Higgs at the Tevatron

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Higgs at the Tevatron
SUSY

• The Interpretation of the Run II
• Higgs Search potential
• Within the MSSM

Stephen Mrenna UC Davis
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Why SUSY Higgses are Interesting

• There are more of them
• 3 Neutrals and 1 Charged
• One of them should be light (?130-150 GeV)
• Couples to W/Z/t with SM-like strength
• Self coupling ? related to gauge couplings
• Sensitive to Top Squark properties
• Couplings not just proportional to mass
• Depends on tan?, mixing, SUSY spectrum

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Promising Signatures at Tevatron

• Standard Model-like Higgs bosons
• SM-like couplings to W/Z Bosons
• W/ZH(??bb)
• Relies on top quark experience in Run I
• Greatly Enhanced Yukawa couplings
• Non-SM-like couplings to heavy flavor
• ?bb H(??bb)

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SM-like processes in the MSSM
hlight CP-even
Hheavy CP-even
ACP-odd
Spira
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non-Standard processes

• Z?hA, HA, HH- W?hH,HH
• Spin suppressed
• Phase space suppressed
• t?bH, gb ?tH-, etc.
• Most rate for MH?mt-mb
• sensitive to large tan? radiative corrections
• Light Stop or Sbottom Higgs
• Leads to other SUSY signatures

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SM-like Higgs non-standard BRs

• Yukawa coupling corrections
• Loop induced coupling between b and
  Hup?sin?/cos?
• ?b ? Gluino/Sbottom and Stop/Higgsino
• Either sign and O(1) (and tan?tan?)
• ? decays may be greatly enhanced if ghbb?0
• A coupling depends just on ?b
• Higgs mixing effects
• SM-like Higgs is interaction state Hup
• Decay rates to WW, gg,?c c, ?? scaled up
• Needs large tan? as in GMSB or some GUT models

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bb?(??bb)
Overlapping signals (within ?M)
?A ? tan2? A??bb, ?? complicated
by h/H ?b dependent
MA (GeV)
Signal?bbAhH ? 2A
low mass
high mass
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Charged Higgs more ?b
t?bH
?-500 GeV
?b?0
DØ indirectRunI
BR contours
tan ? bound moves lower
Carena, Garcia, Nierste, Wagner
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?bgt0
Region of greatest experimental sensitivity also
has greatest sensitivity to (arbitrarily heavy)
SUSY spectrum
?500 GeV
BR contours
tan ? bound moves higher
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MSSM parameter dependence

• Stress variation instead of specific models
• Minimal Mixing
• Smallest asymptotic MH for fixed MSUSY
• Maximal Mixing
• Largest asymptotic MH for fixed MSUSY
• Large A and ?
• Suppression of H(??bb)
• Mgluino sensitivity

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Minimal or No (Stop) Mixing

• Left-Right Stop mixing is tuned to 0
• At?/tan?
• Tuning occurs for each value of tan ?
• Maximal Mh115 GeV
• SUSY scale average Stop mass2(1 TeV)2
• Higgs masses varying throughout plane
• Coverage gap for MA maximum Mh
  

b?b b?b (CDF/DØ)
10 fb-1
15 fb-1
LEP2
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Maximal (Stop) Mixing

• Large Left-Right Stop mixing
• At?6 MSUSY
• Maximal Mh125 GeV
• More luminosity needed
• BR h(? b?b ) is decreasing for Mh near upper
  limit

30 fb-1
b?b b?b (CDF/DØ)
15 fb-1
20 fb-1
LEP2
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Complementary ?b Effects
h depends on ?b mixing H/A depends on ?b
At-?1.2 TeV Mgluino0.5 TeV
-At?1.2 TeV Mgluino0.5 TeV
?bgt0
?blt0
30 fb-1
30 fb-1
b?b b?b suppressed
h(? b?b) suppressed
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Specific High-Scale Models
Theory excluded

• SUGRA

Baer, Harris, Tata
30 fb-1
20 fb-1
20 fb-1
tan?35
tan?4
Expt. excluded
10 fb-1
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• GMSB

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The Dirt

• Constant K-factors do not entirely represent
  backgrounds
• Region of MAMh treated naively
• Signals added in quadrature
• Full NLO bbH calculation not done
• Nor is the background!
• No Box-like corrections to W/ZH
• Contained in diagrammatic calculation
• Effective Potential and Diagrammatic calculations
  can differ
• Actual systematic errors may vary
• Used Run I experience that Systematics
  Statistics

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CP Violation

• SUSY breaking parameters in the
  Stop/Sbottom/Gluino sector may be complex
• Mixing between 3 neutral states
• h, H, A ?H1, H2, H3 mixed CP states
• Upper bound on Higgs mass remains the same
• Higgs couplings to W/Z and fermions differ
• CPV study of Higgs sector necessary to test
  mechanism for EW Baryogenesis

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CPV at Tevatron

• Large tan? and sizeable phase(At)
• MH190 GeV, but rate is too small at LEP
• All other modes (H1H2, etc.) not kinematically
  allowed

Carena, Ellis, Pilaftsis, Wagner
H1 still has too feeble couplings to W/Z Can
observe H2 at the Tevatron with 15 fb-1
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Unfinished Business

• ? identification and triggering
• gg?H(???) at high PT
• (???) to cover H(? b?b) hole
• ?bb A(???)
• (??bb) vs g background
• Interesting measurement by itself (see C.Hill et
  al.)
• Finding overlapping signals
• More pressing when considering CPV

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H(???) in RunII?
If H(?b?b ) and/or H(? ??) is suppressed, then
BR(H???) can increase
Not a SUSY-loop effect
LEP2
Mrenna, Wells
Bosonic Higgs
See also Matchev, Landsberg
Hup
Dominant decays are Hup to WW, gg,?c c
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Summary

• Run II promises rich SUSY Higgs phenomenology
• Test of SUSY prediction for SM-like Higgs
• Higgs CPV would be consistent with EW
  Baryogenesis
• Potential of observing non-SM-like Higgses
• May observe heavy sparticle effects in ?b
• Correlated with Gluino/Sbottom or Stop signals
• Light sparticles could yield Additional Signal
• At the least, an important warm-up for LHC