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Landscape Naturalness M. Dine, E. Gorbatov, S. Thomas P. Graham, S. Thomas.

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Presentation on theme: "Landscape Naturalness M. Dine, E. Gorbatov, S. Thomas P. Graham, S. Thomas."— Presentation transcript:

1 Landscape Naturalness M. Dine, E. Gorbatov, S. Thomas P. Graham, S. Thomas

2 What is String Theory ? Toy Theory of Quantum Gravity …. Theory of Nature Landscape of Solutions … How in Principle and in Practice Can Predictions be Extracted from a Fundamental Theory with a Landscape of Solutions ?

3 (Technical) Naturalness Electroweak Symmetry Breaking Stabilizing Physics < TeV  Most General Form in Conflict with …. Precision EW Higgs Mass Quark and Lepton FCNC E and M Dipole Moments Four-Fermi Contact Interactions Small Neutrino Masses Proton Stability Direct Bounds on New States Mechanisms to Avoid ….. Could Standard Model be a Good Theory >> TeV ? Vacuum Energy UV-IR / Holographic Properties of (Virtual) States. Q-Gravity    »   » 10 -120 M p 4 ?

4 Fundamental Theory with a Multiverse Landscape Naturalness : Most Common on Landscape is Most Natural (Subject to some Constraints) (Landscape of Vacua + Mechanism for Populating)

5 Fundamental Theory with a Multiverse Landscape Naturalness : Most Common on Landscape is Most Natural (Subject to some Constraints) (Landscape of Vacua + Mechanism for Populating) Multiverse Wavefunctional  (  )  = Cosmological Trajectory on the Landscape Correlations Among Observables : Necessarily Probabilistic Observables MultiverseExternal Measure Measure / Restrictions Note: No Predictions Without (Some Assumptions For). Correlations from Underlying Theory

6 Experimental Priors y j à Versus ! External Restrictions  (  ) Give up Explaining Relations Among. Known Observables Give up Practical Utility of Program Selection Effects are Not Physical Principles But Must Admit that in a Multiverse there are in Fact Selection Effects May not be clear when to Stop Note: No Predictions Without (Some Assumptions For). Correlations from Underlying Theory Here y j = { Current Data }  No Weighting by “Observers” Conditional

7 Vacuum Energy (Banks ; Linde ; Weinberg) 0 Rapid Collapse of Universe Galaxy Formation Suppressed Any Galaxy Forms Weight by Fraction of Collapsed Baryon Acceleration Terminates Galaxy Formation few

8 Vacuum Energy (Banks ; Linde ; Weinberg) 0 Rapid Collapse of Universe Galaxy Formation Suppressed Any Galaxy Forms Weight by Fraction of Collapsed Baryon Acceleration Terminates Galaxy Formation few i) Hold Everything Fixed but  (No Correlations) ii) P(  ) smooth near  ' 0 (mild) Assumptions :

9 V = 0 If Vacuum Energy Uncorrelated and Random Local Minima All the Ingredients Take Landscape Seriously …. Discretuum Vacuum Energy on the Landscape N us À 10 120 N vac > 10 10 10+?

10 Problems with Implementing Landscape Naturalness for. Other Observables Full Landscape and {  } Unknown Full  (  ) Unknown Much of Landscape may be Incalculable. (Restrict to Representative ? Samples) Measure D  Unknown Restrict to Local Minima – Unlikely Uniformly Populated Can’t Calculate Many Observables of Interest Even in a Single Vacuum. (Limited to Discrete Quantities) Possible to Make Analogous Predictions ?

11 Problems with Implementing Landscape Naturalness for. Other Observables Full Landscape and {  } Unknown Full  (  ) Unknown Much of Landscape may be Incalculable. (Restrict to Representative ? Samples) Measure D  Unknown Restrict to Local Minima – Unlikely Uniformly Populated Can’t Calculate Many Observables of Interest Even in a Single Vacuum. (Limited to Discrete Quantities) Identify Robust Quantities  Classify Distributions of Vacua Origin of Small Parameters (Associated with Large Hierarchies). on the Landscape - EW Hierarchy, Vacuum Energy, Inflation, Yukawas, ….

