Beyond the Higgs Boson Particle Physics at the Verge of More - - PowerPoint PPT Presentation

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Beyond the Higgs Boson Particle Physics at the Verge of More - - PowerPoint PPT Presentation

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Cluster of Excellence Precision Physics, Fundamental Interactions and Structure of Matter Beyond the Higgs Boson Particle Physics at the Verge of More Discoveries? Matthias Neubert Mainz Institute for Theoretical Physics (MITP) and PRISMA

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SLIDE 1

Beyond the Higgs Boson

Particle Physics at the Verge of More Discoveries?

Matthias Neubert — Mainz Institute for Theoretical Physics (MITP) and PRISMA Cluster of Excellence Johannes Gutenberg University, Mainz

25 January 2016 — 54th International Winter Meeting on Nuclear Physics, Bormio

ERC Advanced Grant (EFT4LHC) An Effective Field Theory Assault on the Zeptometer Scale: Exploring the Origins of Flavor and Electroweak Symmetry Breaking Cluster of Excellence Precision Physics, Fundamental Interactions and Structure of Matter

Based on collaborations with Martin Bauer (arXiv:1511:01900, 1512:06828)

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SLIDE 2

2

Overview

Matthias Neubert: Beyond the Higgs Boson

1 2 3 4

Discovery of the Higgs Boson Hints for New Physics One Leptoquark to Rule Them All One Leptoquark to Rule Them All

5

Outlook

A new kind of particle Dark matter, flavor anomalies and diboson resonances Part I: Flavor anomalies Part II: Diphoton resonance S(750)

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SLIDE 3

3

Discovery of the Higgs boson: A new kind of particle

4 July 2012: A milestone in the history of physics

Matthias Neubert: Beyond the Higgs Boson

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SLIDE 4

4

Discovery of the Higgs boson: A new kind of particle

The Standard Model of particle physics is complete! The Higgs mechanism predicts the existence of a medium penetrating all of spacetime (like an ether) In any relativistic quantum theory a field can be excited to vibrate — the vibrations of the Higgs medium consist of Higgs bosons The Higgs discovery provides an experimental proof for the existence of the Higgs medium

Matthias Neubert: Beyond the Higgs Boson

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SLIDE 5

Properties of the Higgs bosons: Higgs couplings are Standard Model-like within present experimental accuracy!

5

) µ Signal strength (

1 − 1 2 3

ATLAS Preliminary

  • 1

= 7 TeV, 4.5-4.7 fb s

  • 1

= 8 TeV, 20.3 fb s

= 125.36 GeV

H

m

0.26

  • 0.28

+

= 1.17 µ γ γ → H

0.08
  • 0.12
+ 0.11
  • 0.16
+ 0.23
  • 0.23
+

0.34

  • 0.40

+

= 1.46 µ ZZ* → H

0.11
  • 0.18
+ 0.13
  • 0.19
+ 0.31
  • 0.35
+

0.21

  • 0.24

+

= 1.18 µ WW* → H

0.09
  • 0.13
+ 0.14
  • 0.17
+ 0.16
  • 0.16
+

0.37

  • 0.39

+

= 0.63 µ b b → H

0.07
  • 0.09
+ 0.23
  • 0.24
+ 0.30
  • 0.31
+

0.37

  • 0.42

+

= 1.44 µ τ τ → H

0.10
  • 0.16
+ 0.23
  • 0.29
+ 0.29
  • 0.30
+

3.7

  • 3.7

+

= -0.7 µ µ µ → H

0.4
  • 0.4
+ 0.7
  • 0.5
+ 3.6
  • 3.6
+

4.5

  • 4.6

+

= 2.7 µ γ Z → H

0.3
  • 1.1
+ 1.3
  • 1.7
+ 4.2
  • 4.3
+

0.14

  • 0.15

+

= 1.18 µ

Combined

0.07
  • 0.08
+ 0.10
  • 0.11
+ 0.10
  • 0.10
+

Total uncertainty µ

  • n

σ 1 ±

(stat.) σ

)

theory sys inc.

