particle theory models and dark matter: a status...

1

Bhaskar DuttaTexas A&M University

Particle Theory Models and Dark Matter: A Status Update

October 31, 2017

Texas Tech University, Lubbock

2

QuestionsSome Outstanding Issues of High Energy Theory

1. Dark Matter content ( is 27%)

2. Electroweak Scale

3. Ordinary Matter (baryon) Content ( is 5%)

4. Rapid Expansion of the Early Universe

5. Neutrino Mass and interactions...

Need: Theory, Experiment and Observation

DMΩ

bΩ

3

Questions

4

Current Status

Collider Experiments: LHCDirect Detection Experiments: DAMA, CDMS, XENON 100,

CoGeNT, LUX etc.Indirect Detection Experiments: Fermi, AMS, PAMELACosmic Microwave Sky: Planck, WMAPNeutrino Experiments: T2K, Daya Bay, Double CHOOZ,

RENO etc. COHERENT

What have we learnt? What is the status of theory models? What do we expect in the near future?Are we closing in?

5

What have we learnt so far? LHC, Direct and Indirect Detection Experiments, Planck Data

Status of Models with DM Dark Matter: Cosmological History Dark Matter, Ordinary Matter Contents

Expectations Future Direct and Indirect Detection results Dark Matter at the LHC

Concluding Insights

Presentation Outline

6

Large Hadron Collider(LHC)

Proton-Proton Collision

7

Higgs Boson has been found Mass (mh) 125 GeVCompletes Standard Model

3 families of quarks, leptons, Gauge Bosons (force carriers) : W±, Z, γ, g

LHC: Higgs

Higgs mechanism breaks the SM symmetry spontaneously and generates mass for quarks, leptons, W, Z and Higgs

Symmetry breaking scale(Electroweak scale): 246 GeV

Much lower than the Planck scale: 1.22 x 1019 GeV

Mz=91.18 GeV, Mw=80.22 GeV

8

• Higgs mass increases rapidly with scale mh2= m0

2+k Λ2: divergence problem solution needs fine tuning (1 part in 1032)

• SM prediction: mh<850 GeV to satisfy the unitarity in W scattering

• Fine tuning problem solved in supersymmetry due to fermions ↔ bosons symmetry

• Higgs mass predicted in SUSY Model?Minimal Supersymmetry Standard Model (MSSM):

loop correction prediction: mh<135 GeV

•Measured mass (125 GeV) appears in the tight MSSM window

LHC: Higgs

+= β2222 CosMm Zh Mz=91.18 GeV

9

LHC: Supersymmetry

Most models predict: 1-3 TeV (colored particle masses)So far: No colored particle up to 1.9 TeV

Non-colored SUSY particles: 100 GeV to 1-2 TeV(Major role in the DM content of the Universe)

Weak LHC bound for non-colored particles hole in searches!

Trouble in Models with very tight correlation between colored and non-colored particles , e.g., minimal SUGRA/CMSSM

LHC + Direct Detection + Indirect Detection quite constraining

10

Direct Detection Experiments

Any parameter space left?

DM

DM

CDMS, DAMA, CoGeNT:Signal for Low mass DM

LUX: No signal for Low or High DM mass

arXiv:1608.07648

Status of New physics/SUSY in the direct detection experiments:

• Astrophysical and nuclear matrix element uncertainties• No signal: some particle physics models are ruled out

Indirect Detection: Fermi

11

: smaller than the thermal valueoannv ><σ

>< vannσ

Thermal DM 27%

Gamma-rays constraints: Dwarf spheroidals, Galactic center

Experimental constraints:

Fermi Collaboration: arXiv:1503.02641

LargeCross-sectionis constrained

12

From Planck

http://public.planck.fr/images/resultats/2014-matiere-noire/plot_constraints_planck2014.jpg

Indirect Detection Excess of positrons has been found by both

AMS, PAMELA and Fermi

13

Dark Matter Mass: More than 100 GeVTheory Models predictions: The excess will fall off

Pulsar can produce this excess

Is this excess due toDM annihilation?

