[PPT] - LHC Signatures of a Minimal Supersymmetric Hidden Valley PowerPoint Presentation

SLIDE 1

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

LHC Signatures of a Minimal Supersymmetric Hidden Valley

arXiv:1112.2705 Yuk Fung Chan1 Matt Low2 David Morrissey3 Andrew Spray3

1Program in Applied and Computational Mathematics, Princeton University 2Enrico Fermi Institute, University of Chicago 3Theory Group, TRIUMF

TRIUMF Workshop on LHC Results, 16th December 2011

SLIDE 2

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Introduction Background The Model To and From the Hidden Valley MSSM Decays In Hidden Decays Out Collider Objects Hidden Sector Parameter Scan Number of HV Jets Presence of Displaced Vertices Five Sample Points Overview Collider Signals

SLIDE 3

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Helpful Notes on Hidden Valleys

Essential Features of a Hidden Valley:

New light sector O(GeV)
New heavy sector O(TeV)
Feeble SM-light coupling
Efficient heavy-SM and -light

couplings At LHC, SM → Heavy → Light → SM New, interesting signals BUT! broad, ill-defined model space

SLIDE 4

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Simple Review of Supersymmetry

Well-motivated extension of SM

Symmetry relating fermions ↔ bosons
Exception to Coleman-Mandula Theorem
O(TeV)-scale partners of SM particles

(With opposite spin-statistics)

Solves hierarchy problem

R-Parity:

Discrete symmetry:

SM Even, New particles Odd

Added for proton stability, DM
Characterises SUSY events

SLIDE 5

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Supersymmetric Hidden Valleys

A Tasty Blend

What do hidden valleys gain from SUSY?

Get heavy sector for free
“Natural” hierarchy of scales
Concrete implementation

What does supersymmetry gain?

New phenomenology
Light sectors in GUTs
Light dark matter?

SLIDE 6

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Supersymmetric Hidden Valleys

A Tasty Blend

What do hidden valleys gain from SUSY?

Get heavy sector for free
“Natural” hierarchy of scales
Concrete implementation

What does supersymmetry gain?

New phenomenology
Light sectors in GUTs
Light dark matter?

SLIDE 7

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Supersymmetric Hidden Valleys

A Tasty Blend

What do hidden valleys gain from SUSY?

Get heavy sector for free
“Natural” hierarchy of scales
Concrete implementation

What does supersymmetry gain?

New phenomenology
Light sectors in GUTs
Light dark matter?

SLIDE 8

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Philosophy Our point is not that this model is True Our point is that it is Minimal yet Diverse That is, a Benchmark

SLIDE 9

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Overview and New Particle Content

Starting point: MSSM
Hidden sector SM-neutral
Supersymmetric sector-coupling
Options:
Chiral superfield, Higgs portal
Vector superfield, kinetic mixing

New Fields:

1. Vector superfield
2. Two Higgs superfields
1. Massive vector Xµ
2. Three real scalars hx

1,2, Ax

3. Three Majorana fermions

χx

1,2,3

SLIDE 10

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Overview and New Particle Content

Starting point: MSSM
Hidden sector SM-neutral
Supersymmetric sector-coupling
Options:
Chiral superfield, Higgs portal
Vector superfield, kinetic mixing

New Fields:

1. Vector superfield
2. Two Higgs superfields
1. Massive vector Xµ
2. Three real scalars hx

1,2, Ax

3. Three Majorana fermions

χx

1,2,3

SLIDE 11

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Overview and New Particle Content

Starting point: MSSM
Hidden sector SM-neutral
Supersymmetric sector-coupling
Options:
Chiral superfield, Higgs portal
Vector superfield, kinetic mixing

New Fields:

1. Vector superfield
2. Two Higgs superfields
1. Massive vector Xµ
2. Three real scalars hx

1,2, Ax

3. Three Majorana fermions

χx

1,2,3

SLIDE 12

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Overview and New Particle Content

