Dark Matter at colliders · 2019. 6. 4. · Benchmarks of choice 16 • Large number of model...

Dark Matter at colliders (continuing from M. McCullough’s talk)

CATERINA DOGLIONI - LUND UNIVERSITY

1

Code, inputs and discussion for summary plots: PPG BSM, PPG DM,PPG Higgs, ATLAS Collaboration,

Jean-Jacques Blaising, Antonio Boveia, Oleg Brandt, Ulrich Haisch, Phil C. Harris, Isabelle John, Matt McCullough, Jocelyn Monroe,

Hideki Okawa, Marco Rimoldi, Ulrike Schnoor, Emma Tolley, Francesca Ungaro, Andrea Wulzer

Caterina Doglioni - 2019/05/13 - European Strategy Update

Introduction Higgs portal Comparison to direct detectionBSM scalar mediator

Outline

2

General motivations for DM@(future) colliders, experimentalist’s perspective Signatures of dark matter at colliders Choice of benchmarks, benchmarks of choice:

• Higgs decays to invisible particles • Direct searches • Indirect determination of BR: fits

• Generic scalar mediators • Hadron colliders • Lepton colliders

• Contextualization of results • Benchmark models and relic density • Comparison of future colliders and direct detection

Some experimental considerations highlighted throughout the talk



Motivation for DM@colliders

3

How do we search for DM at colliders, depending on its properties?

• Generally assume some properties for the DM particle • interacts with SM particles → we can produce it at colliders

• [a matter of preference] is a thermal relic → WIMP • dark, stable → invisible to detectors

Caveat: very simplified diagram

known particle collision production of DM particles



Motivation for DM@colliders

4

visible

1^2P,

t> Z X

P XInvisible

Signature of invisible particles(like Dark Matter):

missing (transverse) momentum ( )

How do we search for DM at colliders, depending on its properties?



Searches for DM @ colliders

5

Production of invisible particles is common in the SM:

backgrounds need precise estimation

Process of interest: invisible (DM) particles

produced in association with radiated recoiling SM particle

DM

DM

e/q

e/q DM

g/ɣ

g/ɣe/q

e/q

input from theory/precision machines

X

example DM process



[GeV] γ E0 50 100 150 200

Eve

nts/

4 [G

eV]

10

210

310

410

510

610

710 -1L=1000 fb∫10 GeV, 〉γ

, E°170〈γθ〈°=380 GeV, 10s

γ ν ν → -e+B1:eγ -e+ e→ -e+B2:e

=120 GeVχ∼

, mγ 1χ∼

1χ∼ → -e+S:e

Searches for DM @ lepton colliders

6

DM

DM

e

e DM

ɣ

ɣe

e

+ other backgrounds, e.g. W t-channel…

J. J. Blaising, CLICdp

X



Searches for DM @ hadron colliders

7

DM

DM

q

q DM

g/V

g/Vq

q

+ other backgrounds, e.g. W, top

arXiv:1509.02904

X

https://arxiv.org/pdf/1509.02904.pdf



Searches for DM @ hadron colliders - with heavy quarks

8

More sophisticated searches when using other objects to

discriminate signal/background e.g. stransverse mass MT2for semi-invisible decays

arXiv:1902.10229 and ATL-PHYS-PUB-2018-036

Visible decays of the mediator relevant in all cases

(see M. McCullough’s talk)

https://cds.cern.ch/record/2651134/files/1902.10229.pdf



Searches for DM using other signatures

9

”MET+X” searches also include the following signatures:

- ”Intermediate” radiation (e.g. Higgs-strahlung) - MET = DM - X = decay products of the

particle that radiated the DM mediator

- Vector Boson Fusion - MET = DM - X = forward jets

Sensitive to a variety of models, e.g. Higgs decays to DM (see later), pure WIMP triplet, + others…

DM

DMq

W HW

q

q

q

ILC: H→inv., Z→qq

arXiv:1903.01629, p60

for illustration

Precision Higgs Physics at High-Energy Electron-Proton Colliders, LHeC Higgs Study Group, G.~Azuelos et al, in preparation.