Need Larger Cross-section (larger than the thermal cross-section 3x 10-26 cm3/sec)

14

Probing Dark Matter

SM

Dark Energy68%

Atoms5%

Dark Matter27% +

Collider experiments

Overlapping region

DM content (CMB) + overlapping region:

Cosmological history, particle physics models, astrophysics

Summary

Direct Production at the collider: SUSY lurking around? More Higgs? New signal?

Direct Detection and LHC: Low/high mass DM particle?

Indirect Detection and LHC: DM thermal/non-thermal/multi-component?

15

~ 0.0000001 seconds

Dark Matter: When?

16

Now

Dark Matter: ThermalProduction of thermal non-relativistic DM:

particlesSMDMDM ⇔+

particlesSMDMDM ⇒+

Universe cools (T<mDM)

particlesSMDMDM ⇔+

Boltzmann equation

][3 2,

2eqDMDMeqDM

DM nnvHndt

dn−−=+ σ

∫

∫+−

+−

=

6

/)(2

31

3

6

/)(2

31

3

)2(

)2(21

21

π

πσ

σ TEE

TEE

eq epdpd

vepdpd

vvolnostppfdgn /.

)2(),(

3

3

≡= ∫ π

m/T

3* Tgn

snY

s

==Y

Dark Matter: Thermal

Freeze-Out: Hubble expansion dominates over the interaction rate

18

v1~DM σρc

DMDM nm=Ω

20~ DM

fmT

Dark Matter content:

Assuming : 2

2

~vχ

χασmf

αχ~O(10-2) with mχ ~ O(100) GeVleads to the correct relic abundance

m/T

freeze out

scm3

26103v −×=σY becomes constant for T>Tf

Nc G

Hπ

ρ83 2

0=

Y

Y~10-11 for mχ~100 GeVto satisfy the DM content

Thermal Dark Matter

DM particle + DM Particle SM particles

Annihilation Cross-section Rate:

19

>< vannσ

DM

DM

DM

DM

f: SM particles; h, H, A: various Higgs, : SUSY particleNote: All the particles in the diagram are colorless

v1~DM σ

Ω

DM Abundance:

f~

scm3

26103v −×=σWe need to satisfy thermal DM requirement

20

Suitable DM Candidate: Weakly Interacting Massive Particle (WIMP)

Typical in Physics beyond the SM (LSP, LKP, …)

Most Common: Neutralino (SUSY Models)

Neutralino: Mixture of Wino, Higgsino and Bino

Neutralino can give rise to larger/smaller annihilation rate

Larger/Smaller Annihilation Non-thermal Models

Thermal Dark Matter

Thermal Dark Matter

Dark Energy68%

Atoms5%

Dark Matter27%

v1~DM σ

Ω

20~ DM

fmT

Dark Matter content:

Weak scale physics :

2

2

~vχ

χασmf

αχ~O(10-2) with mχ ~ O(100) GeVleads to the correct relic abundance

freeze out

scm3

26103v −×=σ

Mp

Inflation

TeV

GeV

MeVBBN

~ WIMP freeze-out

Non-standard thermal history at is generic in some explicit high Scale theories.

fTfTT >

Acharya, Kumar, Bobkov, Kane, Shao’08Acharya, Kane, Watson, Kumar’09Allahverdi, Cicoli, Dutta, Sinha,’13

Status of Thermal DMThermal equilibrium above is an assumption.

DM content will be different in non-standard thermal histories Barrow’82, Kamionkowski, Turner’90

DM will be a strong probe of the thermal history after it is discovered and a model is established.

23

Non-Thermal DM

Decay of moduli/heavy field occurs at:

)MeV5(TeV100

~2/3

2/1

φmcTr

Tr ~ MeV : Not allowed by BBN

[Moduli : heavy scalar fields gravitationally coupled to matter]

>< vannσ : different from thermal average, is not 27% Non-thermal DM can be a solution

DM from the decay of heavy scalar field, e.g., Moduli decay

For Tr<Tf: Non-thermal dark matter

v1~DM σ

Ω

Decay of moduli produce both DM and ordinary matter

Moroi, Randall’99; Acharya, Kane, Watson’08,Randall; Kitano, Murayama, Ratz’08; Dutta, Leblond, Sinha’09; Allahverdi, Cicoli, Dutta, Sinha,’13Baer, Choi, Kim, Roszkowski’ 14 Mp

Inflatio

TeV

GeV

MeV

24

Non-thermal DM

Non-thermal DM Production from moduli decay

Ordinary Matter and DM from moduli decay ⇒ Cladogenesis of DM and Ordinary Matter (Baryons) [Allaverdi, Dutta, Sinha’11]

Cladogenesis: is an evolutionary splitting event in a species in which each branch and its smaller branches forms a "clade", an evolutionary mechanism and a process of adaptive evolution that leads to the development of a greater variety of sister species.