12 Importance of Symmetries on the Landscape 0 x Unprotected by Symmetry P(x) x

13 Importance of Symmetries on the Landscape 0 x Unprotected by Symmetry x Protected by Unbroken Symmetry P(x) x

14 Importance of Symmetries on the Landscape 0 x Unprotected by Symmetry x Protected by Unbroken Symmetry x Protected by Symmetry -- Power Law (Froggatt-Nielsen) P(x) x

15 Importance of Symmetries on the Landscape 0 x Unprotected by Symmetry x Protected by Unbroken Symmetry x Protected by Symmetry -- Power Law (Froggatt-Nielsen) x Protected by Symmetry – Exponential (Non-Perturbative) P(x) x

16 Importance of Symmetries on the Landscape 0 x Unprotected by Symmetry x Protected by Unbroken Symmetry x Protected by Symmetry -- Power Law (Froggatt-Nielsen) x Protected by Symmetry – Exponential (Non-Perturbative) (Technical) Naturalness - Important Organizing Principles on Landscape Conditional Nature of Correlations Important Note: Possible that. P(  ) >> P(  ). s P(x) dx << s P(x) dx P(x) x

17 Landscape Naturalness for Hierarchies Symmetries which Protect Hierarchy ? Mechanisms for (Hierarchical) Symmetry Compare Classes of Mechanisms Ask Correct Conditional Questions

18 The Scale of SUSY on the Landscape V ' 0 (M. Dine, E. Gorbatov, S.T.) SUSY U(1) R SUSY. Classical Classical Non-Perturbative Classical Non-Perturbative Non-Perturbative Non-Renormalization Thms Classical Non-Perturbative Classical Non-Perturbative Non-Perturbative : Assumptions :

19 SUSY U(1) R V ' 0 m Z 2 High Classical 10 -120 1-10 -32 Intermediate NPClassical10 -120 1-10 -32 LowNP 10 -60 1 10 -120 10 -60 The Branches of the Landscape

20 SUSY U(1) R V ' 0 m Z 2 High Classical 10 -120 1-10 -32 Intermediate NPClassical10 -120 1-10 -32 LowNP 10 -60 1 10 -120 10 -60 Statistics Overwhelms Tuning Tuning Overwhelms Statistics The Branches of the Landscape

21 SUSY U(1) R V ' 0 m Z 2  n High Classical 10 -120 1-10 -32 0-1/2 Intermediate NPClassical10 -120 1-10 -32 0-1/2 LowNP 10 -60 1 0 10 -120 10 -60 Relative Occurrence Each Branch The Branches of the Landscape Robust Feature of Local Supersymmetry Statistics Overwhelms Tuning Tuning Overwhelms Statistics

22 SUSY U(1) R V ' 0 m Z 2  n High Classical 10 -120 1-10 -32 0-1/2 Intermediate NPClassical10 -120 1-10 -32 0-1/2 LowNP 10 -60 1 0 10 -120 10 -60 Relative Occurrence Each Branch Sub-Branches ….. The Branches of the Landscape Robust Feature of Local Supersymmetry

23 Realization and Breaking of Symmetries (Technical) Naturalness Enforced by (Approximate) Symmetries Distributions can (Dramatically) Peak Careful About Landscape Genericity – Conditional Correlations Statistics versus Tuning SUSY Branches. Feature of Any Theory with Local Supersymmetry – Robust. Step Towards a Priori (Probabilistic) Prediction of SUSY Scale Realizations of Branches Sub-Branches Experimental Signatures ………. The Structure of the Landscape

24 Universality Classes of Landscape Correlations Correlations P(x i ;y j ) which are Insensitive to. Details of  (x i ;y j |  ) Within Some Wide Class of Vacua Predictive if 8 {  } ¾ Class Vacua 9 P(x_i ; y_j) So Narrow ) x i ' f(y j ) Universality Class of Predictions from Landscape Naturalness Opportunity to Extract Real Predictions from Landscape Naturalness. Within Classes of Vacua – Possible with Current Technology

25 Realizations of EWSB on High Scale SUSY Branch Technicolor Warped Throat Elementary Higgs ………….. Conjecture: (Statistics Overwhelm Tuning) The Higgs Sector Responsible for EWSB is a Single Elementary Scalar Higgs Doublet at or not too Far Below the Fundamental Scale The Landscape Standard Model (P. Graham, S.T.) The Entire Visible Sector is the Three Generation Standard Model at or not too Far Below the Fundamental Scale The Only Remaining Observable of EW Scale Physics is the. Higgs Mass

26 m t = 173 GeV Quasi-fixed Point m h 2 = 4 / (2 3/2 G F )

27  = 6 3 1 0.4 0.2 0.1 0.05 0 -0.05 M = 10 16 GeV Correlation Between m h and m t

