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Challenges for particle physics from strings Michael Ratz XVI - - PowerPoint PPT Presentation

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Challenges for particle physics from strings Michael Ratz XVI Mexican Workshop on Particles and Fields Puerto Vallarta, October 27, 2017 Based on collaborations with: F. Brmmer, W. Buchmller, M.C. Chen , M. Fallbacher, K. Hamaguchi, R.

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SLIDE 1

Challenges for particle physics from strings

Michael Ratz XVI Mexican Workshop on Particles and Fields Puerto Vallarta, October 27, 2017

Based on collaborations with:

  • F. Brümmer, W. Buchmüller, M.–C. Chen, M. Fallbacher, K. Hamaguchi,
  • R. Kappl, T. Kobayashi, O. Lebedev, H.M. Lee, A. Mütter, H.P

. Nilles,

  • B. Petersen, F. Plöger, S. Raby, S. Ramos–Sánchez, G. Ross,
  • R. Schieren, K. Schmidt–Hoberg, A. Trautner, V. Takhistov,

P . Vaudrevange & A. Wingerter

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SLIDE 2 Challenges for particle physics from strings Introduction String model building

String model building

☞ Physicists have been playing with strings for quite some time

Michael Ratz, UC Irvine Puerto Vallarta 2017 2/ 21
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SLIDE 3 Challenges for particle physics from strings Introduction String model building

String model building

☞ Physicists have been playing with strings for quite some time ☞ String theories are perturbative limits of some mysterious theory type I type IIB type IIA 11D SUGRA heterotic E heterotic O

Michael Ratz, UC Irvine Puerto Vallarta 2017 2/ 21
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SLIDE 4 Challenges for particle physics from strings Introduction String model building

String model building

☞ Physicists have been playing with strings for quite some time ☞ String theories are perturbative limits of some mysterious theory which we are ultimatelyinterested in ☞ String theory is believed to provide us with a consistent description

  • f quantum gravity
Michael Ratz, UC Irvine Puerto Vallarta 2017 2/ 21
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SLIDE 5 Challenges for particle physics from strings Introduction String model building

String model building

☞ Physicists have been playing with strings for quite some time ☞ String theories are perturbative limits of some mysterious theory which we are ultimatelyinterested in ☞ String theory is believed to provide us with a consistent description

  • f quantum gravity

☞ Ultimately, it is hoped that string/M–theory provides us with a theory

  • f everything
Michael Ratz, UC Irvine Puerto Vallarta 2017 2/ 21
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SLIDE 6 Challenges for particle physics from strings Introduction String model building

String model building

☞ Physicists have been playing with strings for quite some time ☞ String theories are perturbative limits of some mysterious theory which we are ultimatelyinterested in ☞ String theory is believed to provide us with a consistent description

  • f quantum gravity

☞ Ultimately, it is hoped that string/M–theory provides us with a theory

  • f everything

☞ Superstring theory requires 10 space–time dimensions

Michael Ratz, UC Irvine Puerto Vallarta 2017 2/ 21
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SLIDE 7 Challenges for particle physics from strings Introduction String model building

String model building

☞ Physicists have been playing with strings for quite some time ☞ String theories are perturbative limits of some mysterious theory which we are ultimatelyinterested in ☞ String theory is believed to provide us with a consistent description

  • f quantum gravity

☞ Ultimately, it is hoped that string/M–theory provides us with a theory

  • f everything

☞ Superstring theory requires 10 space–time dimensions ➥ 6 dimensions need to be compact

Michael Ratz, UC Irvine Puerto Vallarta 2017 2/ 21
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SLIDE 8 Challenges for particle physics from strings Introduction String compactifications

String compactifications

☞ Violin: needs to be constructed in such a way that the

  • scillating strings produce the

right sounds

Michael Ratz, UC Irvine Puerto Vallarta 2017 3/ 21
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SLIDE 9 Challenges for particle physics from strings Introduction String compactifications

String compactifications

☞ Violin: needs to be constructed in such a way that the

  • scillating strings produce the

right sounds ☞ String compactification: twist the string in such a way that the excitations carry the quantum numbers of the standard model particles

Michael Ratz, UC Irvine Puerto Vallarta 2017 3/ 21
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SLIDE 10 Challenges for particle physics from strings Introduction From strings to the real world?

From strings to the real world?

☞ Many popular attempts to connect strings with observation:

  • heterotic orbifolds
  • intersecting D–branes
  • Calabi–Yau compactifications
  • F–theory
  • . . .
Michael Ratz, UC Irvine Puerto Vallarta 2017 4/ 21
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SLIDE 11 Challenges for particle physics from strings Introduction From strings to the real world?

From strings to the real world?

☞ Many popular attempts to connect strings with observation:

  • heterotic orbifolds
  • intersecting D–branes
  • Calabi–Yau compactifications
  • F–theory
  • . . .

☞ Only the first two are true string models (but the others are believed to relate to string compactifications)

Michael Ratz, UC Irvine Puerto Vallarta 2017 4/ 21
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SLIDE 12 Challenges for particle physics from strings Introduction From strings to the real world?

From strings to the real world?

☞ Many popular attempts to connect strings with observation:

  • heterotic orbifolds
  • intersecting D–branes
  • Calabi–Yau compactifications
  • F–theory
  • . . .

☞ Only the first two are true string models (but the others are believed to relate to string compactifications) main theme of the rest of this talk:

  • rbifold compactifications of the heterotic string
Michael Ratz, UC Irvine Puerto Vallarta 2017 4/ 21
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SLIDE 13 Challenges for particle physics from strings Introduction From strings to the real world?

Where do we stand?

☞ Free fermionic construction: 107 standard–like models (all different???)

e.g. Faraggi, Rizos & Sonmez (2017) Michael Ratz, UC Irvine Puerto Vallarta 2017 5/ 21
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SLIDE 14 Challenges for particle physics from strings Introduction From strings to the real world?

Where do we stand?

☞ Free fermionic construction: 107 standard–like models

e.g. Faraggi, Rizos & Sonmez (2017)

☞ F–theory

Buchmüller, Dierigl, Oehlmann & Ruehle (2017b)

“However, despite the remarkable progress in F–theory model building in recent years, a number of important conceptual and phenomenological questions still remain open. In fact, to the best of our knowledge, at present there is no fully satisfactory F–theory GUT model, which would have to account for symmetry breaking to the standard model gauge group, the matter content of the (supersymmetric) standard model, doublet–triplet splitting, sufficiently suppressed proton decay, supersymmetry breaking and semi–realistic quark and lepton mass matrices.”

Michael Ratz, UC Irvine Puerto Vallarta 2017 5/ 21
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SLIDE 15 Challenges for particle physics from strings Introduction From strings to the real world?