(

σ (theory) σ

SM

σ / σ Best fit

0.5 1 1.5 2

0.44 ± = 0.84 µ

bb tagged → H

0.28 ± = 0.91 µ

tagged τ τ → H

0.21 ± = 0.83 µ

WW tagged → H

0.29 ± = 1.00 µ

ZZ tagged → H

0.24 ± = 1.12 µ

tagged γ γ → H

0.14 ± = 1.00 µ

Combined

CMS

(7 TeV)

  • 1

(8 TeV) + 5.1 fb

  • 1

19.7 fb

= 125 GeV

H

m

= 0.96

SM

p

µ = σ(pp → H) · BR(H → X) σ(pp → H)SM · BR(H → X)SM

Is it the Higgs boson of the Standard Model?

Matthias Neubert: Beyond the Higgs Boson

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SLIDE 6

6

“This could be the discovery of the century. Depending, of course, on how far down it goes.”

Is it the Higgs boson of the Standard Model?

H

Matthias Neubert: Beyond the Higgs Boson

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SLIDE 7

7

Is Nature natural?

Matthias Neubert: Beyond the Higgs Boson

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SLIDE 8

8

ie& en& &

Is Nature natural?

Hierarchie problem suggested that a “natural” theory

  • f electroweak symmetry breaking should contain

new colored particle near the weak scale Existence of dark matter suggested that there should be new weakly interacting particles near the weak scale (WIMP miracle)

Where are they?

Matthias Neubert: Beyond the Higgs Boson

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SLIDE 9

9

Is Nature natural?

Where are they?

Matthias Neubert: Beyond the Higgs Boson

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SLIDE 10

Hints for New Physics

Dark matter, flavor anomalies and diboson resonances

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SLIDE 11

11

On the verge of another discovery?

While we have not observed any of the expected faces of new physics, there exist several tantalizing hints of effects which cannot be explained by the Standard Model

  • Dark matter
  • Neutrino masses and mixings
  • Anomalous magnetic moment of the muon
  • Various anomalies in the flavor sector
  • Hints for new heavy resonances from the LHC

+ ???

Matthias Neubert: Beyond the Higgs Boson

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SLIDE 12

12

Anomalies in the flavor sector

∼ 3.5 (g − 2)µ anomaly ∼ 3.5 non-standard like-sign dimuon charge asymmetry ∼ 3.5 enhanced B → D(⇤)⌧⌫ rates ∼ 3.5 suppressed branching ratio of Bs → µ+µ ∼ 3 tension between inclusive and exclusive determination of |Vub| ∼ 3 tension between inclusive and exclusive determination of |Vcb| 2 − 3 anomaly in B → K ⇤µ+µ angular distributions 2 − 3 SM prediction for ✏0/✏ below experimental result ∼ 2.5 lepton flavor non-universality in B → Kµ+µ vs. B → Ke+e ∼ 2.5 non-zero h → ⌧µ

Wolfgang Altmannshofer (UC) Theoretical Advances in Flavor Physics January 14, 2016 18 / 34

(Wolfgang Altmannshofer, Aspen Winter Conference on Particle Physics 2016)

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SLIDE 13

13

Flavor anomalies: Enhanced B→D(*)τν rates

e.

R(D)

0.2 0.3 0.4 0.5 0.6

R(D*)

0.2 0.25 0.3 0.35 0.4 0.45 0.5

BaBar, PRL109,101802(2012) Belle, arXiv:1507.03233 LHCb, arXiv:1506.08614 Average

= 1.0

2

χ ∆

SM prediction ) = 55%

2

χ P(

HFAG

  • Prel. EPS2015

Semileptonic decays with tau leptons are 3.5σ higher than SM predicRon!

Matthias Neubert: Beyond the Higgs Boson

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SLIDE 14

14

Flavor anomalies: Suppressed Bs →Φ μ+μ- branching ratio

LHCb 1506.08777

Branching raRo in region 1 GeV2 < q2 < 6 GeV2 is 3.5σ lower than SM predicRon!

