Dark Universe

Jonghee Yoo
Korea Advanced Institute of Science and Technology
Institute for Basic Science

21 September 2018
TGSW2018: Evolution of the UniverseTsukuba

The Bright Side of the Universe

B.Nord (Fermilab)
Cerro Pachón, ChilleYoo-2018-09-21-TGSW: Dark Universe2

Evolution of the Universe
NASA/WMAP Science Team

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Hubble Constant
Velocity-Distance Relation among Extra-Galactic Nebulae (Hubble 1929)

Expansion rate
~500km/s/Mpc

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4Type Ia Supernova: Standard Candle
Hubble Telescope Image (NGC4526, SN1994D)

Yoo-2018-09-21-TGSW: Dark Universe5Modern Hubble Diagram: Accelerating Universe
Totally unexpected discovery
in 1998 by two independent
observatory teams

High-z SN Search Teammeasurements
Expansion rate
~70km/s/Mpc(1) High-z SN Search Team(2) Supernova Cosmology Project
Accelerating Universe!

Nobel Prize in Physics 2011
Saul Perimutter
Brian P. Schmidt
Adam G. Riess

Hubblefor the discovery of the accelerating
expansion of the Universe

Recall a Friedmann equation:> 0 (?)✓
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z=oee=anowathen◆
1Acceleration?
Negative pressure?
6Cosmological Constant: Dark Energy(?)# ΛCDM ModelGµ⌫ + ⇤gµ⌫ = 8⇡GTµ⌫gravity (matter)ä=a4⇡G⇤(⇢ + 3P ) +33slows down
expansion

9.4×10-5~0.32

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dark energy<0.01

speeds up
expansion

0.68

1 = ⌦r + ⌦m + ⌦k + ⌦⇤7

Dark Energy

70% of the energy budget of the universe is Dark Energy!
30% is matter component…
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Fritz Zwicky (1933): Coma Galaxy Cluster

1933 Fritz Zwicky found evidences for dark matter in the Coma galaxy cluster(consisted of approximately 1,000 galaxies.) by studying the velocity of the galaxies
in the cluster. He found the light output per unit mass from the cluster fell short ofthat from gravitational mass of the cluster.
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Rotation Curve of Galaxy
Observed?
Expectedfrom Newtonian Gravity

M33 Rotation Curve

1970s Vera Rubin studied the rotation curve of galaxies (speed of stars) andfound inconsistency between the velocity distributions predicted by Newton’s
gravitational law and the velocity distribution of stars.
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10Dark Matter: Galaxy Clusters

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Dark Matter: Bullet Cluster Collision

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12Cosmic Microwave Background (CMB)

Snapshot of theUniverse 380,000years after the BigBang

13,700,000,000 years
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CMB Anisotropy

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Universe is Dark

● We know that Dark Matter isstablenon-baryonicnon-relativistic
interacts gravitationally● We don’t know what it actually is:mass ?
coupling ?
spin ?
composition ?
distribution in the Universe …

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Dark Matter Distribution

Invisible Component of Matter Halo

We are here

200 kpc
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Direct Detection of WIMP

WIMPs (Weakly Interacting Massive Particles)
coherently scatter from the entire nucleus⇥ N'

4µ2 [Zfp + (AZ)fn ]2

Differential Event Rate in Recoil Energy @mD=60 GeV(a)

(b)
χXeχ

HGeAASi

Michael Attisha

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CEvNSGF µl jµ
Lef f =
2Cross section for zero-momentum transfer limit⇥ N '42E [Z⇤p + (Ag(Z0 u) =⇥p =142sin2 W ,3GF
(4 sin2 W
4Z)⇤n ]

1 1+ sin2 W
4 3g(Z0 d) =1),

⇥n =

2GF
4Differential cross section for finite momentum transferG2Fd⇤=[(1dE4⇥4 sin

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2w )Z(A2Z)] M✓

1ME
2E 2◆F (Q2 )218

Coherent Elastic Neutrino-Nucleus Scattering
Coherent scattering observed in Lepton sector (ORNL, by COHERENT Collaboration)2017 September 15
Michael Attisha

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XENON 1T Experiment

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XENON 1T Experiment

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XENON 1T Experiment

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Axion as a Dark Matter

Invented to solve the strong-CP problem in QCD• Non-thermal mechanism of producing
axion dark matter in the early Universe• The initial axial angle Θ determines
the potential energy to be released.
• The potential energy density(order of ΛQCD4) is converted into
cold dark matter

ΛQCD4

VEV : fa > 109GeV

Yoo-2018-09-21-TGSW: Dark Universe• Axion dark matter mass is determinedby the harmonic oscillator frequencyma ≃ ΛQCD2/fa < 10-3 eV !

