1. Gauge-Higgs Dark Matter
山下　敏史　(名古屋大学)
２０１０年１月１３日　
余剰次元物理研究会＠大阪大学
based on arXiv: [hep-ph]
with N. Haba (Osaka Univ.)
S. Matsumoto (Toyama Univ.)
N. Okada (KEK --> Alabama Univ.)

2. Overview Motivation for beyond the SM DM in gauge-Higgs unification
hierarchy problem
dark matter
dark energy
inflation
・・・
SUSY
Technicolor
Extra dimension(s)
ADD (large XD)
RS (warped XD)
GHU (TeV XD)
DM in gauge-Higgs unification
New DM candidate in general XD
apply it to GHU

3. Plan
Overview
New DM candidate
Gauge-Higgs Dark Matter
Summary

4. New DM candidate What’s the DM? dark (NR) matter (quasi) stable
neutral, colorless
massive, ・・・
superweak coupling
axion, gravitino, ・・・
protecting symmetry
by hand
R-parity, T-parity, ・・・
accidental
KK-parity, ・・・

5. New DM candidate lightest AP mode as DM candidate applicable to S1/Z2
N.Haba, S.Matsumoto,
N.Okada and T.Y.
arXiv:
applicable
to S1/Z2
lightest AP mode as DM candidate
S1 compactification :
The Lagrangian should be periodic.
Fields need not single-valued.
e.g. anti-periodic (AP) B.C. can be imposed.
Terms w/ odd # of AP fields are AP, and forbidden.
AP fields must appear in pairs.
periodic : even
anti-periodic : odd
accidental Z2

6. gauge-Higgs dark matter
New DM candidate
N.Haba, S.Matsumoto,
N.Okada and T.Y.
arXiv:
lightest AP mode as DM candidate
Why should we introduce AP fields?
-- In general, no reason other than the DM.
-- In the gauge-Higgs unification scenario,
AP fermions are often introduced.
Because of the structure of GHU,
it has strong predictive power.
gauge-Higgs dark matter

7. Plan
Overview
New DM candidate
Gauge-Higgs Dark Matter
Summary

8. Gauge-Higgs Dark Matter
D.B. Fairlie　 (1979)
N.S. Manton　(1979)
Gauge-Higgs Unification
5D theory
gauge field
compactification
4D theory
gauge field
scalar field
with KK modes
Higgs
5D gauge invariance protects the Higgs mass!!
H.Hatanaka, T.Inami & C.S.Lim (1998)

9. Gauge-Higgs Dark Matter
warped GHU
easily realizes large mKK/mW, Yt and mh.
Cf.) flat GHU
The EW observables tend to get large corrections.
small VEV
(additional) AP fermions
Haba, Hosotani, Kawamura & T.Y. (‘04)
Agashe & Contino (2005)
DM?
Cf.)
M. Regis, M. Serone & P. Ullio (2003)
G. Panico, E. Ponton, J. Santiago & M. Serone (2005)
model, with an exchange (Z2) symmetry
B.C. :

10. Gauge-Higgs Dark Matter
our setup
N.Haba, S.Matsumoto, N.Okada and T.Y.
SO(4) SM
SO(4)
SO(5)
boundary Higgs
UV brane
IR brane
B.C.
EW Higgs

11. Gauge-Higgs Dark Matter
our setup
N.Haba, S.Matsumoto, N.Okada and T.Y.
SO(5) adjoint : SM
SO(4)
SO(5)
boundary Higgs
UV brane
IR brane
B.C.
EW Higgs

12. Gauge-Higgs Dark Matter
SM fermion sector
not simple but possible
We just assume realistic models are
somehow constructed.
( little effect in this calculation.)
Higgs effective potential is not calculable.
We treat and as free parameters
to parameterize the effective potential, model independently.
with
additional AP fermion as GHDM
parity odd bulk mass parameter c.

13. Gauge-Higgs Dark Matter
AP DM in warped GHU
relevant int. are those w/ Higgs and gauge.
Interactions with Higgs are largely controlled
by the gauge symmetry.
three parameters.
50 AP fermion (in SO(5) * U(1) model)
--> cross sections
--> Boltzmann Eq.
--> relic abundance

14. Gauge-Higgs Dark Matter
N.Haba, S.Matsumoto,
N.Okada and T.Y.
arXiv:
result ( , )
relic abundance
direct detection
CDMS2
mDM=mh/2
WMAP5 + BAO + SN

15. Summary A new candidate of DM in general XD models
Anti-periodic fields appear in always in pairs.
accidental Z2 symmetry!
Gauge-Higgs Dark Matter
In the GHU, AP fermions often introduced.
the lightest one may be the DM.
Predictive because of the structure of GHU.
consistent w/ WIMP scenario,
future DD experiments will completely cover
the interesting (bulk) region.