Detection of Neutralino WIMP

Yeong Gyun Kim(Korea Univ.)

I. Evidence for Dark MatterII. Dark Matter CandidatesIII. Direct Detection of Neutralino WIMPIV. Indirect Detection : Neutrino TelescopesV. Conclusions

sB decay and

What is Dark Matter ?

: stuff that neither emits nor absorbs detectable EM radiation

: the existence can be inferred by its gravitational effects on visible celestial body

Motion of Galaxies in Clusters

Galactic Rotation Curves

Gravitational Lensing

Temperature fluctuation of CMBR ……

I. Evidence for Dark Matter

Observed the Coma cluster of galaxies in 1933:

Fritz Zwicky (1898-1974)

Motions of galaxies in clusters

Found the galaxies move too fast to be confined in the cluster by the gravitational attraction of visiblematter alone.

The central 1Mpc ofComa cluster in optical

Dark Matter in cluster

Galactic Rotation Curves

Vera Rubin (1928-)

In 1970s, they found ‘flat’ rotation curves.

Dark Matter in galaxy

Cosmic Microwave Background Anisotropies

,

,

.

Brayon

Matter

Totaletc

WMAP satellite

Matter/Energy density in the Universe

1.0Total

0.04Baryon

0.27Matter

Total Matter

Non-Baryonic Dark Matter

Dark Energy (Cosmological constant)

Matter Baryon

0.005Lumi

Baryonic Dark Matter

Baryon Lumi

Neutrinos

Axion

WIMPs (Weakly Interacting Massive Particles)

MACHOs (MAssive Compact Halo Objects)

Baryonic Dark Matter candidates

Non-Baryonic Dark Matter candidates

; Neutralinos, Kaluza-Klein states, …. Wimpzillas (superheavy DM)

….

; Jupiter, brown dwarfs, white dwarfs, neutron stars, black hole….

Hydrogen gas, Dusts….

II. Dark Matter Candidates (what is Dark Matter made of ?)

Relic density of WIMPs

Time evolution of the number density of WIMPs

H : Hubble constant

Av : thermally averaged annihilation cross section of WIMP

eqn

3T3/ 2( / 2 ) exp( / )m T m T

( )T m

( )T m

WIMP : Weakly Interacting Massive Particle

2 23 [( ) ( ) ]eqA

dnHn v n n

dt

: equilibrium number density

Freeze out atAn H

26 3 110Av cm s

2 (1)h O

2 27 3 1(3 10 / )Ah cm s v

If

Minimal Supersymmetric Standard Model (MSSM)

SM fields plus an extra Higgs doublet and their superpartners

SU(3) x SU(2) x U(1) gauge symmetry and Renormalizability

R-parity conservation (to avoid fast proton decay)

( B: baryon number, L: lepton number S: spin )

3( ) 2( 1) B L SR

= +1 for ordinary particles= -1 for their superpartners

Soft Supersymmetry Breaking

LSP is STABLE !

Neutralino mass matrix

In the basis

0 0 01 2( , , , )B W H H

1

2

0 cos sin sin sin

0 cos cos sin cos

cos sin cos cos 0

sin sin sin cos 0

Z W Z W

Z W Z W

Z W Z W

Z W Z W

M M M

M M M

M M

M M

1 2,M M : Bino, Wino mass parameters

: Higgsino mass parameter

tan

0 0 0 01 2 3 1 4 2i i i i iN B N W N H N H

: ratio of vev of the two neutral Higgs

Lightest Neutralino = LSP in many cases (WIMP !! )

Neutralino Annihilation channels

etc.

Overview of the allowed regions of mSUGRA parameter space by the Relic density of Neutralino WIMP

1. Bulk region: at low m0 and m1/2: t-channel slepton exchange

2. Stau co-annihil. region: at low m0 where: neutralino-stau coannihilation

m m

3. Focus point region: at large m0 where mu is small: a sigificant higgsino comp.

,WW ZZ

4. A-annihilation region: at large tan 2Am mwhere

A ff

(hep-ph/0106204, Battaglia et al.)

30.3 /local GeV cm

270 /v km s

5 2 110010local

GeVcm s

m

Local Dark Matter density

Maxwellian velocity distribution

Local Flux of Dark Matter

III. Direct detection of Neutralino WIMP

Principles of WIMP detection

• Elastic scattering of a WIMP on a nucleus inside a detector

310v c

• The recoil energy of a nucleus with mass2

22

(max) 2( )recoil x N

N

mE v m

m m

610 10recoil NE m keV For

• This recoil can be detected in some ways :

Electric charges released (ionization detector)

Flashes of light produced (scintillation detector)

Vibrations produced (phonon detector)

Nm

Experimental Results

(CDMS collab. astro-ph/0405033)

Low energy effective Lagrangian for neutralino-quark int.

scalar interaction

5 5( ) ( ) ( ) ( ) ....q qL f qq d q q

spin-dep. interaction

• The other terms are velocity-dependent contributions and can be neglected in the non-relativistic limit for the direct detection.