28 Higgs Self Coupling M SUSY » M M SUSY < M (Cutoff in Distribution) SUSY Boundary Condition for at Matching Scale V D Potential V D (cos 2 2  = 0) = 0

29 cos 2 2  = 1 0 M = 10 16 GeV Correlation Between m h and m t – SUSY Boundary Condition

30 Higgs Self Coupling on the Landscape - SUSY Boundary Condition Assumption : Random,. Uncorrelated Step Function Gaussian h i ' 0.01 +- 0.01 (1/8)((3/5)g 1 2 +g 2 2 ) ' 0.06

31 Universality Class of P(m h :m t ) Correlation – SUSY Boundary Condition

32 LHC : > 30 fb -1  m h ' 0.2 GeV  m t ' 1 GeV h 0 ! ZZ *,   Universality Class of P(m h :m t ) Correlation – SUSY Boundary Condition

33 Corrections and Uncertainties in m h Correlation Renormalization Group Running + 100 % Finite m t pole Corrections QCD 1-Loop -10.8 % QCD 2-Loop - 3.3 % G F m t 2 1-Loop + 3.7 % G F m h 2 1-Loop - 3.5 % Finite m h pole Corrections (G F m t 2 ) 1,2 1-Loop + 2.9 % G F m h 2 1-Loop + 1.4 % Corrections :  m h / m h Uncertainties :  s (m z ) +- 1 % 2-Loop Running +- 1-2 % (estimate) Landscape Statistical +- 1.3 % Boundary Scale 10 15 – 10 18 GeV +- 0.4 % (Near  ' 0)

34 Corrections and Uncertainties in m h Correlation Renormalization Group Running + 100 % Finite m t pole Corrections QCD 1-Loop -10.8 % QCD 2-Loop - 3.3 % G F m t 2 1-Loop + 3.7 % G F m h 2 1-Loop - 3.5 % Finite m h pole Corrections (G F m t 2 ) 1,2 1-Loop + 2.9 % G F m h 2 1-Loop + 1.4 % Corrections :  m h / m h Uncertainties :  s (m z ) +- 1 % 2-Loop Running +- 1-2 % (estimate) Landscape Statistical +- 1.3 % Boundary Scale 10 15 – 10 18 GeV +- 0.4 % (Near  ' 0) Level of Irreducible Uncertainties

35 Robustness of Universality Class to UV Completion  ' 0 Delicate Boundary Condition High Scale Thresholds h t ' 0.5 Hard SUSY m SUSY < 10 -(1-2) M Slepton Flavor Violation H u, H d, L i R-Parity Violation X Additional Vector Rep States Coupled to Higgs/Sleptons Robust Universality Class of m h ' f(m t ) Correlation. Rather Insensitive to UV Physics +  (m h ;m t |  ) Slightly small Parameter m SUSY / M  W = S H u L i + 

36 SUSY Gauge Coupling Unification Landscape SM Higgs Mass Desert Desert. (No split GUT multiplets) (No significant coupling to Higgs) One Relation One Relation. Among Two Ratios Among Two Masses % Level Prediction % Level Prediction High Scale Thresholds High Scale Thresholds. Can Modify Can Modify Requires (Slightly) Requires (Slightly). Small Parameter - M U /M Small Parameter M SUSY /M Successful Prediction ?? (As yet No Other Evidence for SUSY) (Easily Disproven)

37 Gauge Coupling (Non)-Unification  1 -1 (GeV)  2 -1  3 -1 sin 2  W ' 3/7 10 17 GeV U(1) Y Normalization Brane Realizations : g 4,i -2 = V D-4 g D,i -2 Gauge Coupling Unification May Not be Landscape Natural SU(3) SU(2) Quark W-Boson Gluon

38 Living Dangerously P(x) x Selection Effect In-Hospitable Hospitable Most Likely Value Near Boundary of In-Hospitable Region

39  -1 < H 0 -1 Living Dangerously Versus Comfortably

40 Conclusions Fundamental Theory with Many Vacua . Landscape Naturalness (Conditional) Correlations Among Observables from  (  ) Symmetries Organize Structure of Landscape Supersymmetry: Non-Renormalization Thms + V ' 0 . Low, Intermediate, High Scale SUSY Branches Additional Symmetries: Sub-Branches ….. Universality Classes of Correlations  Path to Predictions Landscape Standard Model + SUSY B.C. . m h ' f(m t ) Correlation Wide Class of Vacua. Landscape Uncertainties » Irreducible Uncertainties in Calculation. Well Tested by LHC Other Universality Classes ………


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