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Axion Dark Matter Search

SOLAX/DAMA/CDMS

Axionic
Dark Matterplayground

Warmdark matterΩa>1NN➜NNaDFSZ

Axion potential energy decays at time t~1/ma.
If this is too late (too small ma) in cosmological timethe dark matter can be overproduced relative to the photons
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Axion Dark Matter Search in A Nutshell
Assume:aB0

Strong B-field magnet

Strong B-field magnet

RF antennaHigh Q cavity

Oscillating source current ➜ RF photons
RF photon frequency = axion mass
Yoo-2018-09-21-TGSW: Dark Universe~ 10-21W at ma=μeV(assuming B=8T, V=0.2 m3 magnet and cavity Q =105)
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Axion Dark Matter eXperiment (ADMX)• ADMX collaboration (hosted at the University of Washington)• “Currently (2017)” the world most sensitive dark matter axion search experiment• The experiment started in 1995 — more than 20 years of efforts• Relatively low magnetic field (8 Tesla) but large volume (140 liter, Q~60,000)• Probing low mass (~𝜇eV) axions

Cancellation Coil
SQUID
Refrigeration
Antennas
8T MagnetCavity

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Linear Amplifier: Quantum Noise Limit
J. Clarke

Time to scan axion DM mass range
using 2010 technology ➜ 100-years!

Improve scan speed

TN = Tamplifier + Tphysics
Bath temp (mK)Run colder to reduce thermal noise!
➜ Use dilution refrigerator (~50mK)➜ Quantum limited amplifiers- Microstrip SQUID Amplifier (<1GHz)- Josephson Parametric Amplifier (>1GHz)

The scan speed can be improved by factor >100
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ADMX 2G Results (2018)

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Center for Axion and Precision Physics Research (CAPP)

CAPP/IBS at KAIST University launched in October 2013
Physics

Host Institution

Human Resource- Axion Search- Proton EDM- Muon g-2 / mu2e

- KAIST University- IBS (Institute for Basic Science)- 25 researchers- 20 graduate students- 7 staffs (admins/techs)- Visiting scholars

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Daejeon: A City of Science in Korea

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Daejeon: A City of Science in Korea
Astrophysics
Research Center

KUMHO Chemical
Central Research Center

Golf Course for Scientists
Korea Telecomunication
Research Center

MechanicalEngineering
Research Center

Samyang
Research Center

KEPCO Electric Power
Research Center
Commercial Satellite
Company
Samsung
Research Center

KRISS
ChemicalResearch Center

KAIST Munji Campus
Korea Science
Funding Agency

Geology
Research Center

LG Chemical
Research Center

Aerospace
ResearchCenter

SK Technology
Research Center

KSTAR
KBSI

Convention Center

KAIST Main Campus

IBS Headquarter
Patent SchoolYoo-2018-09-21-TGSW: Dark Universe

Industrialand business Area

Science Musieum
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CAPP’s Dark Matter Axion Search Strategy
Strong magnetic field (18T → 25T → 35T)

Lower the thermal noise temperature(cryogenics & low noise amplifier)Yoo-2018-09-21-TGSW: Dark Universe

High Q cavity (Q~106)32

Experiment Hall
Low vibration facility
More than five large scale axion searchexperiments can be hosted

CAPP18T3m

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18T HTS Magnet @ KAISTWorld strongest magnet inAxion Dark Matter Search Experiment
Note: df/dt ~ B4V2/T2
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18T HTS Magnet Field Map# 18T magnet field map simulation➔ Shielding magnet design➔ Safety margin
Length of the Magnet (467.8mm)

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18T HTS Magnet Performance

initial shortterm test

18T full-charge long term (unattended) operation2017.10.30 — 2017.11.15

Current (stable 0.05%)

Stand alone operation
Field stability: better than 0.05%
Large safety margin: ~21T engineering design
B-field

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DAQ

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Cavity and Tuning-Rod Performance (4K Test)

TM010 mode

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Josephson Parametric Amplifier (JPA/JPC)

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Gain(20 dB min)Fmin (GHz)fmax (GHz)High frequency

7.72

8.802

Low frequency

4.757

5.0139Dilution Refrigerator< ~30mK physical base temperature achieved (2018 March)
Note: df/dt ~ B4V2/T2
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CAPP Dark Matter Axion Search Schedule201718T/7cmCAPP18T(SuNAM)

setup

2018

2019

2020

2021

2022

experiment

25T/10cm
CAPP25T(BNL)

setupexperiment

12T/32cm
CAPP12T(Oxford)

setup

experiment

There are R&D efforts for higher mass dark matter axion search (>40µeV)
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Prospect of Axion Dark Matter Search at CAPP

l of Caog
2Gperim
APP exents

Stay tuned! Discovery of the dark matter axions maybe around the corner!
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42Evolution of the Universe
NASA/WMAP Science Team

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The Universe• It’s big~1024 km• It’s old~1010 years• It’s dark

~95%