Transcript General Aspects of Higgs Portal Dark Matter

Topics in Higgs Portal Dark
Matter
Seungwon Baek (KIAS)
Yonsei, March 21, 2013
based on 1112.1847, 1209.4163
in collaboration with P. Ko, W.I. Park, E. Senaha
Outline
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Evidences for dark matter
Relic density
Direct detection
Indirect detection
Higgs portal singlet fermionic/vector DM
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Collider phenomenology (Higgs search)
EW precision tests
Vacuum stability
Perturbativity
• Conclusions
Dark Matter
• Ordinary matter
contribute only 4%
of the total energy of
the universe
• The bulk of the
universe is made up
of dark matter and
dark energy
Evidences for Dark Matter
• Rotation curve
• The observed stars
and galaxies move
faster than luminous
objects can support.
F. Zwicky (1933)
Evidences for Dark Matter
• The Bullet Cluster
• Two clusters of galaxies
moving away from each
other after collision.
Clowe, et. al. (2006)
• Red region
(visible)ordinary
matter (hot gas)
• Blue region
(invisible)more gravity
(dark matter)
• However, Lee & Komatsu
(2010) claims it is
incompatible with ΛCDM
model
Evidences for Dark Matter
• Cosmic Microwave
Background Radiation
(CMBR)
• CMBR is almost
perfect black body
radiation with
T=2.728K
• Isotropic with
anisotropy at the level
of 10^(-5)
• CMB power spectrum
shows
Dark Matter
• All the evidences for DM are via
gravitational interaction
• We do not know the nature of DM
• If DM is WIMP, it allows the particle
physics explanation, direct/indirect
detection, and its creation at LHC
WIMP miracle
Relic density
Bertone, et. al. 0404175
• Boltzmann eq.
• Introduce Y
• Conservation of entropy
• The Boltzmann eq. becomes
• Now introduce a variable x:
• For heavy WIMP, we can expand
• Then in terms of
• Now we can solve the Boltzmann eq.
• The current relic density
• The freeze-out temperature
WIMP DM Searches
Direct Detection
• The event # of WIMP-nucleon scattering
per unit time, per unit detector mass
Jungman, et.al. (1996)
scattering angle in the CM frame
The FF is a Fourier tranf. of the nucleus distribution function:
micrOmegas (2009)
Fermi distribution function
Effective operators for direct
detection
• v=10^(-3), q(max)=100MeV
• Cross section is calculated q=0 limit
• For SI (spin-independent) cross section
(Majorana DM)
Effective operators for direct
detection
• For Dirac DM
+: WIMP, -: anti-WIMP
• Scalar DM
• Vector DM
WIMP-quark scattering
Indirect Detection
• Proportional to DM annihilation rate
• Galactic center, Center of Sun(Earth) may
be good place to look for DM
annihilation signals.
• Observed flux
spectrum of photon (neutrino)
Evidences for Dark Matter
• Cosmic Ray Searches
• PAMELA satellite observed striking increase in
the positron spectrum
Indirect Detection
1203.1312, 1204.2797, 1303.1798
If confirmed, it may be a clear signal for 130 GeV DM.
Hidden Sector DM and Higgs Portal
• One possible WIMP DM scenario is the
framework of “Hidden Sector” DM
• DM may be singlet under the SM gauge
grouphidden
• Hidden sector is generic in SUSY or
superstring models
Hidden Sector DM and Higgs Portal
• The renormalizable Higgs can mediate
the interaction between the SM and
hidden sector
SM
HS(DM)
DM physics
• GIM-type cancellation occurs in the DM annihilation
and scattering cross section
0 for degenerate Higgs
Direct detection
• XENON100(2012)
Direct detection
• Exclusion plot by
XENON100
• gX: DM-X coupling
• Cancellation is quite
effective
DM relic density
• Thermal relic density
• Singlet Fermionic DM
• Vector DM
DM relic density
SFDM
P-wave annihilation
VDM
S-wave annihilation
Comparison with the EFT approach
• For heavy m2, H2 can be integrated out.
And EFT is a good approximation.
• S. Kanemura et.al 2010, A. Djouadi, et.al. 2011, O. Lebedev, H. M.
Lee, Y. Mambrini, 2011, L. Lopez-Hororez, Schwetz, Zupan 2012
Comparison with the EFT approach
• SFDM scenario is ruled out in the EFT
• We may lose information in DM pheno.
A. Djouadi, et.al. 2011
Comparison with the EFT approach
Comparison with the EFT approach
Higgs Phenomenology
• Higgs sector is extendedHiggs
phenomenology is different from the SM
one
SM
HS(DM)
Higgs Phenomenology
• Invisible decay of Higgs at tree is allowed
X
Hi
X
• Reduction of Higgs signal strength
Higgs Phenomenology
• Signal strength (reduction factor)
• ri<1. If some ri>1, our scenario is excluded
Atlas 2013
EW precision tests
• New contribution to the EW precision
obs. Barger, et.al. 2008
EW precision tests
• The S,T,U parameters give strong
constraints on the mixing angle α
EW precision tests
Higgs phenomenology
It will be difficult to produce the 2nd Higgs at the
LHC.
Higgs phenomenology
Direct detection
Direct detection
Vacuum stability (EW)
• Requiring the global min. of the Higgs
potential is at the EW vacuua constrains
the parameters of the Higgs portal
violates this condition
Triviality and vacuum stability bound on mH
125GeV
The Higgs potential may become unstable before
Mpl.
• Higgs portal model can provide negative
contribution to the SM-like Higgs.
• Lebedev 2012, J. Elias-Miro, et.al 2012
Conclusions
• DM with Higgs portal
– provides cancellation to reduce the direct
search bound
– improves the stability of Higgs potential
– changes the Higgs search at colliders
– is constrained by EWPT and the discovery of
SM-Higgs boson
• It will be difficult to produce the 2nd
Higgs.