Where do we stand?

☞ Free fermionic construction: 107 standard–like models

e.g. Faraggi, Rizos & Sonmez (2017)

☞ F–theory ☞ D–brane models: contradicting statements in the literature

Michael Ratz, UC Irvine Puerto Vallarta 2017 5/ 21
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SLIDE 16 Challenges for particle physics from strings Introduction From strings to the real world?

Where do we stand?

☞ Free fermionic construction: 107 standard–like models

e.g. Faraggi, Rizos & Sonmez (2017)

☞ F–theory ☞ D–brane models: contradicting statements in the literature ☞ Smooth Calabi–Yau compactifications: 2000 standard–like models

e.g. Anderson, Constantin, Gray, Lukas & Palti (2014) Michael Ratz, UC Irvine Puerto Vallarta 2017 5/ 21
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SLIDE 17 Challenges for particle physics from strings Introduction From strings to the real world?

Where do we stand?

☞ Free fermionic construction: 107 standard–like models

e.g. Faraggi, Rizos & Sonmez (2017)

☞ F–theory ☞ D–brane models: contradicting statements in the literature ☞ Smooth Calabi–Yau compactifications: 2000 standard–like models

e.g. Anderson, Constantin, Gray, Lukas & Palti (2014)

☞ Heterotic mini–landscape search: O(105) standard–like models

Lebedev, Nilles, Raby, Ramos-Sánchez, M.R., Vaudrevange & Wingerter (2007a,c) Michael Ratz, UC Irvine Puerto Vallarta 2017 5/ 21
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SLIDE 18 Challenges for particle physics from strings Introduction From strings to the real world?

Where do we stand?

☞ Free fermionic construction: 107 standard–like models

e.g. Faraggi, Rizos & Sonmez (2017)

☞ F–theory ☞ D–brane models: contradicting statements in the literature ☞ Smooth Calabi–Yau compactifications: 2000 standard–like models

e.g. Anderson, Constantin, Gray, Lukas & Palti (2014)

☞ Heterotic mini–landscape search: O(105) standard–like models

Lebedev, Nilles, Raby, Ramos-Sánchez, M.R., Vaudrevange & Wingerter (2007a,c)

☞ Many more models can be found with the ‘orbifolder’

Nilles, Ramos-Sánchez, Vaudrevange & Wingerter (2012) Michael Ratz, UC Irvine Puerto Vallarta 2017 5/ 21
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SLIDE 19 Challenges for particle physics from strings Introduction From strings to the real world?

Where do we stand?

☞ Free fermionic construction: 107 standard–like models

e.g. Faraggi, Rizos & Sonmez (2017)

☞ F–theory ☞ D–brane models: contradicting statements in the literature ☞ Smooth Calabi–Yau compactifications: 2000 standard–like models

e.g. Anderson, Constantin, Gray, Lukas & Palti (2014)

☞ Heterotic mini–landscape search: O(105) standard–like models

Lebedev, Nilles, Raby, Ramos-Sánchez, M.R., Vaudrevange & Wingerter (2007a,c)

☞ Many more models can be found with the ‘orbifolder’

Nilles, Ramos-Sánchez, Vaudrevange & Wingerter (2012)

☞ Complete classification of heterotic orbifold geometries

Fischer, M.R., Torrado & Vaudrevange (2013b); Fischer, Ramos-Sánchez & Vaudrevange (2013a) Michael Ratz, UC Irvine Puerto Vallarta 2017 5/ 21
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SLIDE 20 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

☞ Starting point: torus

Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 21 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

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SLIDE 22 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

❩2

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SLIDE 23 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

❩2

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SLIDE 24 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 25 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 26 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 27 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 28 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 29 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 30 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 31 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 32 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 33 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 34 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 35 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 36 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 37 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 38 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 39 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 40 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 41 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 42 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-43
SLIDE 43 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 44 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 45 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 46 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-47
SLIDE 47 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-48
SLIDE 48 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-49
SLIDE 49 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-50
SLIDE 50 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-51
SLIDE 51 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-52
SLIDE 52 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-53
SLIDE 53 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-54
SLIDE 54 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-55
SLIDE 55 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-56
SLIDE 56 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-57
SLIDE 57 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-58
SLIDE 58 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-59
SLIDE 59 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-60
SLIDE 60 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-61
SLIDE 61 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-62
SLIDE 62 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-63
SLIDE 63 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-64
SLIDE 64 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 65 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 66 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 67 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 68 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 69 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 70 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
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SLIDE 71 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

❩2 orbifold pillow

back Michael Ratz, UC Irvine Puerto Vallarta 2017 6/ 21
slide-72
SLIDE 72 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

What is an orbifold?

bcb bcb bcb bcb

☞ An orbifold is a space which is smooth/flat everywhere except for special (orbifold fixed) points

Michael Ratz, UC Irvine Puerto Vallarta 2017 7/ 21
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SLIDE 73 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

What is an orbifold?

bcb bcb bcb bcb

Gbl Gbr Gtl Gtr

G

bcb bcb bcb bcb

☞ An orbifold is a space which is smooth/flat everywhere except for special (orbifold fixed) points ☞ ‘Bulk’ gauge symmetry G is broken to (different) subgroups (local GUTs) at the fixed points

Michael Ratz, UC Irvine Puerto Vallarta 2017 7/ 21
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SLIDE 74 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

What is an orbifold?

bcb bcb bcb bcb

Gbl Gbr Gtl Gtr

G

bcb bcb bcb bcb

☞ An orbifold is a space which is smooth/flat everywhere except for special (orbifold fixed) points ☞ ‘Bulk’ gauge symmetry G is broken to (different) subgroups (local GUTs) at the fixed points ☞ Low–energy gauge group : Glow−energy = Gbl ∩ Gbr ∩ Gtl ∩ Gtr

Michael Ratz, UC Irvine Puerto Vallarta 2017 7/ 21
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SLIDE 75 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

Strings on orbifolds

heterotic string field theory untwisted sector = strings closed on the torus extra compo- nents of gauge fields ‘twisted’ sectors = strings which are only closed on the orbifold ‘brane fields’

(hard to understand in field–theoretical framework)

bcb bcb bcb bcb

☞ (‘Brane’) Fields living at a fixed point with a certain symmetry appear as complete multiplet of that symmetry

Michael Ratz, UC Irvine Puerto Vallarta 2017 8/ 21
slide-76
SLIDE 76 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

Strings on orbifolds

heterotic string field theory untwisted sector = strings closed on the torus extra compo- nents of gauge fields ‘twisted’ sectors = strings which are only closed on the orbifold ‘brane fields’

(hard to understand in field–theoretical framework)

bcb bcb bcb bcb

☞ (‘Brane’) Fields living at a fixed point with a certain symmetry appear as complete multiplet of that symmetry ➥ E.g. if the electron lives at a point with SO(10) symmetry also u and d quarks live there

Michael Ratz, UC Irvine Puerto Vallarta 2017 8/ 21
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SLIDE 77 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

String compactifications with local SO(10) GUTs

4D space–time

Michael Ratz, UC Irvine Puerto Vallarta 2017 9/ 21
slide-78
SLIDE 78 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

String compactifications with local SO(10) GUTs

4D space–time

6D internal space

Michael Ratz, UC Irvine Puerto Vallarta 2017 9/ 21
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SLIDE 79 Challenges for particle physics from strings Heterotic orbifolds What is an orbifold?

