Dark Sectors at High Energy Colliders
Yuri Gershtein
David Shih
Scott Thomas
Standard
. Model
Dark
Sector
Messenger Interactions
Portals - (Local Operators)
Standard Model Portals:
D=2
B  , H* H
D=5/2
LH
D=3
Q*   Q , L   L , 
D=4
QHu , G  G  , H* W  H , 

Standard
. Model
Dark
Sector
Portals Into and Out of the Dark Sector
Standard Model  Dark Sector  Standard Model
Dark Sector Production at High Energy Colliders
Direct Production
Indirect Production
Indirect Production
with Shared Conserved
. Quantum Number
2
2
Standard
. Model
Dark
Sector
 » O(2)
Standard
. Model
Dark
Sector
Br » O(2)
Which Dark Sector States Populated –
Depends on Production Portals
Standard
. Model
Dark
Sector
 ¢ Br » O(0)
Portal » 
Dark Sector Production at High Energy Colliders
Direct Production
Indirect Production
Resonant Dark DY
Higgs, Z Decay
Indirect Production
with Shared Conserved
. Quantum Number
SUSY + R-Parity
2
2
Standard
. Model
Dark
Sector
 » O(2)
Standard
. Model
Dark
Sector
Br » O(2)
Which Dark Sector States Populated –
Depends on Production Portals
Standard
. Model
Dark
Sector
 ¢ Br » O(0)
Portal » 
Dark Sector Decay to Standard Model
If No Dark Decay Mode Open – Dark Sector State
Can Decay Back to Standard Model Through Portals
2
Standard
. Model
Dark
Sector
Guaranteed for LDSP if no Conserved Quantum #
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
Dark Sector Decay to Standard Model
Classify Dark Decay Modes According to
Relevant Experimental Considerations:
Dark
Standard
Model
1. 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
Non-Isolated Object
( “Lepton Jets” )
. “Difficult”
Low Multiplicity
Isolated Object
( Di-muons )
“Easy”
* 3. Associated Objects from Production/Decay – {Leptons, Jets, MET}
Dark Sector ¾ Abelian Gauge Symmetry
Standard Model Portals
D=2
D>2
Dark Sector Portals
B  , H*H
X  , HD*HD

Marginal SM - Dark Interactions

:
Photon - Dark Photon - Z Boson Mixing
Higgs - Dark Higgs Mixing
Higgsed Abelian Dark Sector - Decay to Standard Model
2
Standard
. Model
Dark
Sector
Leading Decay Portals:
Higgsed Abelian Dark Sector - Decay to Standard Model
Dark Photon Decay
Prompt
Dark Photon Branching Ratio
Hadrons + Leptons
Higgsed Abelian Dark Sector - Decay to Standard Model
Dark Higgs Decay
Higgsed Abelian Dark Sector - Decay to Standard Model
Dark Higgs Decay
Most of the D* Goes
Through Hadronic Resonances
Higgsed Abelian Dark Sector - Direct Production
2
Standard
. Model
Dark
Sector
Leading Direct Production Portals:
O(3/2) ¢ mX/ vSM
Higgsed Abelian Dark Sector - Direct Production
Direct Dark Photon Production
Assume D  SM : Resonance Search in + - DY
Tevatron Sensitivity for m » few GeV
 » 10-3
(Background – Data)
Higgsed Abelian Dark Sector - Indirect Production
2
Standard
. Model
Dark
Sector
Leading Indirect Production Portals  Two Universal Dark Portals
(Focus on These Portals )
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
Tevatron: O(106) Z’s
LHC:
…
Ell,   ' mZ/2
(Veto l+l- )
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
For mh ' 120 GeV
’ ' 
(c.f. h   )
Higgsed Abelian Dark Sector - Indirect Production
. With Shared Conserved Quantum Number
2
Standard
. Model
Dark
Sector
Supersymmetry with Conserved R-Parity
SUSY Dark Sector ¾ SUSY Abelian Gauge Symmetry
Standard Model Portals
Dark Sector Portals
D=3/2
B
D
D=2
B  , H*H
X  , HD*HD
D=5/2
 *
D D*

Leading Indirect Production Portal  Universal Dark Portal
B
D GD
(Focus on This Portal)
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
Assume D , hD , D , D  SM + MET
Dark Object Search in Association with SUSY Cascade
. (Non-Isolated MET)

SM Singlet + Higgsed Abelian Dark Sector - Indirect
. Production With Shared Conserved Quantum Number
Standard Model Portals
Dark Sector Portals
D=3/2
B , S
D
D=2
B  , H*H
X  , HD*HD
D=5/2
 *
D D*
D=7/2
S   F 
D   X 

Leading Indirect Production Portal  Dark Portal
S
D   X 
S   F 
D
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

Di-Lepton Resonance Spin + Polarization
Goldstone Portals
- Longitudinal
Transition Dipole Portals – Transverse
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