Weihai, July 8-12

New Physics from the Sky

朱守华 , Shou-Hua Zhu

ITP, Peking University

In collaboration with Xiao-Jun Bi, Jia Liu, Peng-Fei Yin and Qiang Yuan

Weihai, July 8-12

Title is motivated by ‘Dream of Red Chamber’

Weihai, July 8-12

Based on:

• Jia Liu, Peng-fei Yin, Shou-hua Zhu , Phys. Rev. D 77, 115014 (2008), arXiv:0803.2164.

• Peng-fei Yin, Jia Liu, Qiang Yuan, Xiao-jun Bi and Shou-hua Zhu, arXiv:0806.3689.

Weihai, July 8-12

Contents

1. Motivation

2. Neutrino Signal from DM annihilation in the Sun

3. Neutrino Signal from DM annihilation in the Milky Way

Weihai, July 8-12

1. Motivation

Weihai, July 8-12

3 major ways to detect dark matter

1. Missing energy at collider-based modern detector

2. Recoil energy of nucleus due to the scattering with dark matter (direct method)

3. Stable particles (neutrino, photon, etc.) due to dark matter annihilation

(indirect method)

Weihai, July 8-12

Dark matter at colliders

• LHC & Tevatron: PP->Z(->leptons)h(->missing energy) Zhu, EPJC(2006)

Higgs boson related to dark matter? Zhu, CPL(2007)

PP-> H -> h(->bottom pair) h(->missing energy)

Li, Yin and Zhu, PRD(2007)

• BEPC: e+ e- -> gamma+ U(-> missing energy) Zhu, PRD(2007)

Weihai, July 8-12

Neutrinos from the DM annihilations

• High energy Neutrinos (MeV~TeV, depending on cold DM mass) can be produced by dark matter annihilations.

• Interactions of neutrino with matter in the standard model (see next figure)

Weihai, July 8-12

Weihai, July 8-12

Pros and Cons

• Disadvantages: It’s hard to be detected such neutrinos in this energy range and with low flux. Large area neutrino telescope is needed!

We can detect these neutrinos (actually ch

arged muon) by large volume Cerenkov detectors, such as Super-kamiokande, IceCube, ANTARES…

Weihai, July 8-12

• Advantages: neutrinos are hardly energy loss and trajectory deflection during the propagation. They may preserve the information of the nature and distribution of the DM, provided that the source is near (Sun and Milky Way).

Weihai, July 8-12

2. Neutrino Signals from Solar Neutralino Annihilations in AMSB m

odel Jia Liu, Peng-fei Yin, Shou-hua Zhu , Phys. Rev. D 77, 115014 (20

08), arXiv:0803.2164.

Weihai, July 8-12

How to estimate muon flux detected by IceCube?

We need to know:

• Neutrino from neutralino annihilation in the Sun

• Neutrino propagation from Sun to Earth

• Converting to muon and detected at IceCube

Weihai, July 8-12

Neutrino signal from Solar center

• Dark matter scatters off nucleus in the Sun• Trapped by gravity of the Sun• Annihilation rate equilibriums capture rate

10

20 1 23 6

270 / 1003.4 10 ( )( )( )

0.3 / 10

H Hlocal SD SI

local

km s GeVC s

GeV cm v pb m

Astrophys.J.321.338(1992)

Weihai, July 8-12

Neutrino signal from Solar center

• Scattering of nucleus and neutralino

• Spin-dependent(SD) interaction

• Mainly axial-vector interaction• Exchanging Z, squark• In our paper, SD is dominant• Experiments in 07

• Spin-independent (SI) interaction• Scalar interaction• Exchanging H,h,squark• Dominant in heavy nuclei• XENON10 for a 100GeV WIMP

84.5 10SIp pb

0.1 ~1SD pb pb

PRD48,5519(1993)PRD44,3021(1991)