String compactifications with local SO(10) GUTs

4D space–time

6D internal space

b c

b

SO(10) 16

Michael Ratz, UC Irvine Puerto Vallarta 2017 9/ 21
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SLIDE 80 Challenges for particle physics from strings Heterotic orbifolds Results & “stringy surprises”

The mini–landscape search

Michael Ratz, UC Irvine Puerto Vallarta 2017 10/ 21
slide-81
SLIDE 81 Challenges for particle physics from strings Heterotic orbifolds Results & “stringy surprises”

Results

➊ 3 × 16 + Higgs + nothing

❩

No exotics

Lebedev, Nilles, Raby, Ramos-Sánchez, M.R., Vau- drevange & Wingerter (2007b) Michael Ratz, UC Irvine Puerto Vallarta 2017 11/ 21
slide-82
SLIDE 82 Challenges for particle physics from strings Heterotic orbifolds Results & “stringy surprises”

Results

➊ 3 × 16 + Higgs + nothing ➋ SU(3) × SU(2) × U(1)Y × Ghid

❩

Lebedev, Nilles, Raby, Ramos-Sánchez, M.R., Vau- drevange & Wingerter (2007b) Michael Ratz, UC Irvine Puerto Vallarta 2017 11/ 21
slide-83
SLIDE 83 Challenges for particle physics from strings Heterotic orbifolds Results & “stringy surprises”

Results

➊ 3 × 16 + Higgs + nothing ➋ SU(3) × SU(2) × U(1)Y × Ghid ➌ unification

precision gauge unification (PGU) from non–local GUT breaking ❩

3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 log10ΜGeV 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 Αi

Α3 Α2 Α1

Raby, M.R. & Schmidt-Hoberg (2010); Krippendorf, Nilles, M.R. & Winkler (2013) Michael Ratz, UC Irvine Puerto Vallarta 2017 11/ 21
slide-84
SLIDE 84 Challenges for particle physics from strings Heterotic orbifolds Results & “stringy surprises”

Results

❩

Michael Ratz, UC Irvine Puerto Vallarta 2017 11/ 21
slide-85
SLIDE 85 Challenges for particle physics from strings Heterotic orbifolds Results & “stringy surprises”

Results

➊ 3 × 16 + Higgs + nothing ➋ SU(3) × SU(2) × U(1)Y × Ghid ➌ unification ➍ R parity & ❩R

4

✟✟✟ ✟ ❍❍❍ ❍

u d d

✟✟✟ ❍❍❍

q d ℓ

✟✟ ✟ ❍❍ ❍

ℓ ℓ e

✟✟✟ ❍❍❍

ℓ Hu

proton long–lived DM stable

Lebedev, Nilles, Raby, Ramos-Sánchez, M.R., Vau- drevange & Wingerter (2007c); Kappl, Petersen, Raby, M.R., Schieren & Vaudrevange (2011) Michael Ratz, UC Irvine Puerto Vallarta 2017 11/ 21
slide-86
SLIDE 86 Challenges for particle physics from strings Heterotic orbifolds Results & “stringy surprises”

Results

➊ 3 × 16 + Higgs + nothing ➋ SU(3) × SU(2) × U(1)Y × Ghid ➌ unification ➍ R parity & ❩R

4

➎ see–saw

suppressed ν masses

Buchmüller, Hamaguchi, Lebedev, Ramos-Sánchez & M.R. (2007) Michael Ratz, UC Irvine Puerto Vallarta 2017 11/ 21
slide-87
SLIDE 87 Challenges for particle physics from strings Heterotic orbifolds Results & “stringy surprises”

Results

➊ 3 × 16 + Higgs + nothing ➋ SU(3) × SU(2) × U(1)Y × Ghid ➌ unification ➍ R parity & ❩R

4

➎ see–saw ➏ yt ≃ g @ MGUT & potentially

realistic flavor structures à la Froggatt-Nielsen

3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 log10ΜGeV 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 Αi

Α3 Α2 Α1 Αt realistic top mass

Hosteins, Kappl, M.R. & Schmidt-Hoberg (2009) Michael Ratz, UC Irvine Puerto Vallarta 2017 11/ 21
slide-88
SLIDE 88 Challenges for particle physics from strings Heterotic orbifolds Results & “stringy surprises”

Results

➊ 3 × 16 + Higgs + nothing ➋ SU(3) × SU(2) × U(1)Y × Ghid ➌ unification ➍ R parity & ❩R

4

➎ see–saw ➏ yt ≃ g @ MGUT & potentially

realistic flavor structures à la Froggatt-Nielsen

➐ ‘realistic’ hidden sector

scale of hidden sector strong dynamics is consistent with TeV–scale soft masses

Lebedev, Nilles, Raby, Ramos-Sánchez, M.R., Vau- drevange & Wingerter (2007b) Michael Ratz, UC Irvine Puerto Vallarta 2017 11/ 21
slide-89
SLIDE 89 Challenges for particle physics from strings Heterotic orbifolds Results & “stringy surprises”

Results & “stringy surprises”

➊ 3 × 16 + Higgs + nothing ➋ SU(3) × SU(2) × U(1)Y × Ghid ➌ unification ➍ R parity & ❩R

4

➎ see–saw ➏ yt ≃ g @ MGUT & potentially

realistic flavor structures à la Froggatt-Nielsen

➐ ‘realistic’ hidden sector ➑ solution to the µ problem

µ ∼ W W ≪ 1 from approximate U(1)R symmetries light Higgs

Kappl, Nilles, Ramos-Sánchez, M.R., Schmidt-Hoberg & Vaudrevange (2009); Brümmer, Kappl, M.R. & Schmidt-Hoberg (2010) Michael Ratz, UC Irvine Puerto Vallarta 2017 11/ 21
slide-90
SLIDE 90 Challenges for particle physics from strings Heterotic orbifolds Results & “stringy surprises”

Results & “stringy surprises”