25

Mp

Inflation

TeV

GeV

MeVBBN

~ WIMP freeze-out

Mp

Inflation

TeV

GeV

MeVBBN

Non-thermal DM

Large multicomponent/non-thermal; Small Non-thermal

Probe directly at Indirect and Collider experiments

>< vannσ

DM content: summary

>< vannσ

26

Future: Direct

Neutrino background seems to be a real problem!

27

Neutrino background difficulties:

1. Measure the background very well in other experiments2. Measure the recoil spectrum to identify DM from neutrino

Future: Direct

1. Background is due to coherent scattering of solar and atmospheric neutrinos

Measure the coherent scattering: reactor (𝝂𝝂𝒆𝒆) and stopped pion sources (𝝂𝝂𝝁𝝁,𝝂𝝂𝝁𝝁, 𝝂𝝂𝒆𝒆)

Recent results: COHERENT (Science 03 Aug 2017)Future results: Miner, MINER+CONNIE : Texas A&M University

Determine the neutrino background carefully

2. Shape of the recoil spectra are different for different operators Identify neutrino from DM

Dent, Dutta, Newstead, Strigari, Walker, 2016

28

Future: Indirect

DM+DM 𝑓𝑓 + 𝒇𝒇 𝟐𝟐𝑓𝑓 + 𝟐𝟐𝒇𝒇

b quark final states have the best constraints

Clark, Dutta, Strigari, arXiv:1709.07410

<σv>

cm

3 /s

MDM (GeV)

29

Dark Matter at the LHC

Annihilation of lightest neutralinos (DM particles) quarks, leptons etc.At the LHC: proton + proton DM particles

DM Annihilation diagrams: mostly non-colored particlese.g., sleptons, staus, charginos, neutralinos, etc.

How do we produce these non-colored particles and the DM particle at the LHC? Can we measure the annihilation cross-section ?>< vannσ

30

The signal : SM particles + DM particle(Missing energy)

Via Cascade decays at the LHC

(or l+l-, τ+τ−)DM

DMColored particles are produced and they decay finally into the weakly interacting stable particle

High PT jet

(or l+l-, τ+τ−)LHC is very complicated

DM at the LHC

31

LHC has a blind spot for productions of non-colored particle

Special search strategy needed to extract the signal

The W boson (colorless) coming out of high energy protons can produce colorless particlesVector Boson Fusion(VBF)

New way of understanding DM or new physicssector at the LHC

Using a high ET jet + missing energy

Dutta, Gurrola, Kamon et al ’13,’14,’15,’16

32

Cross Sections via VBFDM Via W at the LHCjjpp 0

10

1~~ χχ→

DM

33

DM Content via VBF

Simultaneous fit of various observables:

How to check that LHC observations lead to correct dark matter content? Measure Ω at the LHC (Ω is 27%: Planck Measurement)

Dutta, Kamon etal, Phys.Rev.Lett. 111 (2013) 061801

34

DM via jets +missing energy

CMS PAS EXO-16-048

Kunori et al

35

Concluding InsightsModel ideas have constraints from LHC, Planck,

Neutrino data, direct and indirect detection constraints Higgs mass is within the supersymmetry model prediction

window Non-thermal Dark matter is well motivated Both Thermal and Non-thermal Dark matter have

allowed parameter spaceNon-thermal scenarios can allow us to understand the

Ordinary Matter-Dark Matter coincidence puzzleDetermination of the property of DM is crucial: LHC, direct and Indirect detections identify DM modelNeed to investigate colorless particles (suitable for DM

calculation), new force mediators at the LHC and in other experiments (e.g., Coherent neutrino scattering)

36

Concluding Insights