LHeC: ZZ fusion eq → eqZZ → eqH






• Generally best reach to discovery of high-mass DM/mediators • Challenges: online data taking thresholds, simultaneous collisions (pile-up)

• Main experimental uncertainties: energy scales, simulation modeling, luminosity

Opportunities and challenges for DM @ hadron colliders

10

arXiv:1902.10229 and CMS-PAS-FTR-18-016 arXiv:1902.10229 and ATL-PHYS-PUB-2018-038

HL-LHC uncertainty on Higgs to invisible BR (VBF) depends on pile-up rejection method

V. Shiltsev’s talk

https://cds.cern.ch/record/2647700


https://indico.cern.ch/event/808335/contributions/3365194/attachments/1842104/3022374/Future_Shiltsev_EPPSU_2019_v8.pdf



11

Opportunities and challenges for DM @ lepton colliders

• Limited by CoM energy but clean environment → good reach in mMed/new energy scales

• Lower backgrounds → ILC/CLIC could run untriggered • Can probe lower masses, search for other

theory benchmarks at a later stage

• Specific strengths of lepton colliders: • clear tagging for Higgs recoiling against Z • beam polarization can enhance/help

identify signal

• Main experimental uncertainties: luminosity, electron identification (theory also similar magnitude)

M. Habermehl's PhD thesis

S. Campana’s talk G. Stewart’s talk

http://inspirehep.net/record/1717582/files/Moritz_Habermehl_PhD.pdf

https://indico.cern.ch/event/808335/contributions/3365192/attachments/1842346/3022240/FutureOfComputing-ESPP.pdf



Broad categories of searches for DM@colliders

�12

!12

Generic searches More specific searches•Good for simple models with sizable cross-sections •Fewer assumptions on specific model characteristics

•More sensitive to specific models •More reliant on model assumptions

DM

DMSM

SM

p, π, … → jets

W, Z → leptons, jets…

→ the way we think of benchmark models influences searches



Vector-like mediator

Scalar-like mediator and Two Higgs Doublet Models

Common benchmarks for collider WIMP searches

�13

!13

Simple models More complex/complete modelsSimple DM mediation Supersymmetry

Z/Higgs portals

gq gq

SM

SM

SM

SMDM

DM

gq g

SM SM

SM

DM

DMq

W HW

q

q

q

(Simplified model diagram)JHEP 03 (2018) 160

SM mediator Beyond-SM mediator

Also: DM models with long-lived particles

https://arxiv.org/abs/1801.03957



Vector-like mediator

Scalar-like mediator and Two Higgs Doublet Models

Common benchmarks for collider WIMP searches

�14

!14

Simple models More complex/complete modelsSimple DM mediation Supersymmetry

Z/Higgs portals

gq gq

SM

SM

SM

SMDM

DM

gq g

SM SM

SM

DM

DMq

W HW

q

q

q

(Simplified model diagram)JHEP 03 (2018) 160

SM mediator Beyond-SM mediatorM. McCullough’s talk

A. Weiler and M. D’Onofrio’s talks

Also: DM models with long-lived particles

G. Perez and G. Lanfranchi’s talks R. Poettgen and A. Vallier’s talks




Choice of benchmarks

15

from DM ATLAS feature

”Why comparing future colliders using such simple models?” ”Do we think DM is all made of a single WIMP model?” (not necessarily, see H. Murayama’s talk)

• Simplified models can encapsulate relevant experimental characteristics representing wider classes of theories

• Lesson from SM: most common particles discovered first

https://atlas.cern/updates/atlas-feature/dark-matter



Benchmarks of choice

16

• Large number of model possibilities for WIMPs, even limiting to the simplest models (see e.g. LHC Dark Matter Forum/WG documents)

•

• Higgs portal and scalar mediator are only examples • Why choosing them as benchmarks? • newly discovered Higgs • Higgs portal: simple interaction, only DM as new particle • Scalar cross-sections are small → can probe with future colliders

Ann.Rev.Nucl.Part.Sci. 68 (2018) 429-459

What cases of thermal relic WIMPs are still unprobed and can be covered by collider searches?