Starting point: MSSM
Hidden sector SM-neutral
Supersymmetric sector-coupling
Options:
Chiral superfield, Higgs portal
Vector superfield, kinetic mixing

New Fields:

1. Vector superfield
2. Two Higgs superfields
1. Massive vector Xµ
2. Three real scalars hx

1,2, Ax

3. Three Majorana fermions

χx

1,2,3

SLIDE 13

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Kinetic Mixing

L ⊃

d2θ ǫ

2 BαXα ⊃ ǫ

− 1

2BµνXµν + i 2 ˜ B†¯ σ · ∂˜ X + i 2 ˜ X†¯ σ · ∂˜ B + DYDX

Xµ → SM;
(Rare) Z → HV
˜

B → HV

SUSY to HV
hx

1 → SM

(Rare) Higgs → HV

Possible source:

✁

˜ X ˜ B Expect ǫ ∼ 10−2 – 10−4

102 101 1 109 108 107 106 105 104 103 102 102 101 1 109 108 107 106 105 104 103 102 mA' GeV Ε E137 E141 E774 aΜ ae 3S SN

[0906.0580, Bjorken, Essig, Schuster, Toro]

SLIDE 14

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Kinetic Mixing

L ⊃

d2θ ǫ

2 BαXα ⊃ ǫ

− 1

2BµνXµν + i 2 ˜ B†¯ σ · ∂˜ X + i 2 ˜ X†¯ σ · ∂˜ B + DYDX

Xµ → SM;
(Rare) Z → HV
˜

B → HV

SUSY to HV
hx

1 → SM

(Rare) Higgs → HV

Possible source:

✁

˜ X ˜ B Expect ǫ ∼ 10−2 – 10−4

102 101 1 109 108 107 106 105 104 103 102 102 101 1 109 108 107 106 105 104 103 102 mA' GeV Ε E137 E141 E774 aΜ ae 3S SN

[0906.0580, Bjorken, Essig, Schuster, Toro]

SLIDE 15

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Kinetic Mixing

L ⊃

d2θ ǫ

2 BαXα ⊃ ǫ

− 1

2BµνXµν + i 2 ˜ B†¯ σ · ∂˜ X + i 2 ˜ X†¯ σ · ∂˜ B + DYDX

Xµ → SM;
(Rare) Z → HV
˜

B → HV

SUSY to HV
hx

1 → SM

(Rare) Higgs → HV

Possible source:

✁

˜ X ˜ B Expect ǫ ∼ 10−2 – 10−4

102 101 1 109 108 107 106 105 104 103 102 102 101 1 109 108 107 106 105 104 103 102 mA' GeV Ε E137 E141 E774 aΜ ae 3S SN

[0906.0580, Bjorken, Essig, Schuster, Toro]

SLIDE 16

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Kinetic Mixing

L ⊃

d2θ ǫ

2 BαXα ⊃ ǫ

− 1

2BµνXµν + i 2 ˜ B†¯ σ · ∂˜ X + i 2 ˜ X†¯ σ · ∂˜ B + DYDX

Xµ → SM;
(Rare) Z → HV
˜

B → HV

SUSY to HV
hx

1 → SM

(Rare) Higgs → HV

Possible source:

✁

˜ X ˜ B Expect ǫ ∼ 10−2 – 10−4

102 101 1 109 108 107 106 105 104 103 102 102 101 1 109 108 107 106 105 104 103 102 mA' GeV Ε E137 E141 E774 aΜ ae 3S SN

[0906.0580, Bjorken, Essig, Schuster, Toro]

SLIDE 17

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

The Hidden Sector Lagrangian

New Supersymmetric terms: W = WMSSM − µ′ H H′ (plus gauge, Kähler terms → gx, ǫ) Agnostic ✘✘✘

✘

SUSY; hidden soft terms generic, real & O(GeV) −Lhid,soft = mH2 |H|2 + mH′2 H′ 2 +

−b′ H H′ + 1

2Mx˜ X˜ X + h.c.