• The axial vector currents are proportional to spin operatorsin the non-relativistic limit.

2 2 232( 1)spin F rG m J J

1( )p p n na S a S

J

( , ),

, , 2q p n

p n qq u d s F

da

G

( , )p nq : the quark spin content of the nucleon

Spin-dependent Neutralino-Nucleus cross-section

2

2 2313 142

...8

qq

W

g Td N N

M

,p nS

where (J : the spin of the nucleus)

: the expectation values of the spin content of the nucleus: depends on the target nucleus

( ) 0.78,pu ( ) 0.48,p

d ( ) 0.15ps

, 0.011,0.491p nS for 73Ge

, 0.415, 0.047p nS for19F

Nr

N

m mm

m m

: reduced mass

224( )scalar r p nm Zf A Z f

, ( , ) ( , )

, , , ,,

2

27p n q qp n p n

Tq TGq u d s q c b tp n q q

f f ff f

m m m

Scalar Neutralino-Nucleus cross-section

2( )

12 11 13 142

cos 1Re ( tan )( cos sin )

4 cosH d

d WW H

g mf N N N N

m m

where

( ) 0.020,pTuf

A : the atomic weight, Z : the nuclear electric charge

( , ), , | | , ,p np n Tq qm f p n m qq p n ( , ) ( , )

, ,

1p n p nTG Tq

q u d s

f f

( ) 0.026,p

Tdf ( ) 0.118pTsf

( ) 0.014,nTuf

( ) 0.036,nTdf ( ) 0.118n

Tsf

• In most instances, p nf f

2 2 24scalar r pm A f

: the scalar (spin-independent) cross section scales with the atomic weight, in contrast to the spin-dependent cross section.

• The scalar interaction almost always dominates for nuclei with A > 30.

: For , either interaction can dominate, depending on the SUSY parameters.

: has predominantly spin-independent interactions.

19F

73Ge

scalar spinvs.

sB decays in MSSM

In the Standard Model

• the decay proceeds through Z penguin and W exchange box diagrams.

• the decay is helicity suppressed due to angular momentum conservation.

9( ) 3 10SM sB B

Current Experimental Limit (90% CL)

7exp ( ) 5.4 10sB B

73.8 10

(CDF)

(D0)

In the MSSM (Babu,Kolda 2000)

• Fermion mass eigenstates can be different from the Higgs interaction eigenstates.

• This generates Higgs-mediated FCNCs.

3tan

21/ Am

p vs. ( )sB B

Both observables increase as tan increases.

Smaller Higgs masses give larger observable values.

2tanp

6( ) tansB B

41/p Am

4( ) 1/s AB B m

Minimal Supergravity Model

Unification of the gauge couplings at GUT scale

Universal soft breaking parameters at GUT scale

m : universal scalar mass M : universal gaugino mass A : universal trilinear coupling

Radiative EW symmetry breaking2 2 2

2 21 22

tan1

2 tan 1Z

m mM

Free parameters ( m,M,A,tan ,sgn( ) )

These conditions imply that

1 2M M at EW

scale

2M at EW scale

31 2

1 2 3 GUT

MM M M

21 2 2

5tan 0.5

3 WM M M

2 0.8M M

(tan 10, 0)A

Bino-like

01

2 2 2 211.8 0.04

2 ZM M m

Heavy Am 2 2 2 21( ( ) )

2dA H Zm m EW M

mSUGRA model ( A=0 and m,M < 1TeV )

Higgs and sparticle mass and ( )B b s

bounds included.

2 0.095h •

• 20.095 0.13h

• 2 0.13h

(S.Baek, YGK, P.Ko 2004 )

mSUGRA model ( A=0 and m,M < 1 TeV )

Higgs and sparticle masses and ( )B b s

bounds included.

Required that Neutralino is LSP

tan 55

7( ) 3.8 10sB B •

(S.Baek, YGK, P.Ko 2004 )

Non-universal Higgs mass Model (NUHM)

Parameterize the non-universality in the Higgs sector at GUT scale

2 21(1 ),

dHm m 2 2

2(1 )uH

m m

The above modifications of mSUGRA boundary cond. lead to the change of and at EW scale. Am

2 2 21( )

2uH Zm EW M

2 2 2 2( ) ( ) 2d uA H Hm m EW m EW

2 2 21( )

2dH Zm EW M

tan 35, 0A mSUGRA NUHM 1 2( 1, 1)

tan 35, 0A mSUGRA NUHM 1 2( 1, 1)

Non-Universal Higgs Mass Model 1 2( 1, 1)

tan 35, 0A

Non-Universal Higgs Mass Model 1 2( 1, 1)

tan 35, 0A

7( ) 3.8 10sB B •

•

7( ) 3.8 10sB B •

Non-Universal Higgs Mass Model 1 2( 1, 1)

tan 50, 0A

Non-Universal Higgs Mass Model 1 2( 1, 1)

tan 50, 0A

7( ) 3.8 10sB B •

•

7( ) 3.8 10sB B •

A specific D-brane Model (D.G. Cerdeno et al. 2001)

the gauge groups of the standard model come from different sets of Dp branes.

