direct detection of composite dark matter...wimps, hidden sector, asymmetric, etc high number...

D.M. Grabowska BSM Circa 2020 03/01/2019

Direct Detection of Composite Dark Matter

Dorota M Grabowska

UC Berkeley and LBL

Work with: - A. Coskuner, S. Knapen, & K. Zurek arXiv: 1812.07573

- T. Melia and S. RajendranarXiv: 1807.03788

https://arxiv.org/abs/1812.07573


Dark Matter Mass LandscapeAllowable mass range covers ~ 90 orders of magnitude

Ultra Light DM

Axions, ALPS, etc

Classically coherent fields compensate for weak

coupling

Particle DM

WIMPs, Hidden Sector, Asymmetric,

etc

High number density compensates for small

cross sections

Macroscopic DM

Primordial Black Holes, MACHOS,

etc

High mass compensates for

weakness of gravity

zeV keV PeV 1050 GeV 1060 GeV

2



Ultra Light DM

Axions, ALPS, etc

Classically coherent fields compensate for weak

coupling

Particle DM

WIMPs, Hidden Sector, Asymmetric,

etc

High number density compensates for small

cross sections

Macroscopic DM

Primordial Black Holes, MACHOS,

etc

High mass compensates for

weakness of gravity


2

(103 M☉)(10 -21 eV)



3


DM flux at least one per year

Earth

Xenon OneTon

Olympic Swimming Pool

(Distance from Earth to Sun)3

1010 GeV 1042 GeV1033 GeV1019 GeV 1022 GeV


1. Dark Matter candidates in this mass regime

1. Take Away: Bound states of strongly interacting dark sectors can span full regime

2. Possible Detection Strategies

1. Take Away: Need multi-prong experimental and observational approach

4

Plan


1. Dark Matter candidates in this mass regime

1. Take Away: Bound states of strongly interacting dark sectors can span full regime

2. Possible Detection Strategies

1. Take Away: Need multi-prong experimental and observational approach

4

Plan

Take Away: Need multi-prog experimental and observational approach

Take Away: Bound states in strongly interacting dark sectors have masses that span ~40 orders of magnitude


• Relic abundance set by dark baryon asymmetry

Strongly Interacting Dark Sector

5

Example: Dark Nuclear Matter

“Dark Nucleon”

“Dark Nucleus”

General Properties

• Theory confines at energy scale ΛΧ• Spectrum contains massive particle with mx ~ Λx

• Massive particles form bound states with Mx ~ Nx Λx


Treat dark nucleus as drop of liquid to determine how binding energy depends on number of constituents

Maximum Size of Dark Nucleus

6

Semi-empirical mass formula

• Assume no long range force to destabilize dark nuclei

Binding energy unbounded from above!


Treat dark nucleus as drop of liquid to determine how binding energy depends on number of constituents

Maximum Size of Dark Nucleus

6

Semi-empirical mass formula

Short Range Strong Interaction

Surface Correction

Long Range Weak Interaction

• Assume no long range force to destabilize dark nuclei

Binding energy unbounded from above!

D.M. Grabowska BSM Circa 2020 03/01/2019 7

Early Universe FormationBig Bang Dark Nucleosynthesis

Dark nuclei form via fusion processes in the Early Universe

“Nuclear Physics”

* Krnjaic & Sigurdson, ’14, Hardy et al, ’14, Gresham, Lou & Zurek, ’17


Dark nuclei size is limited by how long fusion lasts during early Universe

• Compare Fusion rate to Hubble rate for rough estimate

• Generically find exponentially large states

Dark BBN

8

Fusion in Early Universe


Dark Nuclear Matter“Dark Nuggets”

*Gresham, Lou and Zurek, 1707.02316


Detection


Dark Matter Direct DetectionDM Scattering

General Idea: DM passes through detector, resulting in either nuclei/electron recoil or collective mode excitation

DM

SM Detector

pi pf

Differential Scattering Rate per Unit Target Mass


Dark Matter Direct DetectionDM Scattering

General Idea: DM passes through detector, resulting in either nuclei/electron recoil or collective mode excitation

DM

SM Detector

pi pf

Differential Scattering Rate per Unit Target Mass

Target and DM Dependent!