Problem: unable to cover all cases!

https://lpcc.web.cern.ch/content/dark-matter-wg-documents



Introduction Comparison to direct detectionBSM scalar mediatorHiggs portal

Higgs portal model

17

• How to detect invisibly decaying Higgs: • directly (MET searches)

• indirectly (deviation of SM coupling through fits, using K-framework) • including only σ x Branching Ratio (BR) measurements/ratios, no high-pT Higgs

keeping SM BR fixed, only allow invisible BR to float in the fit (subtracting SM) • Drawing from work by Higgs Physics Planning Group (PPG), arXiv:1905.03764

DM

DMq

W HW

q

q

q

• Different kinds of dark matter • Majorana fermion DM • Scalar DM • Vector DM: would need more advanced UV

completion, not covered here, see e.g. arXiv:1512.06853

arXiv:1903.03616

VBF signature Higgs-strahlung signature

Lambda for fermion EFT: assumed 1 TeV







Direct searches and coupling fits: summary

18

used for plotsused for plots

LHeC 5.5 (2-sigma, no syst.)HE-LHeC 3.4 (2-sigma, no syst.)FCC-eh 1.7 (2-sigma, no syst.)

arXiv:1905.03764

Precision Higgs Physics at High-Energy Electron-Proton Colliders, LHeC Higgs Study Group, G.~Azuelos et al, in preparation.




Higgs portal in DM context: relic density

19

• Very simple model, so careful with taking relic density at face value • If Higgs portal is to make up 100% of DM, can exclude using DD and colliders

arXiv:1903.03616




BSM scalar mediator

20

• How to detect new scalar mediators of DM: • invisible decays (MET searches)

• visible decays of scalar/pseudoscalar mediators • especially relevant in case of 2HDM+pseudoscalar

(HL-LHC benchmark)

• Dark matter type considered: • Dirac fermion DM

Also includes lepton couplings, requiring quark couplings for DD comparisons

Mono-jet search(or mono-photon)

In association with heavy flavor quarks(also: single top, Wt signatures)

4-top signatures

Yukawa couplings

Relic density: not entirely probed

arXiv:1606.00947


arXiv:1708.02245 & references






Results for scalar mediators

21

Hadron colliders Lepton colliders

arXiv:1509.02904

arXiv:1902.10229, p71 M. Habermehl's PhD thesis

J. J. Blaising, U. Schnoor, A. Wulzer, CLICdp



http://inspirehep.net/record/1717582/files/Moritz_Habermehl_PhD.pdf

Introduction


Comparison to direct detectionBSM scalar mediatorHiggs portal

Comparison to direct (and indirect) detection

22

How will Direct and Indirect DM Detection experiments inform/guide accelerator searches and vice-versa?

• Why we need complementarity: • DD/ID can discover DM with cosmological origin • Colliders can probe the dark interaction (even when DM is inaccessible)

Particle CollidersDirect DetectionIndirect Detection

Complementary experiments tackling DM problem

?

C. Doglioni - 30/10/2018 - Puzzle of DM, DESY

Complementarity of DM experiments

!23

Comparisons are possible only in the context of a model Essential to fully specify model/parameters and be aware of limitations

Wikipedia/NASA

LHC Dark Matter Working Grouphttps://arxiv.org/abs/1603.04156

For more thoughts on upper bounds to collider sensitivity: arXiv:1810.07705 and DMWG meeting June 2017

How we compare results of different experiments in a more model independent way possible?