Matthias Neubert: Beyond the Higgs Boson

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SLIDE 15

15

Flavor anomalies: B →K*μ+μ- angular distributions

2.8σ deviaRon in q2 bin between [4, 6] GeV2 (3.0σ in bin [6, 8] GeV2) !

LHCb 1512.04442

Decay

  • bs.

q2 bin SM pred. measurement pull ¯ B0 → ¯ K⇤0µ+µ FL [2, 4.3] 0.81 ± 0.02 0.26 ± 0.19 ATLAS +2.9 ¯ B0 → ¯ K⇤0µ+µ FL [4, 6] 0.74 ± 0.04 0.61 ± 0.06 LHCb +1.9 ¯ B0 → ¯ K⇤0µ+µ S5 [4, 6] −0.33 ± 0.03 −0.15 ± 0.08 LHCb −2.2 ¯ B0 → ¯ K⇤0µ+µ P 0

5

[1.1, 6] −0.44 ± 0.08 −0.05 ± 0.11 LHCb −2.9 ¯ B0 → ¯ K⇤0µ+µ P 0

5

[4, 6] −0.77 ± 0.06 −0.30 ± 0.16 LHCb −2.8 B → K⇤µ+µ 107 dBR

dq2

[4, 6] 0.54 ± 0.08 0.26 ± 0.10 LHCb +2.1 ¯ B0 → ¯ K0µ+µ 108 dBR

dq2

[0.1, 2] 2.71 ± 0.50 1.26 ± 0.56 LHCb +1.9 ¯ B0 → ¯ K0µ+µ 108 dBR

dq2

[16, 23] 0.93 ± 0.12 0.37 ± 0.22 CDF +2.2 Bs → µ+µ 107 dBR

dq2

[1, 6] 0.48 ± 0.06 0.23 ± 0.05 LHCb +3.1

Altmannshofer, Sraub (arXiv:1503:06199)

Matthias Neubert: Beyond the Higgs Boson

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SLIDE 16

16

Flavor anomalies: B →K μ+μ- vs. B →K e+e-

2.6σ hint for a violaRon of lepton flavor universality! LHCb 1406.6482

RK = Γ( ¯ B ! ¯ Kµ+µ−) Γ( ¯ B ! ¯ Ke+e−) = 0.745 +0.090

−0.074 ± 0.036

Matthias Neubert: Beyond the Higgs Boson

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SLIDE 17

17

Flavor anomalies — reason for excitement

Coefficient Best fit 1σ 3σ PullSM CNP

7

−0.02 [−0.04, −0.00] [−0.07, 0.04] 1.1 CNP

9

−1.11 [−1.32, −0.89] [−1.71, −0.40] 4.5 CNP

10

0.58 [0.34, 0.84] [−0.11, 1.41] 2.5 CNP

70

0.02 [−0.01, 0.04] [−0.05, 0.09] 0.7 CNP

90

0.49 [0.21, 0.77] [−0.33, 1.35] 1.8 CNP

100

−0.27 [−0.46, −0.08] [−0.84, 0.28] 1.4 CNP

9

= CNP

10

−0.21 [−0.40, 0.00] [−0.74, 0.55] 1.0 CNP

9

= −CNP

10

−0.69 [−0.88, −0.51] [−1.27, −0.18] 4.1 CNP

9

= −CNP

90

−1.09 [−1.28, −0.88] [−1.62, −0.42] 4.8

The flavor anomalies in rare B-meson decays are:

  • in many cases statistically significant
  • seen by more than one experiment
  • provide a coherent picture when interpreted in

terms of new physics contributions to one or two

  • perators in the effective weak Hamiltonian

Heff = 4GF p 2 VtbV ⇤

ts

X

i

CiOi

Descotes-Genon, Hofer, Matias, Virto (arXiv:1510:04239) O9 = e2 16⇡2(¯ sµPLb)(¯ `µ`), O10 = e2 16⇡2(¯ sµPLb)(¯ `µ5`), O90 = e2 16⇡2(¯ sµPRb)(¯ `µ`), O100 = e2 16⇡2(¯ sµPRb)(¯ `µ5`)