7 new parameters mx, mAx, tan ζ

Mixing matrices: Fermion P, Scalar R (See paper for details)

SLIDE 18

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

The Hidden Sector Lagrangian

New Supersymmetric terms: W = WMSSM − µ′ H H′ (plus gauge, Kähler terms → gx, ǫ) Agnostic ✘✘✘

✘

SUSY; hidden soft terms generic, real & O(GeV) −Lhid,soft = mH2 |H|2 + mH′2 H′ 2 +

−b′ H H′ + 1

2Mx˜ X˜ X + h.c.

7 new parameters mx, mAx, tan ζ

Mixing matrices: Fermion P, Scalar R (See paper for details)

SLIDE 19

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

The Hidden Sector Lagrangian

New Supersymmetric terms: W = WMSSM − µ′ H H′ (plus gauge, Kähler terms → gx, ǫ) Agnostic ✘✘✘

✘

SUSY; hidden soft terms generic, real & O(GeV) −Lhid,soft = mH2 |H|2 + mH′2 H′ 2 +

−b′ H H′ + 1

2Mx˜ X˜ X + h.c.

7 new parameters mx, mAx, tan ζ

Mixing matrices: Fermion P, Scalar R (See paper for details)

SLIDE 20

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

The Nature of the LSMP

LSMP: The Lightest SM Partner : stable without HV (R-Parity) LSMP decay is dominant HV production. LSMP can be:

Sfermion
Gluino
Suppressed decays
Possible R hadrons
Neutralino

✁

˜ f ˜ f f χx f χx H

SLIDE 21

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

The Nature of the LSMP

LSMP: The Lightest SM Partner : stable without HV (R-Parity) LSMP decay is dominant HV production. LSMP can be:

Sfermion
Gluino
Suppressed decays
Possible R hadrons
Neutralino

✁

˜ f ˜ f f χx f χx H

SLIDE 22

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

The Nature of the LSMP

LSMP: The Lightest SM Partner : stable without HV (R-Parity) LSMP decay is dominant HV production. LSMP can be:

Sfermion
Gluino
Suppressed decays
Possible R hadrons
Neutralino

✁

˜ f ˜ f f χx f χx H

SLIDE 23

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

The Nature of the LSMP

LSMP: The Lightest SM Partner : stable without HV (R-Parity) LSMP decay is dominant HV production. LSMP can be:

Sfermion
Gluino
Suppressed decays
Possible R hadrons
Neutralino

✁

˜ g ˜ g q ¯ q χx χx H ¯ q q

SLIDE 24

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

The Nature of the LSMP

LSMP: The Lightest SM Partner : stable without HV (R-Parity) LSMP decay is dominant HV production. LSMP can be:

Sfermion
Gluino
Suppressed decays
Possible R hadrons
Neutralino

✁

˜ B χx H

SLIDE 25

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Decays of a Neutralino LSMP

✁

˜ B χx H, H′, X

LSMP decays via kinetic-mixing:

L ⊃ √ 2gxǫ

H∗ ˜

H˜ B − H′∗ ˜ H′˜ B

Decay to fermion + boson
All seven hidden states accessible

(Goldstone boson → vector) Branching Ratios: ˜ B →            Ax + χx 0.25 hx

1 + χx

0.25 hx

2 + χx

0.25 Xµ + χx 0.25 ˜ B →      χx

1 + Sx

|P11|2 + |P12|2 χx

2 + Sx

|P21|2 + |P22|2 χx

3 + Sx

|P31|2 + |P32|2 Decay Width Γ ∼ 10−18 s.