➊ 3 × 16 + Higgs + nothing ➋ SU(3) × SU(2) × U(1)Y × Ghid ➌ unification ➍ R parity & ❩R

4

➎ see–saw ➏ yt ≃ g @ MGUT & potentially

realistic flavor structures à la Froggatt-Nielsen

➐ ‘realistic’ hidden sector ➑ solution to the µ problem

                   that’s what we searched for. . .                              . . . that’s what we got ‘for free’ “stringy surprises”

Michael Ratz, UC Irvine Puerto Vallarta 2017 11/ 21
slide-91
SLIDE 91 Challenges for particle physics from strings Open questions & challenges

Open questions & challenges

Michael Ratz, UC Irvine Puerto Vallarta 2017 12/ 21
slide-92
SLIDE 92 Challenges for particle physics from strings Open questions & challenges Issue 1: the ‘Landscape’

Issue 1: the ‘Landscape’

Michael Ratz, UC Irvine Puerto Vallarta 2017 13/ 21
slide-93
SLIDE 93 Challenges for particle physics from strings Open questions & challenges Issue 1: the ‘Landscape’

Issue 1: the ‘Landscape’

PRO ☞ Hard to disprove

Michael Ratz, UC Irvine Puerto Vallarta 2017 13/ 21
slide-94
SLIDE 94 Challenges for particle physics from strings Open questions & challenges Issue 1: the ‘Landscape’

Issue 1: the ‘Landscape’

PRO ☞ Hard to disprove ☞ Seems to have suggested the

  • bserved cosmological constant
Michael Ratz, UC Irvine Puerto Vallarta 2017 13/ 21
slide-95
SLIDE 95 Challenges for particle physics from strings Open questions & challenges Issue 1: the ‘Landscape’

Issue 1: the ‘Landscape’

PRO ☞ Hard to disprove ☞ Seems to have suggested the

  • bserved cosmological constant
Michael Ratz, UC Irvine Puerto Vallarta 2017 13/ 21
slide-96
SLIDE 96 Challenges for particle physics from strings Open questions & challenges Issue 1: the ‘Landscape’

Issue 1: the ‘Landscape’

PRO ☞ Hard to disprove ☞ Seems to have suggested the

  • bserved cosmological constant

☞ Extremely convenient CONTRA ☞ There are observations that do not have an anthropic explanation such as θQCD

see, however, Kaloper & Terning (2017) Michael Ratz, UC Irvine Puerto Vallarta 2017 13/ 21
slide-97
SLIDE 97 Challenges for particle physics from strings Open questions & challenges Issue 1: the ‘Landscape’

Issue 1: the ‘Landscape’

PRO ☞ Hard to disprove ☞ Seems to have suggested the

  • bserved cosmological constant

☞ Extremely convenient CONTRA ☞ There are observations that do not have an anthropic explanation such as θQCD

see, however, Kaloper & Terning (2017)

☞ A new version of “why now problem”: why did questions in the

  • ld days have non–anthropic

explanations and only the newer problems not?

Michael Ratz, UC Irvine Puerto Vallarta 2017 13/ 21
slide-98
SLIDE 98 Challenges for particle physics from strings Open questions & challenges Issue 1: the ‘Landscape’

Issue 1: the ‘Landscape’

PRO ☞ Hard to disprove ☞ Seems to have suggested the

  • bserved cosmological constant

☞ Extremely convenient CONTRA ☞ There are observations that do not have an anthropic explanation such as θQCD

see, however, Kaloper & Terning (2017)

☞ A new version of “why now problem”: why did questions in the

  • ld days have non–anthropic

explanations and only the newer problems not? Note: Even if one believes in the landscape, one still needs to understand the string models, i.e. construct at least some of them explicitly

Michael Ratz, UC Irvine Puerto Vallarta 2017 13/ 21
slide-99
SLIDE 99 Challenges for particle physics from strings Open questions & challenges Issue 2: the ‘Swampland’

Issue 2: the ‘Swampland’

☞ Swampland: constructions which resemble string constructions but are not

Vafa (2005) Michael Ratz, UC Irvine Puerto Vallarta 2017 14/ 21
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SLIDE 100 Challenges for particle physics from strings Open questions & challenges Issue 2: the ‘Swampland’

Issue 2: the ‘Swampland’

☞ Swampland: constructions which resemble string constructions but are not

Vafa (2005)

☞ Example 1:

Groot Nibbelink, Loukas, Ruehle & Vaudrevange (2015)
  • infinite sets of models allowed by the usual consistency conditions of

Calabi–Yau model building by adding fluxes. . .

  • . . . but these models would have an arbitrarily large number of

massless states and cannot be UV complete

Michael Ratz, UC Irvine Puerto Vallarta 2017 14/ 21
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SLIDE 101 Challenges for particle physics from strings Open questions & challenges Issue 2: the ‘Swampland’

Issue 2: the ‘Swampland’

☞ Swampland: constructions which resemble string constructions but are not

Vafa (2005)

☞ Example 1: constraints on fluxes??? ☞ Example 2:

Blaszczyk, Groot Nibbelink, M.R., Ruehle, Trapletti, et al. (2010)
  • freely acting Wilson lines are subject to modular invariance contraints

in orbifolds

Michael Ratz, UC Irvine Puerto Vallarta 2017 14/ 21
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SLIDE 102 Challenges for particle physics from strings Open questions & challenges Issue 2: the ‘Swampland’

Issue 2: the ‘Swampland’

☞ Swampland: constructions which resemble string constructions but are not

Vafa (2005)

☞ Example 1: constraints on fluxes??? ☞ Example 2:

Blaszczyk, Groot Nibbelink, M.R., Ruehle, Trapletti, et al. (2010)
  • freely acting Wilson lines are subject to modular invariance contraints

in orbifolds

e.g. Groot Nibbelink, Klevers, Plöger, Trapletti & Vaudrevange (2008)
  • . . . these orbifolds can be blown up to Calabi–Yau manifolds. . .
Michael Ratz, UC Irvine Puerto Vallarta 2017 14/ 21
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SLIDE 103 Challenges for particle physics from strings Open questions & challenges Issue 2: the ‘Swampland’

Issue 2: the ‘Swampland’

☞ Swampland: constructions which resemble string constructions but are not

Vafa (2005)

☞ Example 1: constraints on fluxes??? ☞ Example 2:

Blaszczyk, Groot Nibbelink, M.R., Ruehle, Trapletti, et al. (2010)
  • freely acting Wilson lines are subject to modular invariance contraints

in orbifolds

e.g. Groot Nibbelink, Klevers, Plöger, Trapletti & Vaudrevange (2008)
  • . . . these orbifolds can be blown up to Calabi–Yau manifolds. . .
  • . . . but in Calabi–Yau model building there appear to be no analogous

constraints

Michael Ratz, UC Irvine Puerto Vallarta 2017 14/ 21
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SLIDE 104 Challenges for particle physics from strings Open questions & challenges Issue 2: the ‘Swampland’

Issue 2: the ‘Swampland’

☞ Swampland: constructions which resemble string constructions but are not

Vafa (2005)

☞ Example 1: constraints on fluxes??? ☞ Example 2: constraints on Wilson lines? ☞ Question: how many of the Calabi–Yau and F–theory models are truly consistent string models? ☞ Question: are there additional consistency conditions at the level of field theory that ensure that a given model has a stringy completion? ☞ . . . obviously globally consistent string compactifications fulfill this . . .