Dynamic Structure FunctionParameterizes Target Response

General Idea: Structure Function S(q, ω) quantifies response of target to injection of momentum, q, and energy, ω


Dynamic Structure FunctionParameterizes Target Response

General Idea: Structure Function S(q, ω) quantifies response of target to injection of momentum, q, and energy, ω

DM Velocity Dist.

Target ResponseDM Form Factor

Mediator “Form Factor”

DM Number Density


Standard Model CouplingsNucleon Coupling

General Idea: Dark Matter couples to Standard Model nucleons via mediator of mass mφ

Results in spin-independent four fermion interaction with specific mediator “form factor”


DM Form FactorFinite Size effects

10-2 10-1 100 101 102

10-6

10-3

100

q (1/RX)

|FX(q)2

Coherent Incoherent

General Idea: Form factors “encode” the deviation of scattering amplitudes from the point particle limit


Short Range Mediator


Nuclear RecoilTraditional WIMP Search

General Idea: Dark Matter scatters of single nucleus, which then recoils

Effect of DM’s finite radius on detectability depends on how much of scattering phase space is suppressed by form factor


Nuclear RecoilTraditional WIMP Search

General Idea: Dark Matter scatters of single nucleus, which then recoils

On-Shell recoilForm Factor of Nucleus

Effect of DM’s finite radius on detectability depends on how much of scattering phase space is suppressed by form factor


Form Factor Effects

General Idea: Effect of form factor depends on how DM radius compares to qmax and qmin

• ss: : Cross section for point-like DM scattering off nucleon

Massive Mediator

Maximizing target’s atomic number is key

17


Short Range Mediator10 GeV

103 106 109 1012 1015 101810-48

10-45

10-42

10-39

10-36

10-33

10-30

10-27

10-24

10-21

10-18

10-48

10-45

10-42

10-39

10-36

10-33

10-30

10-27

10-24

10-21

10-18

MX (GeV)

σ Xn(cm2 )

mχ=10 GeV, Fmed = 1

LiquidXe, 1.5*104 kg

year, E

thres=5keV

XENON1T,

98 kgyear,

Ethres=5 ke

V

He (Nuclea

r Recoil), k

g year, Ethre

s=1meV

Geometric Cro

ss Section

Overburden

*Coskuner, DMG, Knapen & Zurek ‘18


Short Range Mediator10 GeV

Collider Constraints

103 106 109 1012 1015 101810-48

10-45

10-42

10-39

10-36

10-33

10-30

10-27

10-24

10-21

10-18

MX (GeV)

σ Xn(cm2 )

mχ=10 GeV, Fmed = 1LiquidXe, 1.5*104 kg

year, E

thres=5keV

XENON1T,

98 kgyear,

Ethres=5 ke

V

Semicond

uctor(Ge),

100 kg yea

r, Ethres=50

eV

CDMSLite

, 0.2kg ye

ar, Ethres=0

.5 keV

Semicondu

ctor (Si), kg

year,Ethres

=10 meV

He (Nuclea

r Recoil), k

g year, Ethre

s=1 meV

Geometric Cros

s Section

Overburden

10-9

10-6

0.001

1

1000

106

gXgnMXμ XN/(M

Nm

ϕ2 )

(1/GeV

)



Short Range Mediator10 MeV

100 103 106 109 1012 101510-42

10-39

10-36

10-33

10-30

10-27

10-24

10-21

10-18

10-15

10-12

10-42

10-39

10-36

10-33

10-30

10-27

10-24

10-21

10-18

10-15

10-12

MX (GeV)

σ Xn(cm2 )

mχ=10 MeV, Fmed = 1, 1% subcomp. DM

LiquidXe, 1.5*104kgyear, E

thres=5keV

XENON1T,98kgyear, E

thres=5keV

He(NuclearRecoil),kgyear, E

thres=1meV

Geometric Cro

ss Section



Short Range Mediator10 MeV

Collider Constraints

100 103 106 109 1012 101510-42

10-39

10-36

10-33

10-30

10-27

10-24

10-21

10-18

10-15

10-12

MX (GeV)

