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EW Multiplet DM at the FCC-hh

4th FCC Physics and Experiments Workshop, CERN November 11, 2020

M.J. Ramsey-Musolf •  T.D. Lee Institute &

Shanghai Jiao Tong Univ. •  UMass-Amherst

My pronouns: he/him/his

•  mjrm@sjtu.edu.cn •  微信 ： mjrm-china

Collaborators: •  Cheng-Wei Chiang •  Giovanna Cottin •  Yong Du [1] •  Kaori Fuyuto

•  Nicole Bell •  Matthew Dolan •  Leon Friedrich [2] •  Raymond Volkas

[1] UMass Amherst [2] U Melbourne

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References

•  2001.05335: N. Bell, M. Dolan, L. Friedrich, MJRM, R. Volkas

•  2003.07867: C.-W. Chiang, G. Cottin, Y. Du, K. Fuyuto, MJRM

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Key Ideas for this Talk

•  EW Multiplet DM is in interesting target for the LHC and prospective future colliders

•  Disappearing charged track searches provide a particularly powerful probe

•  There exists the potential for a high degree of complementarity with direct detection experiments

•  The FCC-hh sensitivity depends strongly on pile-up issues ! important challenge for future experimental development

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Outline

I.  Context & Questions

II.  The Real Triplet Extension

III.  Collider & DM Phenomenology

IV.  Outlook

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I. Context & Questions

•  Are there any DM scenarios that the LHC and future colliders can test definitively ?

•  For what fraction of the DM relic density are collider searches sensitive in these scenarios ?

Dark Matter

6 Thanks: Z. Liu, T. Lin

Dark Matter

7 Thanks: Z. Liu, T. Lin

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EWPT & Dark Sector: EW Multiplets Cirelli & Strumia ‘05

Real Triplet

“Minimal Scalar DM”

Higgsino

Wino Triplet

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EWPT & Dark Sector: EW Multiplets Cirelli & Strumia ‘05

Real Triplet

“Minimal Scalar DM”

Higgsino

Wino Triplet

Signature: Disappearing charge track S+ ! SDM + π+ (soft)

WIMP Dark Matter Probes

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Disappearing Charged Track

DM Interactions

χ0SM

SM

χ+

X X = j, V, h

χ0

π+

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Dark Sector: EW Multiplets Mono-jet, DCT, Mono-Z J.F. Zurita

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Dark Sector EW Multiplets @ FCC-hh

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II. Real Triplet Scalar Extension: ΣSM

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The ΣSM

Σ ~ (1, 3, 0)

DM and collider pheno set by EW gauge interactions (fixed by rep) and Higgs portal:

Higgs portal interaction: not widely considered in earlier work

Mass Spectrum

Small mass splitting due to EW radiative corrections

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For mΣ >> mZ ! Δ mΣ = 166 MeV

Decays

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Σ+ ! Σ0 + soft

Signature: Disappearing charged track

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III. ΣSM: Collider & DM Phenomenology

DCT: Real Triplet DM (2008) Basic signature: Charged track disappearing after ~ 5 cm

SM Background: QCD jZ and jW w/ Z !νν & W!lν

Trigger: Monojet (ISR) + large ET

Cuts: large ET hard jet One 5cm track

Fileviez Perez, Patel, MRM, Wang ‘08

DCT: Real Triplet DM @ LHC (2008) Basic signature: Charged track disappearing after ~ 5 cm

SM Background: QCD jZ and jW w/ Z !νν & W!lν

Trigger: Monojet (ISR) + large ET

Cuts: large ET hard jet One 5cm track

Cirelli et al:

MΣ = 500 GeV:

ΩΣ / ΩCDM ~ 0.1

Fileviez Perez, Patel, MRM, Wang ‘08

ATLAS DCT Limits: SUSY (AMSB)

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χ+ ! χ0 + soft

1712.02118

ATLAS DCT Limits: Recast

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•  2001.05335: Simple extrapolation based on cross sections

•  2003.07867: Detailed validation using AMSB model & efficiency map

ATLAS DCT Limits: Recast

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•  2001.05335: Simple extrapolation based on cross sections

mΣ > 250 GeV

ATLAS DCT Limits: Recast

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•  2003.07867: Detailed validation using AMSB model & efficiency map

•  Trigger: ISR jet

•  Selection: pTmiss > 140 GeV, no electrons

or muons, pT and Δφ requirements

•  Tracklet selection

ATLAS DCT Limits: Recast

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•  2003.07867: Detailed validation using AMSB model & efficiency map

pT > 100 GeV

Project to HL LHC & FCC-hh

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•  Employ our real triplet UFO model for event generation

•  Includes Higgs portal interaction (coupling a2 )

•  HL-LHC: statistics

•  FCC-hh: follow 1901.02987 (a) rescale selection requirements (b) include pile-up scenarios ; retain ATLAS tracklet requirements

Project to HL LHC & FCC-hh

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•  Impact of Higgs portal coupling: low mΣ

Current LHC Limit & HL-LHC Projection

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* Assumes Δ mΣ = 160 MeV

Current*: mΣ > 275 GeV

HL-LHC*: mΣ > 520 GeV

FCC- hh Projection

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Pile up scenarios

Reach depends significantly on pile up effects

Real Triplet DM: ΩDM

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Real Triplet DM: ΩDM & Colliders

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ΩΣ / ΩDM

Bound state

Red: LHC Black: FCC-hh

•  Significant correlation: a2 , mΣ , ΩΣ

•  FCC-hh exclusion: ΩΣ / ΩDM =1 for a2 = 0 (optimistic pile-up) ; successively smaller fraction for larger | a2 |

Real Triplet DM: Direct Detection & Colliders

31 Red: LHC Black: FCC-hh

•  Significant correlation: a2 , mΣ , direct detection limits

•  FCC-hh exclusion: can

fill XENON 20t “blind spot” or correlate observations for mΣ < 3 TeV (optimistic pile up scenario)

XENON 1t excl (2018)

XENON 20t proj. excl.

IV. Outlook

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•  EW Multiplet DM is in interesting target for the LHC and prospective future colliders

•  Disappearing charged track searches provide a particularly powerful probe

•  There exists the potential for a high degree of complementarity with direct detection experiments

•  The FCC-hh sensitivity depends strongly on pile-up issues ! important challenge for future experimental development

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Back Up Slides

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EWPT & Dark Sector: EW Multiplets

λeff = 5

λeff = 0

λeff = 2

No co-annihilation No Sommerfeld

EWPT

Saturate ΩDM

W. Chao, G.-J. Ding, X.-G. He, MJRM 1812.07829

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EW Multiplet DM: Direct Detection

Nuc

Nuc

h

χ0

χ0

λeff

Nuc

Nuc

W

W

χ0

χ0

Gauge interactions Higgs portal interactions

W. Chao, G.-J. Ding, X.-G. He, MJRM 1812.07829

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EW Multiplet DM: Direct Detection

λeff = 1 allowed

W. Chao, G.-J. Ding, X.-G. He, MJRM 1812.07829

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EW Multiplet DM: Direct Detection

λeff = 1 allowed

EWPT favored

W. Chao, G.-J. Ding, X.-G. He, MJRM 1812.07829