LHC and CosmologyHitoshi Murayama (IPMU Tokyo, Berkeley)

APS Meeting@Denver, May 3, 2009

There are many things we don’t see

Energy Budget of the Universe

• Stars and galaxies are only ~0.5%

• Neutrinos are ~0.1–1.5%

• Rest of ordinary matter (electrons, protons & neutrons) are ~4.4%

• Dark Matter ~23%

• Dark Energy ~73%

• Anti-Matter 0%

• Dark Field (Higgs) ~1062%??

starsneutrinosbaryondark matterdark energy

3

Dark Matter

Solar system revolves at 220km/srequires a lot of mass to keep it inside Milky Way

collision at 4500 km/sec

You don’t want to be there

Cosmological scales

7

matterall atoms

= 5.70+0.39!0.61

• Cold and Neutral

• dark matter must be non-relativistic and clump together by gravitational attraction

• must be electrically neutral

• lifetime longer than age of the Universe

• beyond that, rather little

What do we know?

• must clump to form galaxies, clusters

• imagine

• “Bohr radius”:

• too small m ⇒ won’t fit in a galaxy!

• m >10−22 eV “uncertainty principle” bound (modified from Hu, Barkana, Gruzinov, astro-ph/0003365)

V = GNMm

rrB =

!2

GNMm2

Mass Limits“Uncertainty Principle”

Search for MACHOs(Massive Compact Halo Objects)

Large Magellanic Cloud

Not enough of them!

Dim Stars?

10

MACHO

95% cl

0.2

!6 !2!8 !4 0 20.0

0.4

0.6

f =

!7

EROS!2 + EROS!1upper limit (95% cl)

logM= 2log( /70d)tE

EROS collaborationastro-ph/0607207

• 10-31 GeV to 1050 GeV

• narrowed it down to within 81 orders of magnitude

• a big progress in 75 years since Zwicky

SummaryMass Limits

• if self-coupling too big, will “smooth out” cuspy profile at the galactic center

• some people wanted it (Spergel and Steinhardt, astro-ph/9909386)

• need core < 35 kpc/h from data

σ < 1.7 x 10-25 cm2 (m/GeV)(Yoshida, Springel, White, astro-ph/0006134)

• bullet cluster:

σ < 1.7x10-24 cm2 (m/GeV)(Markevitch et al, astro-ph/0309303)

Self-Coupling

• dominant paradigm: WIMP (Weakly Interacting Massive Particle)

• Stable heavy particle produced in early Universe, left-over from near-complete annihilation

MACHO ⇒ WIMP

ΩM =0.756(n +1)x f

n+1

g1/2σannMPl3

3s08πH0

2 ≈α 2 /(TeV)2

σann

• thermal equilibrium when T>mχ

• Once T<mχ, no more χ created

• if stable, only way to lose them is annihilation

• but universe expands and χ get dilute

• at some point they can’t find each other

• their number in comoving volume “frozen”

G. Jungman et al. JPhysics Reports 267 (1996) 195-373 221

Using the above relations (H = 1.66g$‘2 T 2/mpl and the freezeout condition r = Y~~(G~z~) = H), we

find

(n&)0 = (n&f = 1001(m,m~~g~‘2 +JA+)

N 10-S/[(m,/GeV)((~A~)/10-27 cm3 s-‘)I, (3.3)

where the subscript f denotes the value at freezeout and the subscript 0 denotes the value today.

The current entropy density is so N 4000 cmm3, and the critical density today is

pC II 10-5h2 GeVcmp3, where h is the Hubble constant in units of 100 km s-l Mpc-‘, so the

present mass density in units of the critical density is given by

0,h2 = mxn,/p, N (3 x 1O-27 cm3 C1/(oAv)) . (3.4)

The result is independent of the mass of the WIMP (except for logarithmic corrections), and is

inversely proportional to its annihilation cross section.