Complementarity of colliders with direct (indirect) detection performed within the chosen benchmark models & parameters


https://indico.cern.ch/event/563066/contributions/2306614/attachments/1340042/2017991/DMWG-09-20-16.pdf

Introduction Higgs to invisible


Comparison to direct detectionBSM scalar mediator

Higgs portal, plot for direct searches

24

DM

DMq

W HW

q

q

q

• Limits on BR can be translated to limits in the DM-nucleon plane

arXiv:1708.02245

1 10 102 310mχ [GeV]

−5010

−4910

−4810

10−47

−4610

−4510

10−44

σ(χ-nucleon)[cm

2 ]SI

Direct searches, Majorana DMHiggs Portal model

Collider limits at 95% CL, direct detection limits at 90% CL

XENON1

T

PRL 121 (2018) 111302XENON1T

PandaX

PRL 117 (2016) 121303PandaX

LUX PRL 118 (2017) 021303LUX

DarkSide-Argo (proj.)

DarkSide-Argo EPPSU submission


DARWIN-200 (proj.)

JCAP 11 (2016) 017

DARWIN-200 (proj.)

Higgs PPG, arXiv:1905.03764

HL-LHC, BR<2.6


HL-LHC+LHeC, BR<2.3


CEPC, FCC-ee240, ILC

250: BR<0.3%


FCC-ee/eh/hh, BR<0.025

Preliminary, Granada May 2019

1 10 102 310mχ [GeV]

−4810

10−47

−4610

−4510

10−44

−4310

10−42

σ(χ-nucleon)[cm

2 ]SI

Direct searches, Scalar DM

XENON1

T

PRL 121 (2018) 111302XENON1T

PandaX

PRL 117 (2016) 121303PandaX

DarkSide-50PRL 121 (2018) 081307DarkSide-50

LUX

PRL 118 (2017) 021303LUX




DARWIN-200 (proj.)

JCAP 11 (2016) 017

DARWIN-200 (proj.)

Higgs PPG, arXiv:1905.03764HL-LHC: BR<2.6%

Higgs PPG, arXiv:1905.03764HL-LHC+LHeC: BR<2.3%


CEPC, FCC-ee240, ILC

250: BR<0.3%

Higgs PPG, arXiv:1905.03764FCC-ee/eh/hh: BR<0.025%


Higgs Portal model


Caveat: EFT validity in Higgs-DM

interaction not guaranteed beyond

HL-LHC





Higgs portal, plot for direct searches

25

DM

DMq

W HW

q

q

q

• Limits on BR can be translated to limits in the DM-nucleon plane



HL-LHC

arXiv:1708.02245

1 10 102mχ [GeV]

−5010

−4910

−4810

10−47

−4610

σ(χ-nucleon)[cm

2 ]SI

Fits, Majorana DMHiggs Portal model


PRL 121 (2018) 111302XENON1T

PRL 117 (2016) 121303PandaX

PRL 118 (2017) 021303LUX



JCAP 11 (2016) 017

DARWIN-200 (proj.)


Higgs PPG, arXiv:1905.03764HL-LHC+HE-LHC: BR<1.5%



CLIC380: BR<0.60%


CLIC1500: BR<0.41%


CLIC3000: BR<0.3%

Higgs PPG, arXiv:1905.03764CEPC: BR<0.26%


ILC250: BR<0.25%


ILC500: BR<0.22%


FCCee,240: BR<0.22%


FCCee: BR<0.19%


1 10 102mχ [GeV]

−4810

10−47

−4610

−4510

10−44

σ(χ-nucleon)[cm

2 ]SI

Fits, Scalar DMHiggs Portal model


PRL 121 (2018) 111302XENON1T

PRL 117 (2016) 121303PandaX

PRL 118 (2017) 021303LUX



JCAP 11 (2016) 017

DARWIN-200 (proj.)


Higgs PPG, arXiv:1905.03764HL-LHC+HE-LHC: BR<1.5%



CLIC380: BR<0.60%


CLIC1500: BR<0.41%


CLIC3000: BR<0.3%

Higgs PPG, arXiv:1905.03764CEPC: BR<0.26%


ILC250: BR<0.25%


ILC500: BR<0.22%


FCCee,240: BR<0.22%


FCCee: BR<0.19%





Collider reach and relic density

26

What cases of thermal relic WIMPs are still unprobed and can be covered by collider searches?