PRL 100， 0213030805.2939v1

Weihai, July 8-12

Dark matter annihilation in Anomaly Mediated Supersymmetry Breaking Model

• In AMSB SUSY breaking via superconformal anomaly

• Free parameter of Minimal AMSB

• Wino-like neutralino• Mainly annihilate to

WW pair• Other channel-ZZ, Zh,

top pair3/ 2 0, , tan , ( )m m sign

1

0 11 12 13 14d uN B N W N H N H

Weihai, July 8-12

Weihai, July 8-12

Weihai, July 8-12

Weihai, July 8-12

Helicity effects and secondary neutrinos

• Transverse polarized W boson• Leptonic decay and hadronization

By spin and momentum conservation

Weihai, July 8-12

Other annihilation channel• Z boson in Zh channel is longitudinal polarized• ZZ is similar to WW

Weihai, July 8-12

Propagation of neutrinos to Earth

• Density evolution equation of propagation

• Vacuum oscillation

• Neutrino scattering

• Neutrino absorption and tau-neutrino re-injection

• Monte carlo simulation-WimpSim

0

[ , ]NC CC

d d d di H

dr dr dr dr

hep-ph/0506298

Weihai, July 8-12

IceCube neutrino detector• Surpass the sonic barrier • Muon surpass the speed

of light

• Cerenkov light passing through the IceCube neutrino detector

• Courtesy

Steve Yunck/NSF

Weihai, July 8-12

IceCube neutrino detector

Weihai, July 8-12

Atmosphere neutrino background

• Cosmic ray interacts with atmosphere around the Earth, produces high energy neutrinos which can result in muons in detector

• Such neutrino have no special direction, thus can be reduced by angle cut of IceCube

Weihai, July 8-12

Angular distribution of muons

• Angle of muon velocity • In range

• Most of Muons are within 2 degree

• Important information to reduce spherical homogeneous atmosphere neutrino background

10

100 1GeV m TeV

Weihai, July 8-12

Muon spectrum and backgrounds

Weihai, July 8-12

Benchmark Points

Weihai, July 8-12

A rule in thumb

• Possible to observe muons

at IceCube if510SD pb

Weihai, July 8-12

Summary for part 2• Neutralino annihilation in Sun produces high

energy neutrinos• Neutrinos propagate to IceCube from Sun• The condition for muon detection in AMSB

• The angular distribution of signal muons

• Angular distribution is crucial to reduce atmosphere neutrino backgrounds

510SD pb

2

Weihai, July 8-12

3. Constraints on the Dark matter Annihilations by Neutrinos with Subs

tructure Effects IncludedPeng-fei Yin, Jia Liu, Qiang Yuan, Xiao-jun Bi and Shou-hua Zhu, arXi

v:0806.3689.

Weihai, July 8-12

Motivation

• Cross section of neutrino and matter increases rapidly with the increment of neutrino energy

• No excess observed for atmospheric neutrino up to 10 TeV

• Constraints for high energy neutrino flux

Weihai, July 8-12

Why DM substructure? Take visible matter as example!

Weihai, July 8-12

Why substructure?

• The principal component of the Solar System is the Sun, that contains 99.86% of the system's known mass and dominates it gravitationally

• Jupiter and Saturn, the Sun's two largest orbiting bodies, account for more than 90% of the system's remaining mass.

Weihai, July 8-12

Why substructure?

• Galactic center (GC) has the largest neutrino flux due to DM annihilation. However GC has also the largest backgrounds, for example black hole.

• Substructure may be background free, and ‘bright’ enough.

Weihai, July 8-12

How to proceed?