Fig. 4 shows numerical solutions to the Boltzmann equation. The equilibrium (solid line) and

actual (dashed lines) abundances per comoving volume are plotted as a function of x = m,/T

0 .01

0 .001

0.0001

10-b

,h 10-s

-; 10-7

c aJ 10-a a

2

10-Q

p lo-‘9

$ lo-”

z 10-m

F! lo-‘3

10 100

x=m/T (time +)

Fig. 4. Comoving number density of a WIMP in the early Universe. The dashed curves are the actual abundance, and

the solid curve is the equilibrium abundance. From [31].

thermal relic

ΩM =0.756(n +1)x f

n+1

g1/2σannMPl3

3s08πH0

2 ≈α 2 /(TeV)2

σann

Finding Dark MatterDirect detection

detector

neutralino

phonon or photon

nucleus

underground laboratory

XMASS800kg LXe

Finding Dark MatterIndirect method

neutralino

!!"##X

## detector

Earth Sun

Ener gy (GeV)

Posit

ron

fract

ion,

(e

+ ) /

((e

+ ) +

(e

– ))

ref. 1PAMELAAesop (ref. 13)HEAT00AMSCAPRICE94HEAT94+95TS93MASS89Muller & Tang 1987 5,6

0.01

0.02

0.1

0.2

0.3

0.4

10!1 1 10 102

PAMELAe+PAMELA

FERMIe+ + e–FERMI

More in session Q8tomorrow 10:45

Nambu-GoldstoneDark Matter

• gauge mediation of SUSY breaking ~100TeV• pseudoNambu-Goldstone boson X ~ 3 TeV• R-axion a ~ GeV, decays to μ+μ-

• annihilation X X→a a→(μ+μ-)(μ+μ-)

BF=2500=overdensity×Breit-WignerIbe, HM, Shirai, Yanagida, in preparation

IbeNakayama

HMYanagida

0902.2914

need for enhancement

• At the freezeout, we need ‹σv›∼10-9GeV-2

• In the galactic halo, we need ‹σv›BR∼10-7GeV-2

• How do we reconcile them?• non-thermal relics• enhancement in the (halo density)2

• attractive force between dark matter particles (Sommerfeld enhancement)

• Our proposal: s-channel resonance just below threshold (Breit-Wigner enhancement)

Breit-Wigner enhancement

• s=4m2+vrel2

• If resonance M is below threshold 4m2, not accessible vrel2<0

• early universe, does not see the BW tail very much

• in halo, dark matter does see the tail

• called “ghost” in nuclear physics

!4 !2 0 2 4 6 8 10vrel2/(10!3c2)

Breit

-Wign

er

small v0

large v0

Nambu-GoldstoneDark Matter

• gauge mediation of SUSY breaking ~100TeV• pseudoNambu-Goldstone boson X ~ 5 TeV• R-axion a ~ GeV, decays to μ+μ-

• decay X→a a→(μ+μ-)(μ+μ-)

IbeNakayama

HMYanagida

0902.2914

τ=1.3×1026 secIbe, HM, Shirai, Yanagida, in preparation

prediction

• bumps in diffuse gamma

annihilation decay

SUSY spectrum

• no dark matter (3-5 TeV) at LHC, but associated SUSY particles within LHC

• The model predicts light gauginos

• gluino < 1 TeV, wino < 300 GeV

• very light gravitino m3/2<16eV with no cosmological problem

• a lot to learn from LHC!

Recreating Big Bang

start this year!

Large Hadron Collider (LHC)

24

Standard WIMP

• SUSY, Universal Extra Dimensions, Little Higgs with T-parity, Warped Extra Dimension, .....

• Can produce dark matter directly at LHC

• missing ET signature

• details depend on models, parameters

Producing Dark Matter in the laboratory

• Mimic Big Bang in the lab• Hope to create invisible

Dark Matter particles • Look for events where

energy and momenta are unbalanced

“missing energy” Emiss

• Something is escaping the detector

⇒Dark Matter!?