σ Xn(cm2 )

mχ=10 MeV, Fmed = 1, 1% subcomp. DM

LiquidXe, 1.5*104kgyear, E

thres=5keV

XENON1T,98kgyear, E

thres=5keV

Semiconductor(Ge

), 100kgyear, E

thres=50

eV

CDMSLite, 0.2 kg year, E t

hres=0.5keV

Semicon

ductor

(Si), kg

year, E t

hres=10 meV

He(NuclearRecoil), kg year, E t

hres=1 meV

Geometric Cros

s Section

10-9

10-6

0.001

1

1000

106

gXgnMXμ XN/(M

Nm

ϕ2 )

(1/GeV

)



Long Range Mediator


Collective ExcitationsPolar Crystals

General Idea: Low momentum transfer excites phonon modes in crystal lattice

*Griffin et al, 1807.1029


Nuclear Recoil Long RangeEnhancement at Low Momentum

Recall: Scattering due to light mediator is enhanced at low momentum by 1/q4


Nuclear Recoil Long RangeEnhancement at Low Momentum

Recall: Scattering due to light mediator is enhanced at low momentum by 1/q4

Minimizing detector’s energy threshold is key


Long Range Mediator10 GeV

103 106 109 1012 101510-45

10-42

10-39

10-36

10-33

10-30

10-27

10-24

10-45

10-42

10-39

10-36

10-33

10-30

10-27

10-24

MX (GeV)

σ Xn(cm2 )

mχ=10 GeV, Fmed = q02/q2

LiquidXe, 1.5*10

4 kgyear,E thres=5keV

XENON1

T, 98 kg

year, E th

res=5 k

eV

GaAs (A

coustic

Mode), k

g year, E

thres=1

meV

Perturbativity



Long Range Mediator10 GeV

SIDM constraint

Perturbativity

In-medium effects

103 106 109 1012 101510-45

10-42

10-39

10-36

10-33

10-30

10-27

10-24

MX (GeV)

σ Xn(cm2 )

mχ=10 GeV, Fmed = q02/q2

LiquidXe, 1.5*10

4 kgyear,E thres=5 keV

XENON1

T, 98 kg

year, E thr

es=5keV

Semicon

ductor (G

e), 100 k

g year, E

thres=50 eV

CDMSLit

e, 0.2 kg

year, E thr

es=0.5 ke

V

Semicon

ductor (S

i), kgyear

, E thres=10 me

V He (Nuc

learRec

oil),kg y

ear,E thre

s=1meV

GaAs (A

coustic M

ode), kg

year, E thr

es=1meV

He (Pho

nons), kg

year, E thr

es=1meV

Perturbativity

10-12

10-9

10-6

gXgnMXμ XN/M

N(GeV

)



Extremely Long Range Mediator


Mediator Coupling ConstraintsDark Sector Constraints

* Akin to gravitational collapse

Scalar Coupling gx Bound: Stability of Dark Nuclei

• Fermi degeneracy pressure must balance self-energy due to long range attractive interaction*

• Additional repulsive interactions does not help as blobs become unbound

28


Λx = MeV, λ = 200 km

DMG, Melia and Rajendran ‘18

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General Idea: Passing DM induces motion in test mass

Acceleration

30

Free hanging test mass

DM

Test Mass



Acceleration

30


DMTest Mass

b

θ



Acceleration

30


• Example: LIGO sensitive to Δx ~ 0.1 fm/Hz1/2

DMTest Mass

b

θ


Tank: (500 m)3

Λx = MeV, λ = 200 km

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DMG, Melia and Rajendran ‘18



ConclusionsFocus: Detecting composite dark matter

Take Away: Strongly interacting dark sector can give DM whose mass ranges over 40 orders of magnitude

• Dark Nuclear Matter

• Dark Quark Matter (Not discussed here)

Take Away: Need multi-prong approach to span the full parameter space of masses and confinement scales

• Both existing and near future direct detection experiments are important

direct detection of composite dark matter...wimps, hidden sector, asymmetric, etc high number...

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