Michael Ratz, UC Irvine Puerto Vallarta 2017 14/ 21
slide-105
SLIDE 105 Challenges for particle physics from strings Open questions & challenges Issue 3: Did we already find the standard model?

Issue 3: Did we already find the standard model?

☞ There is a number of known constructions that have not yet been ruled out

Michael Ratz, UC Irvine Puerto Vallarta 2017 15/ 21
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SLIDE 106 Challenges for particle physics from strings Open questions & challenges Issue 3: Did we already find the standard model?

Issue 3: Did we already find the standard model?

☞ There is a number of known constructions that have not yet been ruled out ☞ However, we are still very far from calculating, say, the electron mass

Michael Ratz, UC Irvine Puerto Vallarta 2017 15/ 21
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SLIDE 107 Challenges for particle physics from strings Open questions & challenges Issue 3: Did we already find the standard model?

Issue 3: Did we already find the standard model?

☞ There is a number of known constructions that have not yet been ruled out ☞ However, we are still very far from calculating, say, the electron mass ☞ Would need to have better understanding of

1 Kähler potential Bailin & Love (1992) . . . Olguin-Trejo & Ramos-Sánchez (2017) see talk by Yessenia Olguin–Trejo Michael Ratz, UC Irvine Puerto Vallarta 2017 15/ 21
slide-108
SLIDE 108 Challenges for particle physics from strings Open questions & challenges Issue 3: Did we already find the standard model?

Issue 3: Did we already find the standard model?

☞ There is a number of known constructions that have not yet been ruled out ☞ However, we are still very far from calculating, say, the electron mass ☞ Would need to have better understanding of

1 Kähler potential Bailin & Love (1992) . . . Olguin-Trejo & Ramos-Sánchez (2017) see talk by Yessenia Olguin–Trejo 2 Couplings at higher orders Michael Ratz, UC Irvine Puerto Vallarta 2017 15/ 21
slide-109
SLIDE 109 Challenges for particle physics from strings Open questions & challenges Issue 3: Did we already find the standard model?

Issue 3: Did we already find the standard model?

☞ There is a number of known constructions that have not yet been ruled out ☞ However, we are still very far from calculating, say, the electron mass ☞ Would need to have better understanding of

1 Kähler potential Bailin & Love (1992) . . . Olguin-Trejo & Ramos-Sánchez (2017) see talk by Yessenia Olguin–Trejo 2 Couplings at higher orders 3 Supersymmetry breaking Michael Ratz, UC Irvine Puerto Vallarta 2017 15/ 21
slide-110
SLIDE 110 Challenges for particle physics from strings Open questions & challenges Issue 4: Where is supersymmetry?

Issue 4: Where is supersymmetry?

☞ So far no sign of supersymmetry at the LHC

Michael Ratz, UC Irvine Puerto Vallarta 2017 16/ 21
slide-111
SLIDE 111 Challenges for particle physics from strings Open questions & challenges Issue 4: Where is supersymmetry?

Issue 4: Where is supersymmetry?

☞ So far no sign of supersymmetry at the LHC ☞ Should one focus on nonsupersymmetric string compactifications?

Kachru, Kumar & Silverstein (1999); Dienes (2001); Angelantonj & Antoniadis (2004); Dudas & Timirgaziu (2004); Dienes (2006) Gato-Rivera & Schellekens (2007); Faraggi & Tsulaia (2008); Blaszczyk, Groot Nibbelink, Loukas & Ramos-Sánchez (2014) Angelantonj, Florakis & Tsulaia (2014); Abel, Dienes & Mavroudi (2015) ) Michael Ratz, UC Irvine Puerto Vallarta 2017 16/ 21
slide-112
SLIDE 112 Challenges for particle physics from strings Open questions & challenges Issue 4: Where is supersymmetry?

Issue 4: Where is supersymmetry?

☞ So far no sign of supersymmetry at the LHC ☞ Should one focus on nonsupersymmetric string compactifications?

Kachru, Kumar & Silverstein (1999); Dienes (2001); Angelantonj & Antoniadis (2004); Dudas & Timirgaziu (2004); Dienes (2006) Gato-Rivera & Schellekens (2007); Faraggi & Tsulaia (2008); Blaszczyk, Groot Nibbelink, Loukas & Ramos-Sánchez (2014) Angelantonj, Florakis & Tsulaia (2014); Abel, Dienes & Mavroudi (2015) )

☞ New ways to address the hierarchy problem?

Buchmüller, Dierigl, Dudas & Schweizer (2017a) Michael Ratz, UC Irvine Puerto Vallarta 2017 16/ 21
slide-113
SLIDE 113 Challenges for particle physics from strings Open questions & challenges Issue 4: Where is supersymmetry?

Issue 4: Where is supersymmetry?

☞ So far no sign of supersymmetry at the LHC ☞ Should one focus on nonsupersymmetric string compactifications?

Kachru, Kumar & Silverstein (1999); Dienes (2001); Angelantonj & Antoniadis (2004); Dudas & Timirgaziu (2004); Dienes (2006) Gato-Rivera & Schellekens (2007); Faraggi & Tsulaia (2008); Blaszczyk, Groot Nibbelink, Loukas & Ramos-Sánchez (2014) Angelantonj, Florakis & Tsulaia (2014); Abel, Dienes & Mavroudi (2015) )

☞ New ways to address the hierarchy problem?

Buchmüller, Dierigl, Dudas & Schweizer (2017a)

. . . but why has this been missed in the bottom–up approach?

Michael Ratz, UC Irvine Puerto Vallarta 2017 16/ 21
slide-114
SLIDE 114 Challenges for particle physics from strings Open questions & challenges Issue 4: Where is supersymmetry?

Issue 4: Where is supersymmetry?

☞ So far no sign of supersymmetry at the LHC ☞ Should one focus on nonsupersymmetric string compactifications?