SLIDE 26

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

The Hidden Vector

✁

Xµ χx χx Ax hx

1

¯ f f

Xµ-SM coupling from kinetic mixing

⇒ Strength ǫQecw

So vector can decay to SM
Vector produced boosted

⇒ Decay products boosted

Two boosted, collimated quarks/leptons
BUT! Xµ can also decay to HV
Hidden decays dominate if allowed

SLIDE 27

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

The Lightest Hidden Scalar

hx

1 lightest hidden boson

Often has no hidden decays
Can decay to SM:
1. Xµ loop
2. Mass mixing with Higgs
Mass mixing dominates . . .
. . . But still collider-stable

✁

hx

1

hx

1

f ¯ f f ¯ f

0.01 0.1 1 10 mh1

x (GeV)

10

2

10 10

2

10

4

10

6

10

8

10

12

10

14

10

16

cτ (cm)

Higgs mixing alone loop alone total cτ = 10m

SLIDE 28

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Other Hidden Sector Particles

χx

1 is stable by R-parity

Other particles usually decay within hidden sector
Exceptions DO exist:
Ax → hx

1X∗ µ → hx 1f¯

f

hx

2 → AxX∗ µ → Axf¯

f

χx

2 → χx 1X∗ µ → χx 1f¯

f

Note: the second implies the first

SLIDE 29

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Lepton Jets

R R ∆ ∆ . . . ... j j χ χ

1 n a

S χ

i 1 1 x x

LSMP decay products boosted
Collimated in angle

∆R ∼ 1/γ ∼ mhid/mLSMP ∼ 10−3

If leptons produced:

Lepton jet

If quarks produced:

Jet with substructure

Both case tricky
Both cases, Two hard subobjects
Call either an HV Jet

SLIDE 30

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Displaced Vertices

For our values of ǫ and masses

Xµ always prompt
hx

1 always collider stable

Displaced vertices only from Three Body decays Can have a range of metastable lifetimes From cτ ≪ mm – cτ ≫ km Obviously, things that leave tracks easier to see

SLIDE 31

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Putting it All Together

R R ∆ ∆ . . . ... j j χ χ

1 n a

S χ

i 1 1 x x

{MSSM cascade} ⊕            0 HV jets 1 HV jet prompt/ 2 HV jets ⊗ displaced 3 HV jets track 4 HV jets           

SLIDE 32

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Definition of the Scan

Explore parameter space:

Scan with log priors
20 000 points
Decay tables:
Calculate with BRIDGE
Hidden states & LSMP
Boosts:

Ehid = mLSMP/2 = 150 GeV

Particles → decay tables
Find all LSMP final states

& branching ratios Parameter Range mx (0.1, 10) GeV mAx (0.1, 10) GeV Mx (0.1, 10) GeV µ′ ± (0.1, 10) GeV tan ζ (0.1, 10) Fix:

gx = 0.3
ǫ = 10−3
LSMP:

300 GeV pure Bino

SLIDE 33

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Number of “HV Jets”

PB = ˜

B → Sx → SM

PF = ˜

B → χx → SM

PB ∈ (0, 0.8)
PF ∈ (0, 1)
Obvious structure here.

SLIDE 34

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Structure I: Hidden Sector Bosons

Structure in PB:

Favours 0, 0.25, 0.5, 0.75
Recall: Br(˜

B → Sx) = 0.25

0: Xµ → hidden
0.25: Xµ → SM
0.5: Xµ, Ax → SM
0.75: Xµ, Ax, h2

x → SM

Note: hx

1 collider stable

Elsewhere: Sx → χxχx

SLIDE 35

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Structure II: Hidden Sector Fermions

Structure in PF:

Agglomerations at 0, 0.5
Light Higgsinos:
χx

2 → hx 1χx 1 invisible

χx

2 off-shell visible

Heavy Higgsinos

Decays to hx

1, Xµ

SLIDE 36

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Structure II: Hidden Sector Fermions

0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 pB pF 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 pB pF

SLIDE 37

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Structure III: Hidden Sector Fermions & Bosons

Last structure: PB ≈ PF

χx

j → Sxχx i

Fermions decay to all

scalars

OR to most scalars

SLIDE 38

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Correlations in Hidden Cascades