4.8Gev EC19.Gev HC

YX hist.of BA.+E.C.0| ! 500cm 500cm|X

0|!500cm

500cm|

Y

26

Supersymmetric Dark Matter

1

10

102

103

104

105

0 1000 2000 3000 4000

ATLAS

Meff

(GeV)

d!

/dM

eff (

Events

/200 G

eV

)

Background

Signal+BG

" !4jets pT>50GeV

" !2jets pT>100GeV

ETmiss>100GeV

ETmiss>ET

sum/4

ST>0.2!

no µ, e in |#|<2.5

Supersymmetryamazing reach Can do many precision

measurements at LHC! L dt = 1, 10, 100, 300 fb-1

A0= 0, tan! = 35, µ > 0

ET

(300 fb-1)miss

ET

(100 fb-1)miss

ET

(10 fb-1)miss

ET

(1 fb-1)miss

g(1000)~

q(1500)

~

g(1500)~

g(2000)~

q(2500)

~

g(2500)~

q(2000)

~

g(3000)~

q(1000)

~

q(500)

~g(500)~

!h2 =

0.4

!h2 =

1

!h 2 =

0.15

h(110)

h(123)

1400

1200

1000

800

600

400

200

50000

1000 1500 2000

m0 (GeV)

m1

/2(G

eV

)

EX

TH

CMS

one year

@1033

one year

@1034

one month

@1033

Fermilab reach: < 500 GeV

one week

@1033cosmologically plausible

region

0

50

100

150

200

250

300

350

400

0 50 100 150 200 250 300 350 400

S5

O1

M! (GeV)"1

0

Ml (

Ge

V)

" R

q

q

W l

l

q’_

g~

g~

g~~

~

~l

0

b

b

W l

l

b

_

~~

~l

0

missing ET, multiple jets, b-jets, (like-sign) di-leptons

SUSY

P80

P80

P80

t

t

t

t

b

b

b

W

W

W

l

l

l

l

q

q’_

_

_

_

q

q’_

W

b

_

technicolor

+little Higgs with T-parity, warped ED with Z3 baryon

New physics looks alike

28

UED

q1

q

W1 l

1l

q’ _

g1

g1

g1 l

t1

b

W1 l

1l

t

_ l

B1

B1

spin 1/2spin 1 spin 0

• Electron-positron collider

• Super-high-tech machine

• Accelerate the beam over ten miles

• Focus beam down to a few nanometers and make them collide

• Precisely measure the dark matter properties

International Linear Collider (ILC) e

lec

tron

so

urc

es

(HE

P a

nd

x-ra

y la

se

r)

linearaccelerator

linear accelerator

x-ra

y la

se

r

ele

ctro

n-p

os

itron

co

llisio

nh

igh

en

erg

y p

hy

sic

s e

xp

erim

en

ts

po

sitro

n s

ou

rce

au

x. p

ositro

n a

nd

2n

d e

lectro

n s

ou

rce

da

mp

ing

ring

da

mp

ing

ring

po

sitro

np

rea

cc

ele

rato

r

e-

e+

e-

33 km

Linear Collider

29

Omega from colliders

SUSY case studyBaltz, Battaglia, Peskin,

Wizansky hep-ph/0602187

How do we know what Dark Matter is?

• cosmological measurement of dark matter

• abundance ∝ σann−1

• detection experiments• scattering cross section

• production at colliders• mass, couplings • can calculate cross sections

• If they agree with each other:⇒ Will know what Dark Matter is

⇒ Will understand universe back to t∼10-10 sec

mass of the Dark Mattercosm

ic a

bundance

WMAP

LHC

ILC

31

400Kyr

13.7Byr

1min10 -10sec

Conclusion

• Major puzzles at the intersection of particle physics and cosmology

• TeV energy scale appears relevant• Dark Matter, Dark Field

• Possibly also origin of baryon asymmetry• We are finally getting there with LHC!• combine LHC with underground, astro,

cosmic ray, CMB, followed by LC