Kachru, Kumar & Silverstein (1999); Dienes (2001); Angelantonj & Antoniadis (2004); Dudas & Timirgaziu (2004); Dienes (2006) Gato-Rivera & Schellekens (2007); Faraggi & Tsulaia (2008); Blaszczyk, Groot Nibbelink, Loukas & Ramos-Sánchez (2014) Angelantonj, Florakis & Tsulaia (2014); Abel, Dienes & Mavroudi (2015) )

☞ New ways to address the hierarchy problem?

Buchmüller, Dierigl, Dudas & Schweizer (2017a)

. . . but why has this been missed in the bottom–up approach? ☞ Tension between non–supersymmetric compactifications and a small cosmological constant

Groot Nibbelink, Loukas, Mütter, Parr & Vaudrevange (2017) Michael Ratz, UC Irvine Puerto Vallarta 2017 16/ 21
slide-115
SLIDE 115 Challenges for particle physics from strings Open questions & challenges Issue 5: Moduli stabilization

Issue 5: Moduli stabilization

☞ Explicit string models typically have many scalar fields which have a flat potential at the classical level

Michael Ratz, UC Irvine Puerto Vallarta 2017 17/ 21
slide-116
SLIDE 116 Challenges for particle physics from strings Open questions & challenges Issue 5: Moduli stabilization

Issue 5: Moduli stabilization

☞ Explicit string models typically have many scalar fields which have a flat potential at the classical level ☞ Nontrivial potential often gets induced nonperturbatively

Michael Ratz, UC Irvine Puerto Vallarta 2017 17/ 21
slide-117
SLIDE 117 Challenges for particle physics from strings Open questions & challenges Issue 5: Moduli stabilization

Issue 5: Moduli stabilization

☞ Explicit string models typically have many scalar fields which have a flat potential at the classical level ☞ Nontrivial potential often gets induced nonperturbatively ☞ Challenge: enumerate and compute the local minima

Michael Ratz, UC Irvine Puerto Vallarta 2017 17/ 21
slide-118
SLIDE 118 Challenges for particle physics from strings Open questions & challenges Issue 5: Moduli stabilization

Issue 5: Moduli stabilization

☞ Explicit string models typically have many scalar fields which have a flat potential at the classical level ☞ Nontrivial potential often gets induced nonperturbatively ☞ Challenge: enumerate and compute the local minima ☞ Moduli VEVs determine couplings of the low–energy effective theory LQCD

very

− − − − →

hard

proton mass string model

much

− − − − − − →

harder

electron mass

Michael Ratz, UC Irvine Puerto Vallarta 2017 17/ 21
slide-119
SLIDE 119 Challenges for particle physics from strings Open questions & challenges Issue 6: potential absence of smoking gun signatures

Issue 6: potential absence of smoking gun signatures

Mütter, M.R. & Vaudrevange (2016)

❩R

4 symmetry:
  • no dimension 4 proton decay
  • dimension 5 proton decay

negligible

Michael Ratz, UC Irvine Puerto Vallarta 2017 18/ 21
slide-120
SLIDE 120 Challenges for particle physics from strings Open questions & challenges Issue 6: potential absence of smoking gun signatures

Issue 6: potential absence of smoking gun signatures

Mütter, M.R. & Vaudrevange (2016)

❩R

4 symmetry:
  • no dimension 4 proton decay
  • dimension 5 proton decay

negligible non–local GUT breaking: no dimension 6 proton decay! d

(1) red

d

(1) green

d

(1) blue

ℓ(1)

↑

ℓ(1)

↓

d

(2) red

d

(2) green

d

(2) blue

ℓ(2)

↑

ℓ(2)

↓

d

phys red ∼ d (1) red−d (2) red

d

phys green ∼ d (1) green−d (2) green

d

phys blue ∼ d (1) blue−d (2) blue

ℓphys

↑

∼ ℓ(1)

↑ +ℓ(2) ↑

ℓphys

↓

∼ ℓ(1)

↓ +ℓ(2) ↓ Michael Ratz, UC Irvine Puerto Vallarta 2017 18/ 21
slide-121
SLIDE 121 Challenges for particle physics from strings Open questions & challenges Issue 6: potential absence of smoking gun signatures

Issue 6: potential absence of smoking gun signatures

Mütter, M.R. & Vaudrevange (2016)

❩R

4 symmetry:
  • no dimension 4 proton decay
  • dimension 5 proton decay

negligible non–local GUT breaking: no dimension 6 proton decay! combined: almost no proton decay d

(1) red

d

(1) green

d

(1) blue

ℓ(1)

↑

ℓ(1)

↓

d

(2) red

d

(2) green

d

(2) blue

ℓ(2)

↑

ℓ(2)

↓

d

phys red ∼ d (1) red−d (2) red

d

phys green ∼ d (1) green−d (2) green

d

phys blue ∼ d (1) blue−d (2) blue

ℓphys

↑

∼ ℓ(1)

↑ +ℓ(2) ↑

ℓphys

↓

∼ ℓ(1)

↓ +ℓ(2) ↓ Michael Ratz, UC Irvine Puerto Vallarta 2017 18/ 21
slide-122
SLIDE 122 Challenges for particle physics from strings Open questions & challenges Issue 6: potential absence of smoking gun signatures

Issue 6: potential absence of smoking gun signatures

Mütter, M.R. & Vaudrevange (2016)

❩R

4 symmetry:
  • no dimension 4 proton decay
  • dimension 5 proton decay

negligible non–local GUT breaking: no dimension 6 proton decay! combined: almost no proton decay however: proton decay is considered to be THE smoking gun signature of unification d

(1) red

d

(1) green

d

(1) blue

ℓ(1)

↑

ℓ(1)

↓

d

(2) red

d

(2) green

d

(2) blue

ℓ(2)

↑

ℓ(2)

↓

d

phys red ∼ d (1) red−d (2) red

d

phys green ∼ d (1) green−d (2) green

d

phys blue ∼ d (1) blue−d (2) blue

ℓphys

↑

∼ ℓ(1)

↑ +ℓ(2) ↑

ℓphys

↓

∼ ℓ(1)

↓ +ℓ(2) ↓ Michael Ratz, UC Irvine Puerto Vallarta 2017 18/ 21
slide-123
SLIDE 123 Challenges for particle physics from strings Summary & outlook

Summary

☞ Despite considerable progress we do not yet have embedded the standard model into string theory

half full half empty

Michael Ratz, UC Irvine Puerto Vallarta 2017 19/ 21
slide-124
SLIDE 124 Challenges for particle physics from strings Summary & outlook

Summary

☞ Despite considerable progress we do not yet have embedded the standard model into string theory ☞ Yet string theory does make some definite predictions:

1 all symmetries, including discrete ones, need to be anomaly–free e.g. Witten (2017) Michael Ratz, UC Irvine Puerto Vallarta 2017 19/ 21
slide-125
SLIDE 125 Challenges for particle physics from strings Summary & outlook

Summary

☞ Despite considerable progress we do not yet have embedded the standard model into string theory ☞ Yet string theory does make some definite predictions:

1 all symmetries, including discrete ones, need to be anomaly–free e.g. Witten (2017) 2 no crazy representations such as 126 of SO(10) e.g. Dienes & March-Russell (1996) Michael Ratz, UC Irvine Puerto Vallarta 2017 19/ 21
slide-126
SLIDE 126 Challenges for particle physics from strings Summary & outlook

Summary

☞ Despite considerable progress we do not yet have embedded the standard model into string theory ☞ Yet string theory does make some definite predictions:

1 all symmetries, including discrete ones, need to be anomaly–free e.g. Witten (2017) 2 no crazy representations such as 126 of SO(10) e.g. Dienes & March-Russell (1996) 3 geometric interpretation of all symmetries:

a continuous symmetries: properties of compact dimensions

Michael Ratz, UC Irvine Puerto Vallarta 2017 19/ 21
slide-127
SLIDE 127 Challenges for particle physics from strings Summary & outlook

Summary

☞ Despite considerable progress we do not yet have embedded the standard model into string theory ☞ Yet string theory does make some definite predictions:

1 all symmetries, including discrete ones, need to be anomaly–free e.g. Witten (2017) 2 no crazy representations such as 126 of SO(10) e.g. Dienes & March-Russell (1996) 3 geometric interpretation of all symmetries:

a continuous symmetries: properties of compact dimensions b R symmetries: (dicrete) remnants of Lorentz symmetry of compact dimensions

Michael Ratz, UC Irvine Puerto Vallarta 2017 19/ 21
slide-128
SLIDE 128 Challenges for particle physics from strings Summary & outlook

Summary

☞ Despite considerable progress we do not yet have embedded the standard model into string theory ☞ Yet string theory does make some definite predictions:

1 all symmetries, including discrete ones, need to be anomaly–free e.g. Witten (2017) 2 no crazy representations such as 126 of SO(10) e.g. Dienes & March-Russell (1996) 3 geometric interpretation of all symmetries:

a continuous symmetries: properties of compact dimensions b R symmetries: (dicrete) remnants of Lorentz symmetry of compact dimensions c flavor symmetries: ‘crystallography’ of compact space

Michael Ratz, UC Irvine Puerto Vallarta 2017 19/ 21
slide-129
SLIDE 129 Challenges for particle physics from strings Summary & outlook

Summary

☞ Despite considerable progress we do not yet have embedded the standard model into string theory ☞ Yet string theory does make some definite predictions:

1 all symmetries, including discrete ones, need to be anomaly–free e.g. Witten (2017) 2 no crazy representations such as 126 of SO(10) e.g. Dienes & March-Russell (1996) 3 geometric interpretation of all symmetries:

a continuous symmetries: properties of compact dimensions b R symmetries: (dicrete) remnants of Lorentz symmetry of compact dimensions c flavor symmetries: ‘crystallography’ of compact space

☞ New public codes make the analysis of string models more feasible

Michael Ratz, UC Irvine Puerto Vallarta 2017 19/ 21
slide-130
SLIDE 130 Challenges for particle physics from strings Summary & outlook

Summary

☞ Despite considerable progress we do not yet have embedded the standard model into string theory ☞ Yet string theory does make some definite predictions:

1 all symmetries, including discrete ones, need to be anomaly–free e.g. Witten (2017) 2 no crazy representations such as 126 of SO(10) e.g. Dienes & March-Russell (1996) 3 geometric interpretation of all symmetries:

a continuous symmetries: properties of compact dimensions b R symmetries: (dicrete) remnants of Lorentz symmetry of compact dimensions c flavor symmetries: ‘crystallography’ of compact space

☞ New public codes make the analysis of string models more feasible ☞ Some of the constructions on the market may belong to the swampland

Michael Ratz, UC Irvine Puerto Vallarta 2017 19/ 21
slide-131
SLIDE 131 Challenges for particle physics from strings Summary & outlook

Outlook

☞ More insights by analyzing known heterotic constructions using F–theory

Michael Ratz, UC Irvine Puerto Vallarta 2017 20/ 21
slide-132
SLIDE 132 Challenges for particle physics from strings Summary & outlook

Outlook

☞ More insights by analyzing known heterotic constructions using F–theory ☞ Constructions without low–energy supersymmetry appear to deserve more attention

Michael Ratz, UC Irvine Puerto Vallarta 2017 20/ 21
slide-133
SLIDE 133 Challenges for particle physics from strings Summary & outlook

Outlook

☞ More insights by analyzing known heterotic constructions using F–theory ☞ Constructions without low–energy supersymmetry appear to deserve more attention ☞ New methods such as machine learning may lead to further progress

Michael Ratz, UC Irvine Puerto Vallarta 2017 20/ 21
slide-134
SLIDE 134

Muchas gracias! Enjoy the conference!

slide-135
SLIDE 135 Challenges for particle physics from strings Appendix References

References I

Steven Abel, Keith R. Dienes & Eirini Mavroudi. Towards a nonsupersymmetric string phenomenology. Phys. Rev., D91(12): 126014, 2015. doi: 10.1103/PhysRevD.91.126014. Lara B. Anderson, Andrei Constantin, James Gray, Andre Lukas & Eran

  • Palti. A Comprehensive Scan for Heterotic SU(5) GUT models.

JHEP, 01:047, 2014. doi: 10.1007/JHEP01(2014)047. Carlo Angelantonj & Ignatios Antoniadis. Suppressing the cosmological constant in nonsupersymmetric type I strings. Nucl. Phys., B676: 129–148, 2004. doi: 10.1016/j.nuclphysb.2003.09.047. Carlo Angelantonj, Ioannis Florakis & Mirian Tsulaia. Universality of Gauge Thresholds in Non-Supersymmetric Heterotic Vacua. Phys. Lett., B736:365–370, 2014. doi: 10.1016/j.physletb.2014.08.001. David Bailin & Alex Love. Kahler potentials for twisted sectors of Z(N)

  • rbifolds. Phys. Lett., B288:263–268, 1992. doi:

10.1016/0370-2693(92)91101-E.