Matthias Neubert: Beyond the Higgs Boson

slide-18
SLIDE 18

18

Flavor anomalies — reason for excitement

Descotes-Genon, Hofer, Matias, Virto (arXiv:1510:04239) O9 = e2 16⇡2(¯ sµPLb)(¯ `µ`), O10 = e2 16⇡2(¯ sµPLb)(¯ `µ5`), O90 = e2 16⇡2(¯ sµPRb)(¯ `µ`), O100 = e2 16⇡2(¯ sµPRb)(¯ `µ5`)

»si» < 4 »si» < 2 »si» < 1

  • 3
  • 2
  • 1

1 2 3

  • 3
  • 2
  • 1

1 2 3 C9

NP

C9'

NP

»si» < 4 »si» < 2 »si» < 1

  • 3
  • 2
  • 1

1 2 3

  • 3
  • 2
  • 1

1 2 3 C9

NP

C10

NP

Matthias Neubert: Beyond the Higgs Boson

The flavor anomalies in rare B-meson decays are:

  • in many cases statistically significant
  • seen by more than one experiment
  • provide a coherent picture when interpreted in

terms of new physics contributions to one or two

  • perators in the effective weak Hamiltonian

Heff = 4GF p 2 VtbV ⇤

ts

X

i

CiOi

slide-19
SLIDE 19

19

A new diboson resonance near 2 TeV in Run-I ?

1.5 2 2.5 3 3.5 Events / 100 GeV

1 −

10 1 10

2

10

3

10

4

10

Data Background model 1.5 TeV EGM W', c = 1 2.0 TeV EGM W', c = 1 2.5 TeV EGM W', c = 1 Significance (stat) Significance (stat + syst)

ATLAS

  • 1

= 8 TeV, 20.3 fb s WZ Selection

[TeV]

jj

m

1.5 2 2.5 3 3.5 Significance 2 − 1 − 1 2 3 1.5 2 2.5 3 3.5 Events / 100 GeV

3 −

10

2 −

10

1 −

10 1 10

2

10

3

10

4

10

Data Background model = 1

PI

M , k/

RS

1.5 TeV Bulk G = 1

PI

M , k/

RS

2.0 TeV Bulk G Significance (stat) Significance (stat + syst)

ATLAS

  • 1

= 8 TeV, 20.3 fb s WW Selection

[TeV]

jj

m

1.5 2 2.5 3 3.5 Significance 2 − 1 − 1 2 3 1.5 2 2.5 3 3.5 Events / 100 GeV

3 −

10

2 −

10

1 −

10 1 10

2

10

3

10

4

10

Data Background model = 1

PI

M , k/

RS

1.5 TeV Bulk G = 1

PI

M , k/

RS

2.0 TeV Bulk G Significance (stat) Significance (stat + syst)

ATLAS

  • 1

= 8 TeV, 20.3 fb s ZZ Selection

[TeV]

jj

m

1.5 2 2.5 3 3.5 Significance 2 − 1 − 1 2 3

Matthias Neubert: Beyond the Higgs Boson

slide-20
SLIDE 20

Lorem ipsum more info 20

A new diphoton resonance near 750 GeV in Run-II ?

