photon ID specifics?
Not sure what to put for this
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Selection
of gg Candidate Events

• Trigger diEM or Single EM
  high Pt triggers
• Kinematic cuts Pt gt20GeV
• Acceptance cuts Central Calorimeter
  (CC) (?lt1.1) or EndCap Calorimeter
  (EC) (1.5lt?lt2.4),
  away (?0.015)
  from ?-cracks in CC
• Photon ID -0.05ltIsolationlt0.1,
  0.95ltEmfractionlt1.05, shower shape consistent
  with EM shape
  (8x8 Hmatrix ?2 lt75),
  total Pt (within ??lt0.1) of
  tracks lt1.46 GeV

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Monte Carlo Estimate of h?ggX Efficiencies
Included ID (without ?2 cut ),
Acceptance NOT included Kinematic cuts
W/Z associated W/Z fusion gluon fusion
M100 60.5 /- 0.7 62.6 /- 0.7 60.6 /- 0.7
120 63.0 /- 0.7 64.6 /- 0.7 62.4 /- 0.7
150 64.0 /- 0.7 66.3 /- 0.7 64.0 /- 0.7
200 62.5 /- 0.7 67.3 /- 0.7 66.0 /- 0.7
250 58.5 /- 0.7 67.2 /- 0.7 64.8 /- 0.7
300 52.0 /- 0.7 68.3 /- 0.7
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Signal and Background Monte Carlo Distributions
(Some or all of these (if any) as they are or
remade for double-checking their validity)
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di-EM Invariant Mass from 11/01-04/02 D0 data
Aslo need to calculate other QCD backgrounds,
(and Z?)
Isolated ?? Candidate Events
tight and loose cuts (calorimeter info only)
tracking info
estimated background contribution from direct ??
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Other plots ?
In case there are any suggestions
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Event Display of gg Candidate (or ggjet) ?

• Do you think it is worth to pick a most
  h-gtgamma gamma
  looking event out of the mass distribution two
  slides ago and show various event displays of it?

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Conclusions