We need to know:

• Galactic DM and substructure distribution

• Constraint on the dark matter annihilation cross section by atmospheric neutrino

Weihai, July 8-12

The neutrino flux from the DM annihilations

depend on the particle property

depend on the spatial distribution of DM

( , ) ( ) ( )E C W E J

2 22 2

1 1( )

4 2 LOS

v dNR l dl

m dE R

( )W E

( )J

Weihai, July 8-12

Astrophysical factor of the DM annihilation

• To account for the contribution of substructures, we use

We fix the smooth distribution of DM to NFW profile• The average astrophysical factor is defined as

is the half angle of the cone centered at the direction of the GC

2 2 2smooth sub

2 22( )

4 subsub sub subV

sub

dNdM dV

dM r dr

1( )J J d

2 (1 cos )

Weihai, July 8-12

Galactic DM distribution profile • A general DM distribution profile that fits the simulations is :

• Different parameters denote deferent profiles. NFW profile: 1.5, 3.0, 1.5 Moore profile: 1.0, 3.0, 1.0

• Especially the cored profile could be or other cuspy form.

( ) /( )

( / ) [1 ( / ) ]s

s s

rr r r r

( , , )

2(1 / )[1 ( / ) ]s

s sr r r r

J. F. Navarro et al. , Astrophys. J. 490, 493 (1997) .

B. Moore et al. , Astrophys. J. 499, L5 (1998) .

A. Burkert, Astrophys. J. 447, L25 (1995).

Weihai, July 8-12

Determination of the profile parameters

• We require the virial mass

• Virial radius

amplifying factor over the background

critical density of the universe • Concentration parameter

• The unknown parameters and can be determined by

. Generally this relationship is fitted from the numerical simulation.

s sr

1/3( )(4 / 3)

vv

c

Mr

200

3139c sunM kpc

2

22/ , ( ) / 0v v r r

c r r d r dr

( )vM r dV

v vc M

J. S. Bullock et al. , Mon. Not. Roy. Astron. Soc. 321, 559 (2001)

Weihai, July 8-12

Determination of the profile parameters

• In our work, we use two models to determine the

We use the fitted polynomial form and extrapolate to low masses 4

0

( ) [ ]i

vv i

i sun

Mln c C ln

M

01 4{3.14, 0.018, 4.06 10 ,0,0}ENSiC

01 4 6 7{4.34, 0.0384, 3.91 10 , 2.2 10 , 5.5 10 }BiC

v vc M

• ENS01

• B01

• The above models are from the simulations which generate sub-halos within a distinct halo. For the host ones,

B01-sub or B01X2 0.3

v vC M 012 Bv vC C

J. S. Bullock et al. , Mon. Not. Roy. Astron. Soc. 321, 559 (2001).

V. R. Eke et al., Astrophys. J. 554, 114 (2001).

J. S. Bullock et al. , Mon. Not. Roy. Astron. Soc. 321, 559 (2001).

S. Colafrancesco et al., Astron. Astrophys. 455, 21 (2006).

Weihai, July 8-12

Determination of the profile parameters

• The relation of at epoch Z=0v vc M

Weihai, July 8-12

The Galaxy halo and substructure

• We adopt as the mass of the Galaxy halo.• Simulations give the number density of sub-halos an

isothermal spatial distribution and a power-law function

we adopt core radius ,

sub-halos mass range: • Tidal effect: In the inner region of the host halo, strong

tidal force tends to destroy the sub-halo.• We find the mass fraction of substructure is about 14% .

12~10v sunM M

02 2

1( )

4 1 ( / )asub

sub host H

MdNN

dM r dr M r r

0.14H vr r 1.9a 6 1210 ~10sun sunM M

Weihai, July 8-12

Astrophysical factor of the DM annihilation

• Astrophysical factor with concentration models as ENS01

Weihai, July 8-12

Astrophysical factor of the DM annihilation

• Astrophysical factor with concentration models as B01

Weihai, July 8-12

Astrophysical factor of the DM annihilation

• Astrophysical factor with concentration models as B01X2

Weihai, July 8-12

DM substructure as point-like source• The massive sub-halo can be treated as point-like source

and may be identified by high angular resolution detector.

6( 10 ) 6400sunN M

• We use a Monte-Carlo

method to generate

average within the cone with half angle

01( )J

Weihai, July 8-12

Astrophysical factor of the DM annihilation

Weihai, July 8-12

Atmospheric neutrino

• The main backgrounds detected by Cerenkov detectors are from cosmic ray interacting with the atmosphere of the earth, which have no special direction.

