Explicit CP violation in Higgs @ gg Colliders

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Explicit CP violation in Higgs _at_ gg Colliders

• Mayda M. Velasco
• Northwestern University

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Motivation

• MSSM CP violation in Higgs gives possible source
  of Cosmological Baryogenesis
• MSSM In addition to phases in the CKM, 2 extra
  phases in the gaugino mass and trilinear
  coupling
• Now we have MASS and CP Eigenstates

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Today Only focus on h1 (mass lt 135 GeV)

• Masses and decay width for h1,h2 h3 obtained
  from
• CPSuperH (CPsH)
• hep-ph/0307377
• FeynHigg
• hep-ph/0212037
• Work expanded by Sven Heinemeyer
• Note For some parameters
• h2,3? h1h1 and (mh1 lt 100 GeV)
• ? Visible at gg already discussed by Jack Gunion
  in the context of the NMSSM so I will not
  discussed it.

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Comparison of CPsH FeynHiggs (Matthew Hood)

• CPsH
• Leading order QCD correction (causes h?gg to be
  reduce by about 5)
• Special attention on the treatment of quark
  masses
• FeynHiggs
• Focus on mass evaluation and effective mixing
  angle
• All one loop calculations included in phases
  (causes higher mass)
• HDECAY
• Biggest effort for h?cc,bb (could affect large m
  and tanb)

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Comparison of SPS1aCPX in a minute ?
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All this calculation have theoretical
uncertainties!

• Independently of the theory we could isolate the
  CP-EVEN and CP-ODD by using linearly polarized
  gg-colliders
• Expected asymmetries in the MSSM are now being
  calculated by S. Heinemeyer using FeynHiggs.
  That is, he is calculating A3

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Recall from Jack Gunions paper
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All asymmetries isolated by manipulation
polarization
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For now lets just focus on Br measurements
based on circularly polarized beams

• Low energy gg collider can provide
• 2 for Gggbr(h?bb)
• 5 for Gggbr(h?WW)
• 8 for Gggbr(h?gg)

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CPX-Scenario
Tan b 5
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Tan b 20
Tan b 10
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gg
Tan b 5
LHC
Tan b 20
gg
gg
Tan b 10
LHC
LHC
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Conclusion

• Due to the significant changes in some of the
  couplings, like h?WW, in the presence of
  explicit CP violation
• gg?h?bb will really complement gg?h?gg
• CP violation in Higgs very important Additional
  effort is on going to get a prediction for the
  expected A1,2,3 asymmetries
• An asymmetry between linearly polarized gg
  collisions between the case where the
  polarizations are parallel vs perpendicular to
  each other is a clear indication of a CP
  admixture.
• Theoretically, this asymmetries are expected to
  be much less uncertain comparison between the
  CPsH and FeynHiggs predictions will be made.