Michael Ratz, UC Irvine Puerto Vallarta 2017 1/ 8
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SLIDE 136 Challenges for particle physics from strings Appendix References

References II

Michael Blaszczyk, Stefan Groot Nibbelink, Michael Ratz, Fabian Ruehle, Michele Trapletti, et al. A Z2xZ2 standard model. Phys. Lett., B683: 340–348, 2010. doi: 10.1016/j.physletb.2009.12.036. Michael Blaszczyk, Stefan Groot Nibbelink, Orestis Loukas & Saúl Ramos-Sánchez. Non-supersymmetric heterotic model building. JHEP, 10:119, 2014. doi: 10.1007/JHEP10(2014)119. Felix Brümmer, Rolf Kappl, Michael Ratz & Kai Schmidt-Hoberg. Approximate R-symmetries & the mu term. JHEP, 04:006, 2010. doi: 10.1007/JHEP04(2010)006. Wilfried Buchmüller, Koichi Hamaguchi, Oleg Lebedev, Saul Ramos-Sánchez & Michael Ratz. Seesaw neutrinos from the heterotic string. Phys. Rev. Lett., 99:021601, 2007. Wilfried Buchmüller, Markus Dierigl, Emilian Dudas & Julian Schweizer. Effective field theory for magnetic compactifications. JHEP, 04:052,

  • 2017a. doi: 10.1007/JHEP04(2017)052.
Michael Ratz, UC Irvine Puerto Vallarta 2017 2/ 8
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SLIDE 137 Challenges for particle physics from strings Appendix References

References III

Wilfried Buchmüller, Markus Dierigl, Paul-Konstantin Oehlmann & Fabian

  • Ruehle. The Toric SO(10) F-Theory Landscape. 2017b.

Keith R. Dienes. Solving the hierarchy problem without supersymmetry

  • r extra dimensions: An Alternative approach. Nucl. Phys., B611:

146–178, 2001. doi: 10.1016/S0550-3213(01)00344-3. Keith R. Dienes. Statistics on the heterotic landscape: Gauge groups & cosmological constants of four-dimensional heterotic strings. Phys. Rev., D73:106010, 2006. doi: 10.1103/PhysRevD.73.106010. Keith R. Dienes & John March-Russell. Realizing higher-level gauge symmetries in string theory: New embeddings for string guts. Nucl. Phys., B479:113–172, 1996.

  • E. Dudas & Cristina Timirgaziu. Nontachyonic Scherk-Schwarz

compactifications, cosmology & moduli stabilization. JHEP, 03:060,

  • 2004. doi: 10.1088/1126-6708/2004/03/060.
Michael Ratz, UC Irvine Puerto Vallarta 2017 3/ 8
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SLIDE 138 Challenges for particle physics from strings Appendix References

References IV

Alon E. Faraggi & Mirian Tsulaia. On the Low Energy Spectra of the Nonsupersymmetric Heterotic String Theories. Eur. Phys. J., C54: 495–500, 2008. doi: 10.1140/epjc/s10052-008-0545-2. Alon E. Faraggi, John Rizos & Hasan Sonmez. Classification of Standard-like Heterotic-String Vacua. 2017. Maximilian Fischer, Saúl Ramos-Sánchez & Patrick K. S. Vaudrevange. Heterotic non-Abelian orbifolds. JHEP, 1307:080, 2013a. doi: 10.1007/JHEP07(2013)080. Maximilian Fischer, Michael Ratz, Jesus Torrado & Patrick K.S.

  • Vaudrevange. Classification of symmetric toroidal orbifolds. JHEP,

1301:084, 2013b. doi: 10.1007/JHEP01(2013)084.

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Stefan Groot Nibbelink, Denis Klevers, Felix Plöger, Michele Trapletti, & Patrick K. S. Vaudrevange. Compact heterotic orbifolds in blow-up. JHEP, 04:060, 2008. doi: 10.1088/1126-6708/2008/04/060. Stefan Groot Nibbelink, Orestis Loukas, Fabian Ruehle & Patrick K. S.

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Nemanja Kaloper & John Terning. Landscaping the Strong CP Problem. 2017. Rolf Kappl, Hans Peter Nilles, Sául Ramos-Sánchez, Michael Ratz, Kai Schmidt-Hoberg & Patrick K.S. Vaudrevange. Large hierarchies from approximate R symmetries. Phys. Rev. Lett., 102:121602, 2009. doi: 10.1103/PhysRevLett.102.121602. Rolf Kappl, Bjoern Petersen, Stuart Raby, Michael Ratz, Roland Schieren & Patrick K.S. Vaudrevange. String-derived MSSM vacua with residual R symmetries. Nucl. Phys., B847:325–349, 2011. doi: 10.1016/j.nuclphysb.2011.01.032. Sven Krippendorf, Hans Peter Nilles, Michael Ratz & Martin Wolfgang

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References VII

Oleg Lebedev, Hans Peter Nilles, Stuart Raby, Saúl Ramos-Sánchez, Michael Ratz, Patrick K. S. Vaudrevange & Akin Wingerter. A mini-landscape of exact MSSM spectra in heterotic orbifolds. Phys. Lett., B645:88, 2007a. Oleg Lebedev, Hans-Peter Nilles, Stuart Raby, Saúl Ramos-Sánchez, Michael Ratz, Patrick K. S. Vaudrevange & Akin Wingerter. Low Energy Supersymmetry from the Heterotic Landscape. Phys. Rev. Lett., 98:181602, 2007b. doi: 10.1103/PhysRevLett.98.181602. Oleg Lebedev, Hans Peter Nilles, Stuart Raby, Saúl Ramos-Sánchez, Michael Ratz, Patrick K. S. Vaudrevange & Akin Wingerter. The heterotic road to the MSSM with R parity. Phys. Rev., D77:046013, 2007c. Andreas Mütter, Michael Ratz & Patrick K. S. Vaudrevange. Grand Unification without Proton Decay. 2016.

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SLIDE 142 Challenges for particle physics from strings Appendix References

References VIII

Hans Peter Nilles, Saúl Ramos-Sánchez, Patrick K.S. Vaudrevange & Akin Wingerter. The Orbifolder: A Tool to study the Low Energy Effective Theory of Heterotic Orbifolds. Comput.Phys.Commun., 183: 1363–1380, 2012. doi: 10.1016/j.cpc.2012.01.026. 29 pages, web page http://projects.hepforge.org/orbifolder/. Yessenia Olguin-Trejo & Saúl Ramos-Sánchez. Kahler potential of heterotic orbifolds with multiple Kahler moduli. 2017. URL http://inspirehep.net/record/1613710/files/ arXiv:1707.09966.pdf. Stuart Raby, Michael Ratz & Kai Schmidt-Hoberg. Precision gauge unification in the MSSM. Phys. Lett., B687:342–348, 2010. doi: 10.1016/j.physletb.2010.03.060. Cumrun Vafa. The String landscape & the swampland. 2005. Edward Witten. Symmetry & Emergence. 2017.

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