[PPT] - Phase Transitions, Gravitational Waves, and Composite Dark Matter PowerPoint Presentation

SLIDE 1

Phase Transitions, Gravitational Waves, and Composite Dark Matter

Pedro Schwaller (DESY)

Lattice for BSM Physics 2016 Argonne National Laboratory April 22, 2016

SLIDE 2

Outline

DM from confining SU(N)
First order Phase Transitions
PT dynamics from lattice?
Gravitational Waves from FOPT
Detection - Ground, Space, PTA

2

SLIDE 3

Composite DM

Alternative to elementary WIMP models
Phenomenologically viable, “generic” possibility in

presence of hidden sectors

Some nice features:
DM stability, mass scale
Symmetric component annihilation for ADM
Self-interactions

3

SLIDE 4

Dark QCD

Models I’m interested in here
Nonabelian SU(N) dark sector, confinement scale
light/massless flavours

4

Λd nf

nf = 0 nf > 0

Glueball DM 

PT from center symmetry restoration Dark Baryons 

r Dark Pions

Chiral Symmetry Breaking

SLIDE 5

The Dark Phase Transition

SLIDE 6

Phase Transition

SU(N) dark sectors well motivated
Confinement/chiral symmetry breaking phase

transition at scale

DM: (MeV - 100 TeV)
Naturalness:
First order PT in large class of models
Still possible if LHC finds no new physics

6

Λd Λd ∼ MDM Λd ∼ few × ΛQCD

SLIDE 7

QCD Phase Diagram

7

Strong First Order Strong First Order SM W e a k C r

s

s

v

e r

mu,d

ms

SLIDE 8

Phase Diagram II

8

Strong First Order Strong First Order SM W e a k C r

s

s

v

e r

mu,d

ms

Fraternal Twin Higgs Dark QCD SIMP models Glueball DM

SLIDE 9

SU(N) - PT

Consider with massless flavours
PT is first order for
,
,
Not for:
(no global symmetry, no PT)
(not yet known)

9

SU(Nd) nf Nd ≥ 3 nf = 0

Svetitsky, Yaffe, 1982

M. Panero, 2009

Nd ≥ 3 3 ≤ nf < 4Nd

Pisarski, Wilczek, 1983

nf = 1 nf = 2

SLIDE 10

SU(N) - PT 2

One more parameter: angle
Effect on PT not well studied
dependence of PT strength?
Finite density/chemical potentials?
QCD FOPT?
GW signal:

10

Θ

M. Anber, 2013

Garcia-Garcia, Lasenby, March-Russell, 2015

Nd, nf

Panero, 2009 Schwarz, Stuke, 2009 Caprini, Durrer, Siemens, 2009

10 4 0.01 1 100 104

22 19 10−10 10−8 10−6 10−4 10−2 10−15 10−10 10−5 100

f [Hz] h2 Ω(f)

Current NANOGrav sensitivity PTA 2020 LISA

SLIDE 11

Questions for Lattice

Dynamics of PT known from lattice?
Latent heat
Bubble nucleation rate
Dependence on
theta param, chem. potentials?
At least some of this is known AFAIK
For Cosmology: relevant

11

Nd, nf T < TC

I’d be happy to collaborate!

SLIDE 12

Gravitational Wave spectra from FOPT

SLIDE 13

Cosmological Phase Transitions

Early Universe in symmetric phase (e.g. unbroken

electroweak symmetry)

13

T > Tc T < Tc T < Tc

Second 

rder

First 

rder

SLIDE 14

GWs from PTs

14

First order PT ➞ Bubbles nucleate, expand Bubble collisions ➞ Gravitational Waves

SLIDE 15

Signal is Universal

PT characterised by few parameters:
Latent heat 
Bubble wall velocity
Bubble nucleation rate
PT temperature
Three physical contributions
Bubble wall collisions
Turbulence
Sound waves

15

Extensive numerical

simulations. Recently e.g.