• There are no excess beyond the theoretical prediction of the atmospheric neutrino. The null results can be used to set the upper bound of the DM annihilation cross sections.

• We use the flux of atmospheric neutrino from

M. Honda et al. Phys. Rev. D 75, 043006 (2007).

Weihai, July 8-12

Particle Physics factor of the DM annihilation

• We use the assumption that the productions of DM annihilation are only neutrinos.

In fact DM may annihilation into final states other than neutrinos. Moreover high energy neutrinos from the DM annihilation will

lead to gauge bosons bremsstrahlung

• The spectrum of neutrinos per flavor is a monochromatic line we average neutrino flux within the energy bin

around

2/ ( )

3v v v DMdN dE E m

J. F. Beacom et al. , Phys. Rev. Lett. 99, 231301 (2007) ; H. Yuksel et al. , Phys. Rev. D. 76, 123506 (2007).

M. Kachelriess, P.D. Serpico, Phys. Rev. D 76, 063516 (2007) ; N. F. Bell et al., arXiv: 0805.3423.

v DME m10log 0.3E

Weihai, July 8-12

Final Results• By requiring the neutrino flux does not exceed the atmospheric

neutrino flux, we give the upper bound to the DM annihilation cross section .

Weihai, July 8-12

Summary for part 3• By requiring the DM induced neutrino flux less than

the measured ones, we give the improved upper bounds on the DM annihilation cross section.

• Considering substructure average contribution over all directions, the bound are improved by several times.

• Considering single massive sub-halo as point source, the bound can be improved by 10^1~10^4 utilizing the angular resolution of IceCube. In some model, IceCube can achieve the sensitivity of DM annihilation cross section as 10^-26 cm^3s^-1.

Weihai, July 8-12

4. Summary of the talk

• Besides the central issue of electroweak symmetry breaking, LHC may also touch the properties of dark matter.

• More information of dark matter may come also from the sky, i.e. from the observation of neutrino by neutrino telescope (with excellent angular resolution).

Thank you!

Weihai, July 8-12

Dark Matter

• Non-luminous matter with gravitation effects

• Galactic rotation curves

• Cold dark matter by analyses of structure formation

• WMAP

2 0.111 0.006nbmh

2 0.023 0.001bh From SUSY07 public lecture

来自 PDG

Weihai, July 8-12

Candidate for Dark Matter

Conditions

• Stable on cosmological time scales

• Very weak electromagnetic radiation

• Right relic density

Candidates

• Weakly interacting massive particles(WIMP)

-Neutralino in Supersymmetry

• Primordial black holes, Axions

来自 PDG

Weihai, July 8-12

Experiment for Dark Matter

Direct WIMP search• Detection of nuclear recoils• Cryogenics detector, Noble liquid• No positive identification• XENON10Indirect WIMP search• WIMP annihilation and decay• Photon, neutrino, positron, anti-nuclei

84.5 10SIp pb

PRL 100， 021303

Weihai, July 8-12

DM detected methods• We confirm the existence of the DM only through the

gravitational effects, the rotation curves of spiral galaxies, the gravitational lensing, the dynamics of galaxy clusters…

• Collider detection, LHC, ILC…• Direct detection, XENON, DAMA, ZEPLIN, CDMS…• Indirect Direct detection,

• Gamma-Ray experiments,

Ground-based, MAGIC, HESS, ARGO…

Space-based, GLAST, EGRET…• Anti-matter experiments, HEAT, BESS, AMS…• Neutrino experiments, Super-kamiokande, IceCube, ANTARES…

Weihai, July 8-12

Other strategies of detecting neutrinos

• Explore the neutrinos from the extra-galactic

explore the neutrinos from the galactic center (GC)

H. Yuksel et al. , Phys. Rev. D. 76, 123506 (2007).

J. F. Beacom et al. , Phys. Rev. Lett. 99, 231301 (2007) .