• Very simple model, so careful with taking relic density at face value • If Higgs portal is to make up 100% of DM, can exclude using DD and colliders

arXiv:1903.03616

Approximate Future colliders reach



HL-LHC

Approximate Future colliders reach





1 10 102 310mχ [GeV]

−5110

−5010

−4910

−4810

10−47

−4610

−4510

10−44

−4310

10−42

10−41

−4010

−3910

−3810σ

(χ-nucleon)[cm

2 ]SI

= 1= 1, gSM,f

gDM

Scalar model, Dirac DM


CRESST III

arXiv:1904.00498CRESST III

XENON1T

PRL 121 (2018) 111302XENON1T

PandaX

PRL 117 (2016) 121303PandaX

DarkSide-50

PRL 121 (2018) 081307DarkSide-50

LUX

PRL 118 (2017) 021303LUX

Darkside-Argo(proj.)


Argo-3000 (proj.)

DARWIN-200 (proj.)

JCAP 11 (2016) 017

DARWIN-200 (proj.)-1

HL-LHC, 14 TeV,3 ab

HL/HE-LHC Report: arXiv:1902.10229

HL-LHC, 14 TeV, 3 ab-1

-1

HE-LHC, 27 TeV,15 ab HL/HE-LHC Report: arXiv:1902.10229

HE-LHC, 27 TeV, 15 ab-1

-1

FCC-hh, 100 TeV,1 ab

PRD 93 (2016) 054030

FCC-hh, 100 TeV, 1 ab-1

-1


Rescaling of PRD 93 (2016) 054030



Scalar mediator, hadron colliders and direct detection

27

• Limits on scalar mediator mass/scale can be translated to limits in the DM-nucleon plane

arXiv:1603.04156

ttbar+MET

V/jet+MET





1 10 102 310mχ [GeV]

−5110

−5010

−4910

−4810

10−47

−4610

−4510

10−44

−4310

10−42

10−41

−4010

−3910

−3810σ

(χ-nucleon)[cm

2 ]SI

= 1= 1, gSM,f

gDM



CRESST III


XENON1T

PRL 121 (2018) 111302XENON1T

PandaX

PRL 117 (2016) 121303PandaX

DarkSide-50

PRL 121 (2018) 081307DarkSide-50

LUX

PRL 118 (2017) 021303LUX



Argo-3000 (proj.)

DARWIN-200 (proj.)

JCAP 11 (2016) 017


HL-LHC, 14 TeV,3 ab



-1



-1


PRD 93 (2016) 054030


-1






28

• Limits on scalar mediator mass/scale can be translated to limits in the DM-nucleon plane

arXiv:1603.04156

ttbar+MET

V/jet+MET Keep in mind: these plots are only valid for the couplings specified,

even in the limited space of a benchmark model!





1 10 102 310mχ [GeV]

−5110

−5010

−4910

−4810

10−47

−4610

−4510

10−44

−4310

10−42

10−41

−4010

−3910

−3810σ

(χ-nucleon)[cm

2 ]SI

= 1= 1, gSM,f

gDM



CRESST III


XENON1T

PRL 121 (2018) 111302XENON1T

PandaX

PRL 117 (2016) 121303PandaX

DarkSide-50

PRL 121 (2018) 081307DarkSide-50

LUX

PRL 118 (2017) 021303LUX



Argo-3000 (proj.)

DARWIN-200 (proj.)

JCAP 11 (2016) 017


HL-LHC, 14 TeV,3 ab



-1



-1


PRD 93 (2016) 054030


-1






29

ttbar+MET

V/jet+MET

All benchmarks: complementary reach for future colliders and DD




Scalar mediator, comparison of lepton colliders

30

●No summary plot for scalar mediator and lepton colliders●In order to compare to DD, one would need: 1) quark couplings (DM-nucleon interaction) 2) model-dependent statement for quark/lepton coupling ratio → only compare mediator/EFT reach at fixed mDM with the same coupling assumptions

Example of DD reach for leptophilic DM model

arXiv:1507.07747

Scalar mediator, fermion couplings = 1, gDM = 1, mDM=1 GeV

● ILC (@ 90% CL): [M. Habermehl’s thesis] - sqrt(s)=250 GeV, 2/ab : 1250 GeV - sqrt(s)=500 GeV, 4/ab: 2710 GeV (@95% CL, 10/ab): about 150 GeV lower● CLIC (@95% CL, 5/ab, no beam polarization): [private communication with U. Schnoor, J. J. Blasing, A. Wulzer, CLIC Collab.]