Average no. HV Jets PB + PF
But decays correlated
Define C = PBPF − ˜

P2

C, PB and PF define Bino decay

SLIDE 39

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Long-Lived Bosons

0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 pB Displaced pB Prompt

All Displaced: Xµ → hidden
All Prompt: All two-body
Mixed: Xµ →SM, Ax off-shell

SLIDE 40

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Long-Lived Fermions

0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 pF Displaced pF Prompt

All Displaced:
χx

2 off-shell; or

Xµ → hidden
All Prompt: All two-body
The rest: off-shell scalars

SLIDE 41

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Five Sample Points

Now have overview of parameter space Select Five points for further study Selected based on phenomenology, not spectrum:

1. Invisible: PB ≈ PF ≈ 0
2. Vector only: ˜

B → Xµ →SM, ˜ B → χx, Sx invisible

3. Pure displacement: Xµ → hidden, but three-body Ax
4. Lots of stuff; PB ≈ PF ≈ 0.5, complex decay chains
5. Multiple Displaced; Xµ →SM, Ax and χx

2 three-body

See paper for parameters, spectra

SLIDE 42

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Generating Events

We don’t care about MSSM phenomenology ⇒ Take simplified spectrum:

300 GeV Bino
800 GeV gluino
Everything else 2.5 GeV
Not ruled out Yet!

Model ⇒ FeynRules, MadGraph ⇒ 50 000 events pp → ˜ g˜ g 7 TeV

σ ∼ 200 fb
Everything else irrelevant
4 jets from gluinos + HV cascades

SLIDE 43

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Defining “Collider” Objects

Experimentalists look away now!

A “HV Jet”:

1. (At least) Two partons, pT > 20 GeV and ∆R < 0.1
2. Within ∆R < 0.4, extra pT < 3 GeV
3. No distinction between leptons vs quarks, gluons
4. No showering, detector resolution effects

A “Jet”:

1. Not an HV Jet
2. pT > 20 GeV
3. Jet Size R = 0.4

SLIDE 44

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Tag Efficiencies & Number of (HV) Jets

Point HV Jet Tag Efficiency HV2 88% HV3 50% HV4 62% HV5 55% Note: most failed HV jets tagged as jets

SLIDE 45

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

HV Jet pT

100 200 300 400 500 600 0.0 0.2 0.4 0.6 0.8 pT of Hardest HV Jet GeV dΣ dpT fb GeV1 100 200 300 400 500 600 0.000 0.002 0.004 0.006 0.008 pT of Hardest HV Jet GeV 1 Σ dΣ dpT GeV1

HV2: hardest HV jets

(all from Xµ → f¯ f)

HV3 notably soft

(all from Ax → hx

1f¯

f)

SLIDE 46

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Missing Transverse Energy

More visible ⇒ less ET

/

Still lots of ET

/ in all cases

SLIDE 47

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Missing Transverse Energy

More visible ⇒ less ET

/

Still lots of ET

/ in all cases

SLIDE 48

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Displaced Vertices

0.1 1 10 100 1000 1 2 5 10 20 50 100 200 Displacement, l mm dΣ dl fb mm1

Again: no detector effects
HV5 “double-bump”:

hint to HV structure?

SLIDE 49

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

Monojets

Benchmark Monojet Branching Ratio HV1 0% HV2 27% HV3 10% HV4 18% HV5 12% [Used ATLAS LowPT Tags] pp → 2 LSMP → monojets

Irrelevant for Bino LSMP
Interesting for Wino,

Higgsino?

Possible for all but HV1

SLIDE 50

Introduction To and From the Hidden Valley Hidden Sector Parameter Scan Five Sample Points Conclusions

MSSM + Higgsed U(1) is Minimal SUSY HV
Model has Diverse phenomenology:

R-Hadrons, displaced vertices, lepton jets, monojets . . .

It is therefore a possible Benchmark
We have Scanned HV Parameter Space