Download Direct Search of Dark Matter in High

Direct Search of Dark Matter
in High-scale SUSY
Natsumi Nagata
Nagoya University
4 March, 2013
KEK-PH 2013
Based on J. Hisano, K. Ishiwata, N. Nagata, Phys. Rev. D87, 035020 (2013) .
SUSY SM
Supersymmetric (SUSY) Standard Model (SM)
scale
SUSY particles
TeV
EW
SM particles
SUSY SM
Supersymmetric (SUSY) Standard Model (SM)
scale
SUSY particles
TeV
EW
SM particles
Direct search
SUSY SM
Supersymmetric (SUSY) Standard Model (SM)
scale
TeV
EW
SUSY particles
126 GeV
Higgs boson
SM particles
Direct search
SUSY SM
Supersymmetric (SUSY) Standard Model (SM)
scale
High-scale SUSY ??
TeV
EW
SUSY particles
126 GeV
Higgs boson
SM particles
Direct search
Attractive features
High-scale SUSY scenario has a lot of fascinating aspects
from a phenomenological point of view.
 126 GeV Higgs boson can be achieved
(sufficient radiative corrections)
 SUSY CP/flavor problems are relaxed
(suppressed by sfermion masses)
 Gravitino problem is avoided
(heavy gravitino)
 Gauge coupling unification
(sfermions form SU(5) multiplets)
This scenario also accommodates the existence of
Dark Matter (DM) .
w/ light gauginos
(chiral symmetries)
Mass spectrum
On the assumption of a generic Kahler potential and no singlet field
in the SUSY breaking sector
(Loop suppressed)
Anomaly mediation
L. Randall and R. Sundrum (1998)
G.F. Giudice, M.A. Luty, H. Murayama, R. Rattazzi (1998)
Higgsinos can be light
(additional symmetries)
DM in the high-scale SUSY scenario
Assumption
The lightest SUSY particle (LSP) in this model is the main
component of the dark matter in the Universe.
Thermal relic abundance
• Wino (3 TeV)
• Higgsino (1 TeV)
scalar particles
gravitino (103 TeV)
We consider the direct detection of the DM
Precise calculation of
the DM-nucleon scattering
cross section
is required.
Diagrams Tree-level
``Higgs” contribution
They induce
Effective coupling
The couplings of DM
with “nucleon mass”
(Zij: Neutralino mixing matrix)
Diagrams 1-loop
``Scalar”
``twist-2”
Twist-2 operator
They induce
The couplings of DM
with “quark momentum”
These interactions are not suppressed even if the DM
mass is much larger than the W/Z boson mass.
J. Hisano, S. Matsumoto, M. Nojiri, O. Saito, Phys. Rev. D 71 (2005) 015007.
Diagrams 2-loop
``Gluon” contribution
Mass fractions for proton
The gluon contribution turns out to be comparable to the
quark contribution even if the DM-gluon interaction is induced
by higher loop diagrams.
It originates from the large gluon contribution to the nucleon mass.
J. Hisano, K. Ishiwata, and N. Nagata, Phys. Lett. B 690 (2010) 311.
Wino-like DM Effective coupling with a proton
tanβ = 1, 2, 5, 50
(from top to bottom)
tanβ = 1, 2, 5, 50
(from bottom to top)
There is a cancellation among these contributions
Wino-like DM Scattering cross sections with a proton
•
Cancellations between tree- and loop-level
contributions occur at a certain value of μ
•
Loop contribution is dominant in a wide range of
parameter region
Wino-like DM Scattering cross sections with a proton
Tree-level contribution interferes constructively to
the loop contribution in the case of low tanβ
The cross sections are within a reach of future experiments
in a wide range of parameter regions
Results Higgsino-like DM
Summary
•
We evaluate the DM-nucleon elastic scattering cross
sections in the High-scale SUSY scenario.
•
Electroweak loop contribution is dominant in a wide
range of parameter region.
•
There is a cancellation between tree- and loop-level
contributions and it significantly reduces the scattering
cross sections.
•
The resultant cross sections might be within a reach of
future experiments.
Backup
Results Higgsino LSP
tanβ = 1, 2, 5, 50
(from top to bottom)
tanβ = 1, 2, 5, 50
(from bottom to top)
Results
Loop contributions only
The SI cross section is almost independent of the wino mass.
J. Hisano, K. Ishiwata, and N. Nagata, Phys. Lett. B 690 (2010) 311.
Nucleon matrix elements
•The mass fractions ( for the scalar-type quark operators)
•For the twist-2 operators
The second moments of the parton distribution functions (PDFs)
Trace anomaly of energy-momentum tensor in QCD
The matrix element of gluon field strength tensor can be evaluated by using
the trace anomaly of the energy-momentum tensor in QCD
The trace anomaly of the energy-momentum tensor in QCD (Nf=3)
Heavy quark contribution
Gluon contribution
M. A. Shifman, A. I. Vainshtein and V. I. Zakharov, Phys. Lett. B 78 (1978) 443.
SI coupling of Majorana DM with nucleon
The effective coupling of DM with nucleon is given as follows:
Suppressed by
The gluon contribution can be comparable to
the quark contribution even if the DM-gluon
interaction is induced by higher loop
diagrams.
Mass fractions for proton
Elastic scattering cross section
One can derive the SI cross section by using the SI effective
couplings as follows :
From now on, we just show the results for the SI cross
section of WIMP DM with a proton as a reference value.
Higgs mass
The 125 GeV Higgs boson mass is easily accounted.
125 GeV
Small tanβ is favored
mt= 173.2 ± 0.9 GeV
M. Ibe, T.T. Yanagida (2012).