1. Dark Sectors at High Energy Colliders
Yuri Gershtein
David Shih
Scott Thomas

2. Standard Model Portals:
Dark Sector
Messenger Interactions
Portals - (Local Operators)
Standard Model Portals:
D= B  , H* H
D=5/2 LH
D= Q*  Q , L  L , 
D= QHu , G  G  , H* W  H ,  
Dark sector = kinematically accessible but uncharged under SM gauge interactions ……

3. Portals Into and Out of the Dark Sector
Standard Model
Dark Sector
Portals Into and Out of the Dark Sector
Standard Model  Dark Sector  Standard Model
Can arise in many frameworks – SUSY breaking extra very light states (Goldstino) …..
Strassler has stressed ….. Rather generic …. Hidden Valley framwork Neal and Nima in the context of Dark sector models designed to give Sommerfeld generic ……

4. Dark Sector Production at High Energy Colliders
Indirect Production with Shared Conserved Quantum Number
Direct Production
Indirect Production 2 2
Low Energy experiments : Direct Production only (or through virtual SM state)
Standard Model
Standard Model
Dark Sector
Standard Model
Dark Sector
Dark Sector
 » O(2)
Br » O(2)
 ¢ Br » O(0)
Which Dark Sector States Populated – Depends on Production Portals
Portal » 

5. Dark Sector Production at High Energy Colliders
Indirect Production with Shared Conserved Quantum Number
Direct Production
Indirect Production
Resonant Dark DY
Higgs, Z Decay
SUSY + R-Parity 2 2
Low Energy experiments : Direct Production only (or through virtual SM state)
Standard Model
Standard Model
Dark Sector
Standard Model
Dark Sector
Dark Sector
 » O(2)
Br » O(2)
 ¢ Br » O(0)
Which Dark Sector States Populated – Depends on Production Portals
Portal » 

6. Dark Sector Decay to Standard Model
If No Dark Decay Mode Open – Dark Sector State Can Decay Back to Standard Model Through Portals
Guaranteed for LDSP if no Conserved Quantum # 2
Standard Model
Dark Sector
All, Some, or None of the Dark Sector States May Have Prompt Decays Back to the Standard Model
Very Wide Range of Possibilities Depending On:
Production Portal
Dark Spectrum
Dark Cascade Decays
Dark Showering
Decay Portal

7. Dark Sector Decay to Standard Model
Classify Dark Decay Modes According to Relevant Experimental Considerations:
Standard Model
Dark
Dark Object Content ¾ {Leptons, Jets, MET} –
Decay Portals (No Decay = MET)
2. Dark Object Multiplicity / Isolation -
Dark Cascades and/or Dark Showering (Confined Non-Abelian or Higgsed (Non)-Abelian Large gD)
High Multiplicity Low Multiplicity
Non-Isolated Object Isolated Object
At one extreme …..
For Theorists - in working groups – might be best to define signatures in terms of these Considerations …..
Rather than universal definition of a lepton jet with isolation, etc. -- the experimentalists can figure out isolation, etc. once given specific signature ……
( “Lepton Jets” ) ( Di-muons ) “Difficult” “Easy” *
3. Associated Objects from Production/Decay – {Leptons, Jets, MET}

8. Dark Sector ¾ Abelian Gauge Symmetry
Standard Model Portals Dark Sector Portals
D= B  , H*H X  , HD*HD
D >  
Marginal SM - Dark Interactions :
Photon - Dark Photon - Z Boson Mixing
Higgs - Dark Higgs Mixing

9. Higgsed Abelian Dark Sector - Decay to Standard Model2
Standard Model
Dark Sector
Leading Decay Portals:

10. Higgsed Abelian Dark Sector - Decay to Standard Model
Dark Photon Decay
Prompt
Dark Photon Branching Ratio
Hadrons + Leptons

11. Higgsed Abelian Dark Sector - Decay to Standard Model
Dark Higgs Decay
Spectator model - could be improved ……

12. Higgsed Abelian Dark Sector - Decay to Standard Model
Dark Higgs Decay
This decay has been mentioned by the SLAC group and I think the Princeton group
Note decay with two off-shell dark photons is too slow …. Summarize
Most of the D* Goes Through Hadronic Resonances