Hindmarsh et al: Sound wave contributions

Phenomenological Parameterisations: Caprini et al, 1512.06239

α ≈ Ωvacuum Ωrad

v β T∗

SLIDE 16

GW signal

16

10-8 10-7 10-6 10-5 10-4 0.001 0.010 10-12 10-10 10-8 10-6 f [Hz] h2ΩGW

Bubble Collisions Turbulence

* p r

b

a b l y s m a l l e r

SLIDE 17

Peak Frequency

Redshift:
Peak regions:

17

f = a∗ a0 H∗ f∗ H∗ = 1.59 ⇥ 10−7 Hz ⇥ ⇣ g∗ 80 ⌘ 1

6 ⇥

✓ T∗ 1 GeV ◆ ⇥ f∗ H∗ q

k/β ≈ (1 − 10) H f(B)

peak = 3.33 ⇥ 10−8 Hz ⇥

⇣ g∗ 80 ⌘ 1

6

✓ T∗ 1 GeV ◆ ✓ β H∗ ◆

PT Temperature ~ DM Mass

SLIDE 18

Experiments

18

IPTA SKA eLISA old eLISA best case BBO LIGO 2016 LIGO 2022 EPTA NANOGrav

10-9 10-7 10-5 0.001 0.100 10 10-13 10-10 10-7 10-4 10-1 f [Hz] ΩGWh2

Satellite based eLISA: 2028/2032 Pulsar timing arrays Data already available Ground based

*

* From A. Petiteau

SLIDE 19

19

SIMP Composite ADM Twin Higgs Composite WIMP-y DM Unitarity

IPTA LISA ALIA DECIGO BBO EPTA ELISA T* = 0.1 GeV T* = 3 G e V T* = 300 GeV T* = 10 TeV SKA

10-10 10-8 10-6 10-4 0.01 1 10-15 10-13 10-11 10-9 10-7 10-5 0.001 f @HzD h2WGW

B-L breaking, Hidden Sectors LIGO

SLIDE 20

Summary

Symmetry breaking with first order PT ➞

Gravitational Waves!

Signal from composite DM sector could be
bservable
Interesting tasks for numerical (lattice) simulations
PT dynamics for strongly coupled models
PT non-perturbative sometimes even for weakly coupled

models

Simulation of GW signal from PT

20

SLIDE 21

21

SLIDE 22

GWs as window to dark matter sector

Motivation for (non-abelian) Dark Sectors
Phase Transition of SU(N) Theories
GW Signals from PTRs to ELISA

22

Based on PRL 115 (2015) 18, 181101

SLIDE 23

Dark Matter

23

We#have#seen#DM#in#the#sky:# But#no#direct#observa7on##

mWIMP (GeV/c2) 10 1 10 2 10 3 10 −45 10 −44 6 8 10 12 10 −44 10 −42 10 −40

LUX#

Maybe#DM#is#just#part#of#a#larger#dark#sector##

Example:#Proton#is#massive,#stable,#composite#state#
DM#self#interac7ons#solve#structure#forma7on#problems#
New#signals,#new#search#strategies!#

SLIDE 24

Composite DM

24

GeV TeV

asymmetry sharing annihilation

Xd pD , . . . πD , . . . QCD dark QCD π , K , . . . p , n

decay

SU(N) dark sector

with neutral   “dark quarks”

Confinement scale
DM is composite

“dark proton”

ΛdarkQCD

Bai, PS, PRD 89, 2014 PS, Stolarski, Weiler, JHEP 2015 many other works! Similar setup e.g.: Blennow et al; Cohen et al; Frandsen et al; Reviews: Petraki & Volkas, 2013; Zurek, 2013;

SLIDE 25

DM Motivation

New mechanisms for relic density, extend mass range:
Asymmetric DM - GeV-TeV scale
Strong Annihilation - 100 TeV scale
SIMP - MeV scale
Advantages of Composite
DM mass scale and stability
Fast annihilation for ADM
Self-interactions for structure formation

25

Hochberg, Kuflik, Volansky, Wacker, 2014; + Murayama, 2015

SLIDE 26

GW spectra

Lot of work on GW from 1st order PT
Still difficult to simulate or model
Here in addition:
Transition is non-perturbative
Parameters not known - take an optimistic guess

26

β/H∗ = 1 − 100 v = 1 κα 1 + α = 0.1

See talks by Hindmarsh, Weir for more details