[GeV]

X

m 200 400 600 800 1000 1200 1400 1600 1800 Local p-value

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10 1 ATLAS Preliminary

  • 1

= 13 TeV, 3.2 fb s

Observed

σ σ 1 σ 2 σ 3 σ 4

200 400 600 800 1000 1200 1400 1600 Events / 40 GeV

1 −

10 1 10

2

10

3

10

4

10

ATLAS Preliminary

  • 1

= 13 TeV, 3.2 fb s

Data Background-only fit

[GeV]

γ γ

m 200 400 600 800 1000 1200 1400 1600 Data - fitted background 15 − 10 − 5 − 5 10 15

Excess at 750 GeV Local Global NWA 3.6σ 2.0σ Γ ~ 45 GeV 3.9σ 2.3σ

  • Largest excess: MG=750GeV

, local significance 3σ

  • global significance < 1.7σ
slide-21
SLIDE 21

This has created a tsunami of theore3cal papers

  • ver the Christmas holidays …
slide-22
SLIDE 22
slide-23
SLIDE 23

One Leptoquark to Rule them All

Part I: Flavor anomalies

Based on a collaboration with Martin Bauer (arXiv:1511:01900)

slide-24
SLIDE 24

We add a single leptoquark to the Standard Model, with couplings: After rotation to the mass basis, we have: with: UV completion: could be the right-handed sbottom of a split SUSY model, with left-handed couplings derived from the R-parity violating terms in the superpotential (expect )

24

A minimal leptoquark model

Matthias Neubert: Beyond the Higgs Boson

φ ∼ (3, 1)−1/3

Lφ = (Dµ)†Dµ M 2

φ ||2 ghφ |Φ|2||2

+ ¯ QcλLi⌧2L ∗ + ¯ uc

R λReR ∗ + h.c. ,

Lφ 3 ¯ uc

LλL ueeL ∗ ¯

dc

LλL dν⌫L∗+¯

uc

R λR ueeR ∗+h.c.

V T

CKM λL ue = λL d⌫Ue ,

φ |λR| ⌧ |λL| At tree level, this gives rise to e.g.: Will need:

τ φ

c

b

ν

s φ

b

ν

ν

λR

ue ∼

    10−1 − 10−3 λue = V∗

CKMλL dνVPMNS ≈

   

λL

ue = V ∗ CKMλL dνUe

slide-25
SLIDE 25

25

Explanation of the enhanced B→D(*)τν rates

e.

R(D)

0.2 0.3 0.4 0.5 0.6

R(D*)

0.2 0.25 0.3 0.35 0.4 0.45 0.5

BaBar, PRL109,101802(2012) Belle, arXiv:1507.03233 LHCb, arXiv:1506.08614 Average

= 1.0

2

χ ∆

SM prediction ) = 55%

2

χ P(

HFAG

  • Prel. EPS2015

Semileptonic decays with tau leptons are 3.5σ higher than SM predicRon!

Matthias Neubert: Beyond the Higgs Boson

Model-independent operator analysis:

H = 4GF √ 2 Vcb OVL + 1 Λ2 X

i

C(0,00)

i

O(0,00)

i

  • 8
  • 6
  • 4
  • 2

2 4

  • 4
  • 2

2 4 6

C CSL

SL

3s

TeV

  • 2
  • 1

1 2

  • 4
  • 3
  • 2
  • 1

1 2

C¢

VL

VL

3s

TeV

  • 8
  • 6
  • 4
  • 2

2

  • 6
  • 4
  • 2

2 4 6

CSR

≤

CSL

≤

SR SL

1s, 2s, 3s

L = 1 TeV

O

00

SL = (¯

τPLcc)(¯ bcPLν) O

00

SR = (¯

τPRcc)(¯ bcPLν)

Freytsis, Ligeti, Rudermann (arXiv:1506:08896)

slide-26
SLIDE 26

Leptoquark contribution: q2 distribution:

26

Explanation of the enhanced B→D(*)τν rates

Matthias Neubert: Beyond the Higgs Boson

Model-independent operator analysis:

H = 4GF √ 2 Vcb OVL + 1 Λ2 X

i

C(0,00)

i

O(0,00)

i

  • 8
  • 6
  • 4
  • 2

2 4

  • 4
  • 2

2 4 6

C CSL

SL

3s

TeV

  • 2
  • 1

1 2

  • 4
  • 3
  • 2
  • 1

1 2

C¢

VL

VL

3s

TeV

  • 8
  • 6
  • 4
  • 2

2

  • 6
  • 4
  • 2

2 4 6

CSR

≤

CSL

≤

SR SL

1s, 2s, 3s

L = 1 TeV

O

00

SL = (¯

τPLcc)(¯ bcPLν) O

00

SR = (¯

τPRcc)(¯ bcPLν)

Freytsis, Ligeti, Rudermann (arXiv:1506:08896)

λL∗

cτ λL bντ

M 2

φ

≈ 0.35 TeV2 , λR∗

cτ λL bντ

M 2

φ

≈ − 0.03 TeV2

= C00

SR

= C00

SL

4 6 8 10 12

  • 0.1

0.0 0.1 0.2 0.3 0.4 q2 ëGeV2 I1ëGM d Gëd q2

a b c

τ φ c b

ν

slide-27
SLIDE 27

Leptoquark contribution: Interference with SM yields for : with:

27

Bound from B→K(*)νν rates

Matthias Neubert: Beyond the Higgs Boson

Current BaBar bound implies:

s

φ

b

ν ν

L()

eff =

1 2M 2

  • L∗

s⌫iL b⌫j ¯

sLµbL ¯ ⌫i

Lµ⌫j L

R(φ)

ν¯ ν = 1 − 2r

3 Re

  • λLλL†

bs

VtbV ∗

ts

+ r2 3

  • λLλL†

bb

  • λLλL†

ss

  • VtbV ∗

ts

  • 2

Rν¯

ν = Γ/ΓSM

  • λLλL†

bs =

X

i

λL

bνi λL∗ sνi

r = s4

W

2α2 1 X0(xt) m2

W

M 2

φ

≈ 1.91 TeV2 M 2

φ

Rν¯

ν < 4.3 @ 90% CL

− 1.2 TeV2 < 1 M 2

φ

Re

  • λLλL†

bs

VtbV ∗

ts

< 2.3 TeV2 .

slide-28
SLIDE 28

Leptoquark contribution: Correction to SM amplitude: Correction to branching ratio of order 1% or less, below current level of sensitivity Leptoquark contribution: Correction to SM mixing amplitude: Best fit value:

28

Constraints from Bs mixing and B→Xsγ

Matthias Neubert: Beyond the Higgs Boson

s b

φ

ν

φ

b

s

ν

h | | i h | | i C(φ)

Bs e2iφ(φ)

Bs = 1 +

1 g4S0(xt) m2

W

M 2

φ

" LL†

bs

VtbV ∗

ts

#2 p

Bona et al., UTfit collaboration (arXiv:0707.0636)

1 Mφ

  • LL†

bs

VtbV ⇤

ts

⇡ 1.87 + 0.45i TeV

φ

γ

b s ν

! C7γ = CSM

7γ +

✓ v 12Mφ ◆2 λLλL†

bs

VtbV ⇤

ts

slide-29
SLIDE 29

Model-independent operator analysis: with: Take new linear combinations: A good fit is obtained for:

29

Explanation of the RK and B →K*μ+μ- anomalies

Matthias Neubert: Beyond the Higgs Boson

Hiller, Schmaltz (arXiv:1408.1627)

2.6σ hint for a violaRon of lepton flavor universality!

LHCb 1406.6482

| | | Heff = −4 GF √ 2 VtbV ⇤

ts

↵e 4⇡ X

i

Ci(µ)Oi(µ)

O9 = [¯ sµPLb] [¯ `µ`] , O10 = [¯ sµPLb] [¯ `µ5`] ,

O`

LL ⌘ (O` 9 O` 10)/2 ,

O`

LR ⌘ (O` 9 + O` 10)/2 ,

O`

RL ⌘ (O0` 9 O0` 10)/2 ,

O`

RR ⌘ (O0` 9 + O0` 10)/2 ,

Cµ

LL ' 1 ,

Cµ

ij = 0 otherwise

slide-30
SLIDE 30

Model-independent operator analysis: with: Take new linear combinations: A good fit is obtained for:

30

Explanation of the RK and B →K*μ+μ- anomalies

Matthias Neubert: Beyond the Higgs Boson

Hiller, Schmaltz (arXiv:1408.1627)

| | | Heff = −4 GF √ 2 VtbV ⇤

ts

↵e 4⇡ X

i

Ci(µ)Oi(µ)

O9 = [¯ sµPLb] [¯ `µ`] , O10 = [¯ sµPLb] [¯ `µ5`] ,

O`

LL ⌘ (O` 9 O` 10)/2 ,

O`

LR ⌘ (O` 9 + O` 10)/2 ,

O`

RL ⌘ (O0` 9 O0` 10)/2 ,

O`

RR ⌘ (O0` 9 + O0` 10)/2 ,

Cµ

LL ' 1 ,

Cµ

ij = 0 otherwise

Leptoquark contributions: Contributions to Wilson coefficients: Best fit values can be obtained for:

W s b

µ µ φ

ν

t

s b

µ φ

ν

t φ

µ

Cµ(φ)

LL

= m2

t

8παM 2

φ

  • λL

tµ

  • 2 −

1 64πα √ 2 GF M 2

φ

  • λLλL†

bs

VtbV ∗

ts

  • λL†λL

µµ ,

Cµ(φ)

LR

= m2

t

16παM 2

φ

  • λR

tµ

  • 2 

ln M 2

φ

m2

t

− f(xt)

  • −

1 64πα √ 2 GF M 2

φ

  • λLλL†

bs

VtbV ∗

ts

  • λR†λR

µµ ,

s L

uµ

  • 2 +
  • L

cµ

  • 2 +

✓ 1 0.77 ˆ M 2

φ

◆ L

tµ

  • 2 > 2.36 ,
slide-31
SLIDE 31

Without much fine-tuning, our model survives the bounds from:

  • rare D-meson decays such as D→μμ
  • precision data on Z-boson couplings to muons
  • rare decays of the tau lepton, such as τ→μγ
  • …

With a modest right-handed coupling

  • ur model can explain the anomalous magnetic

moment of the muon!

31

Other observables

Matthias Neubert: Beyond the Higgs Boson

|

cµ| ⇠

h |λR

cµ| ⇠ 0.03.

ghtly correlated

µ φ γ t µ φ

γ

t

µ

µ

c c

slide-32
SLIDE 32

32

[GeV]

LQ3

m

200 300 400 500 600 700 800

[pb]

2

) β (1- ×

LQ3

σ

4 −

10

3 −

10

2 −

10

1 −

10 1 10

2

10

3

10

τ

ν b → LQ3LQ3 production, LQ3

ATLAS

All limits at 95% CL

T miss

bb + E = 0) β (

theory

σ ±

2

) β (1 - ×

LQ3

σ expected limit

  • bserved limit

σ 1 ± expected σ 2 ± expected

  • 1

=8 TeV, 20.1 fb s

[GeV]

LQ2

m 300 400 500 600 700 800 900 1000 1100 1200 q) µ → (LQ2 β 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

LQ2LQ2 production

ATLAS

  • 1

= 8 TeV, 20.3 fb s 2-muons + 2-jets All limits at 95% CL jj ν µ jj+ µ µ expected limit

  • bserved limit

σ 1 ± expected σ 2 ± expected

  • 1

= 7 TeV, 1.03 fb s

(d)

[GeV]

LQ2

m 400 600 800 1000 1200 [pb]

2

β ×

LQ2

σ

  • 5

10

  • 4

10

  • 3

10

  • 2

10

  • 1

10 1 10

2

10

ATLAS

  • 1

=8 TeV, 20.3 fb s 2-muons + 2-jets All limits at 95% CL

q µ → LQ2LQ2 production, LQ2

= 1) β (

theory

σ ±

2

β ×

LQ2

σ expected limit

  • bserved limit

σ 1 ± expected σ 2 ± expected

(c)