In this model, scalar masses are not completely universal and gaugino mass unificaion is relaxed.

the string scale is around GeV rather than GUT scale.1210

Free parameters:3/ 2 1,2tan , , , ,sgn( )m

3/ 2 1 ,m TeV 0 2 , 1,21 1

A D-brane Modeltan 50

A D-brane Modeltan 50

7( ) 3.8 10sB B

7( ) 3.8 10sB B

See D.G.Cerdeno’s talk this afternoon

for more detailed analysis, including

Non-universal scalar and gaugino masses

IV. Indirect detection of Neutralino WIMP( Neutrino telescopes : SuperK, AMANDA, ANTARES, IceCube)

Neutralino WIMPs in the galactic halo can be captured by the SUN and Earth through Neutralino-nucleus scattering

The neutrino flux can be detected in neutrino telescopesvia conversion

The accumulated Neutralino WIMPs annihilate into SM particles,which ultimately yields energetic neutrino flux

Super-K : Super Kamiokande detector

50,000 ton water Cherenkov detector,located in the Kamioka-Mozumi mine in Japanwith 1000 m rock overburden.

Set upper limits on WIMP-induced upwardmuon flux from the Sun and Earth etc. (~10^3 / km^2 yr)

AMANDA : Antiartic Muon and Neutrino Detector Array

Uses 3 km thick ice layer at the geographical South Pole.

A deep under-ice Cherenkovneutrino telescope.

AMANDA-II detector is in operation with 677 PMTsat 19 strings since 2000.

AMADA-II will be integratedto IceCube.

ANTARES : Astronomy with a Neutrino Telescope and Abyss environmental RESearch

In construction of a 12-string detector inthe Mediterranean Sea at 2400 m depth

A deep underwater neutrino telescope.

The number of Neutralino WIMP in the Sun (or Earth)

2A

dNC C N

dt

: the capture rate of WIMPs onto the Sun (or Earth)C

AC: the total annihilation cross section times relative velocity per volume

The present annihilation rate (at =4.5 Gyr, age of solar system)

2 20

1 1tanh ( )

2 2A A AC N C CC t

0t

2 20

1

2 AC C t 0 1ACC t for

1

2C 0 1ACC t for

When accretion is efficient, the annihilation rate dependson the capture rate C, but not on the annihilation cross section.

The Capture rate C depends on the elastic scattering cross section of Neutralino with matter in the Sun (or Earth).

The capture rate for the Earth primarily depends on the spin-independent DM scattering cross section. (only a negligible fraction of the Earth’s mass is in nuclei with spin)

For the capture rate of the Sun, both spin-independent and spin-dependent DM scattering cross section can be important. (spin-dependent interaction with hydrogen nuclei)

The neutrino-induced muon flux strongly depends onNeutralino-nucleus scattering cross section.

Muon Flux vs. m

mSUGRA model ( A=0 and m,M < 1TeV )(S.Baek, YGK, P.Ko PRELIMINARY)

from the Sun from the Earth

tan 55

tan 35

tan 10

vs.

(S.Baek, YGK, P.Ko PRELIMINARY)

scalarp /(2 / )spin

p m GeV

vs.

(S.Baek, YGK, P.Ko PRELIMINARY)

( )sB B in Non-Universal Higgs Model

from the Sun from the Earth

Muon Flux vs. mNon-Universal Higgs Mass Model

from the Sun from the Earth

(S.Baek, YGK, P.Ko PRELIMINARY)

7( ) 3.8 10sB B

Muon Flux vs. mNon-Universal Higgs Mass Model

from the Sun from the Earth

(S.Baek, YGK, P.Ko PRELIMINARY)

7( ) 3.8 10sB B

Muon Flux vs. mA D-brane Model

tan 55

(S.Baek, YGK, P.Ko PRELIMINARY)

tan 50

from the Earthfrom the Sun

tan 50

V. Conclusions

We considered the direct detection and indirect detection of neutralino WIMPs in the galactic halo, including the current upper bound of in mSUGRA, Non-Universal Higgs mass and a D-brane model.

( )sB B

We have shown that current upper limit on the branching ratio puts strong constraint on the model parameter space which could lead to quite large spin-independent neutralino-proton scattering cross section and neutrino-induced muon flux from the Sun and Earth.

sB