13. Higgsed Abelian Dark Sector - Direct Production2
Standard Model
Dark Sector
Leading Direct Production Portals:
O(3/2) ¢ mX/ vSM

14. Higgsed Abelian Dark Sector - Direct Production
Direct Dark Photon Production
Assume D  SM : Resonance Search in + - DY (Background – Data)
Tevatron Sensitivity for m » few GeV  » 10-3

15. Higgsed Abelian Dark Sector - Indirect Production2
Standard Model
Dark Sector
Leading Indirect Production Portals  Two Universal Dark Portals
(Focus on These Portals )

16. Higgsed Abelian Dark Sector - Indirect Production
Z Boson  Dark Higgs + Dark Photon
Assume D  SM :
Inclusive Isolated l+ l- + + - Resonance Search in Z Decays
LEP: O(107) Z’s Ell,   ' mZ/ (Veto l+l- )
Tevatron: O(106) Z’s
LHC: …

17. Higgsed Abelian Dark Sector - Indirect Production
Higgs Boson  Dark Photon + Dark Photon
Assume D  SM :
High pT Isolated ( l+ l- )(l+ l-) + (l+ l-)(+ -) ? Di-Resonance Search
Tevatron: h  (+ -)(+ -) Search
LHC: h  ( l+ l- )(l+ l-) + (l+ l-)(+ -) ? Search (c.f. h   )
For mh ' 120 GeV ’ ' 

18. Higgsed Abelian Dark Sector - Indirect Production
Higgsed Abelian Dark Sector - Indirect Production With Shared Conserved Quantum Number 2
Standard Model
Dark Sector
Supersymmetry with Conserved R-Parity

19. SUSY Dark Sector ¾ SUSY Abelian Gauge Symmetry
Standard Model Portals Dark Sector Portals
D=3/ B D
D= B  , H*H X  , HD*HD
D=5/  * D D* 
Leading Indirect Production Portal  Universal Dark Portal
B D GD
(Focus on This Portal)

20. Higgsed Abelian Dark Sector - Indirect Production
Higgsed Abelian Dark Sector - Indirect Production With Shared Conserved Quantum Number
Bino  Darkino + Dark Photon
Assume D  SM , D  Blocked :
Inclusive High pT Isolated ( l+ l- )(l+ l-) + (l+ l-)(+ -) ? Di-Resonance Search in Association with MET
Inclusive High pT Isolated ( l+ l- )(l+ l- *) + (l+ l-)(+ - * ) ?
Di-Resonance Search in Association with MET
See Yuri’s talk
Assume D , hD , D , D  SM + MET
Dark Object Search in Association with SUSY Cascade (Non-Isolated MET) 

21. SM Singlet + Higgsed Abelian Dark Sector - Indirect
SM Singlet + Higgsed Abelian Dark Sector - Indirect Production With Shared Conserved Quantum Number
Standard Model Portals Dark Sector Portals
D=3/ B , S D
D= B  , H*H X  , HD*HD
D=5/  * D D*
D=7/ S   F  D   X  
Leading Indirect Production Portal  Dark Portal
S D   X 
S   F  D

22. SM Singlet + Higgsed Abelian Dark Sector - Indirect
SM Singlet + Higgsed Abelian Dark Sector - Indirect Production With Shared Conserved Quantum Number
Singletino  Darkino + Photon , Dark Photon
Assume D  SM , D Blocked :
Inclusive High pT Isolated ( l+ l- )  + (+ -)  ? Resonance Search in Association with MET 

23. Di-Lepton Resonance Spin + Polarization
Goldstone Portals Longitudinal
Transition Dipole Portals – Transverse

24. Dark Sectors at High Energy Colliders
Three production Mechanisms Available
Direct Indirect Indirect with Quantum Number
Very Wide Range of Signatures … (Examples)
Dark Object Content {Jets, Leptons, MET} Dark Object Multiplicity / Isolation Associated Objects {Jets, Leptons, MET}
Dark Sector ¾ Higgsed Abelian Gauged Symmetry
Universal Portals  High pT Low Multiplicity Isolated Objects (In Association with Other Objects)
Di-Lepton Resonance - Spin + Polarization *