φ → µc φ → ντb

Matthias Neubert: Beyond the Higgs Boson

Collider bounds

φ → µc

slide-33
SLIDE 33

One Leptoquark to Rule them All

Part II: The diphoton resonance S(750)

Based on a collaboration with Martin Bauer (arXiv:1512:06828)

slide-34
SLIDE 34

34

S φ S φ

5 10 15 20 25 30 35 40

  • ϕ []

ϕ

σ(pp ! S) = π s  αs 192π gφSMS Mφ A0(τφ) 2 Kgg f fgg

  • M 2

S/s

  • (2)

Leptoquark-initiated production of S(750)

L = gφSMφS φ†φ

A new resonance S which is a singlet under the Standard Model gauge group naturally has a portal coupling to the scalar leptoquark This will unavoidably give rise to the production of S in gluon fusion at the LHC: If the branching fraction can be made suffi- ciently large, this can explain the observed rate: S → γγ σ(pp → S) Br(S → γγ) = (4.4 ± 1.1) fb σ(pp → S) [fb]

Matthias Neubert: Beyond the Higgs Boson

φ

slide-35
SLIDE 35

35

Diphoton decay of S(750)

The branching fraction can be further enhanced by increasing the electric charge of , its multiplicity (dark color) or the ratio S → γγ

0.6 0.5 0.4 0.3 0.2 0.1

  • ϕ []

χ [

, Qχ = 1, Nχ = 1 s the 1σ region for , gχS = gφS ss M and fe

Br(S → γγ) gχS/gφS

Matthias Neubert: Beyond the Higgs Boson

χ

L = gχS S ¯ χ χ Γ(S ! ) Γ(S ! gg) = 32N 2

χQ4 χ

Kgg ✓gχS gφS ↵ ↵s ◆2 ⌧φ ⌧χ

  • A1/2(⌧χ)

A0(⌧φ)

  • 2

(

(a) t t1 t2 k1 k2 (e)

χ S

The diphoton decay via leptoquark loops yields too small a branching fractions (~2·10-4) Obtaining an enhanced diphoton rate requires intro- ducing new color-neutral, vector-like fermions : This yields the ratio: If is a member of a multiplet, its neutral partner can be a dark matter candidate! χ χ χ0

slide-36
SLIDE 36

36

Diphoton decay of S(750)

Parameter space in which the experimental rate is reproduced in our model

L = gχS S ¯ χ χ Γ(S ! ) Γ(S ! gg) = 32N 2

χQ4 χ

Kgg ✓gχS gφS ↵ ↵s ◆2 ⌧φ ⌧χ

  • A1/2(⌧χ)

A0(⌧φ)

  • 2

(

(a) t t1 t2 k1 k2 (e)

χ S

  • ϕ []

χ []

σ(pp → S) Br(S → γγ) = (4.4 ± 1.1) fb σ(pp → S) Br(S → γγ)

Qχ = 1 gχS = gφS = 3 Nχ = 1 Nχ = 2

The diphoton decay via leptoquark loops yields too small a branching fractions (~2·10-4) Obtaining an enhanced diphoton rate requires intro- ducing new color-neutral, vector-like fermions : This yields the ratio: If is a member of a multiplet, its neutral partner can be a dark matter candidate!

Matthias Neubert: Beyond the Higgs Boson

χ χ χ0

slide-37
SLIDE 37
slide-38
SLIDE 38

Outlook

slide-39
SLIDE 39

One the verge of more discoveries?

Discovery of the Higgs boson has opened a new era in exploration of fundamental structures of Nature Growing number of anomalies — both at the precision frontier and the energy frontier — give us confidence that the Standard Model may soon be cracked

slide-40
SLIDE 40

Thank you!

ERC Advanced Grant (EFT4LHC) An Effective Field Theory Assault on the Zeptometer Scale: Exploring the Origins of Flavor and Electroweak Symmetry Breaking