- sqrt(s)=3000 GeV: 4600 GeV • CEPC results w/o systematics also available: [arXiv:1903.12114]


http://inspirehep.net/record/1717582?ln=en




Conclusions & outlook

31

Huge progress planned on DD and ID front (see earlier talks in this session)Future colliders can follow: essential complementarity between

This talk covered simple models used for comparison and contextualization: - SM-DM interactions mediated by Higgs boson - SM-DM interactions mediated by new scalar particle

Strengths in WIMP searches both in future lepton and hadron options: - combined FCC program shows best sensitivity to benchmarks

- still, needs complementary experiments (DM != WIMP only) - lepton colliders alone can probe large parts of phase space

thanks to precision environment

Next 10 years: hope for concerted effort between DD/ID/colliders/other experiments

to discover and understand a possible particle nature of DM

andcosmological origin DD/ID/astrophysics

nature of the DM-SM interaction colliders(/beam dumps)

32

Thanks for your attention!

Introduction



Contributions considered

33

Full programs include earlier versions / CoM energieshttps://arxiv.org/abs/1905.03764

29 CEPC Input to the ESPP 2018 - Physics and Detector 77 The International Linear Collider. A Global Project 100 Precision calculations for high-energy collider processes 101 Theory Requirements and Possibilities for the FCC-ee and other Future High Energy and Precision Frontier Lepton Colliders 132. Future Circular Collider - The Lepton Collider (FCC-ee) 133. Future Circular Collider - The Hadron Collider (FCC-hh) 135 Future Circular Collider - The Integrated Programme (FCC-int) 136 Future Circular Collider - The High-Energy LHC (HE-LHC) 145 The Compact Linear e$^+$e$^-$ Collider (CLIC): Physics Potential 152 The physics potential of HL-LHC 159 Exploring the Energy Frontier with Deep Inelastic Scattering at the LHC 160 The physics potential of HE-LHC


Introduction



Input scenarios for colliders, from Higgs PPG

34

Full programs include earlier versions / CoM energieshttps://arxiv.org/abs/1905.03764


Introduction



Timeline of colliders, from Higgs PPG

35



Introduction



Luminosity-scaled FCC-hh

36

Phil Harris, luminosity rescaling

mediator limit @ 100/fb: 3200 GeV mediator limit @ 30/fb: 2500 GeV

Introduction



Systematics for Higgs to invisible (ILC)

37

Introduction



Example: systematics for Higgs to invisible (ILC)

38

Akimasa Ishikawa, slides from ILC meeting 2014

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=2ahUKEwjb-IrKiJjiAhVE-YUKHZ9HCHAQFjACegQIABAC&url=https://agenda.linearcollider.org/event/6506/session/1/contribution/58/material/slides/0.pptx&usg=AOvVaw1r_FQ8oF-vyXdvAEHTgKij



Uncertainties on DD for comparison to colliders

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• DD is subject to astrophysical uncertainties, how much do they matter when comparing to collider searches? Note: collider searches have uncertainties too!

Isabelle John, Lund University Master’s thesis in preparation



Uncertainties on DD for comparison to colliders

40

• DD is subject to astrophysical uncertainties, how much does it matter when comparing to collider searches? Note: collider searches have uncertainties too!

arXiv:1903.03616arXiv:1903.03616





Higgs portal and relic density, beyond mH/2

41

arXiv:1903.03616


Introduction



Alternative relic density scenario

42

arXiv:1903.03616




Relic density and FCC-hh, simplified models

43





Impact of pile-up on HL-LHC uncertainties

44



Dark Matter at colliders · 2019. 6. 4. · Benchmarks of choice 16 • Large number of model...

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