String Compactifications and low-energy SUSY: The last attempts?

Transcription

1 String Compactifications and low-energy SUSY: The last attempts? F. Quevedo, ICTP/Cambridge Strings 2015, Bangalore, June 2015 Collaborations with (linear combinations of): L. Aparicio, M. Cicoli, B Dutta, D. Klevers, S. Krippendorf, A. Maharana, C. Mayrhofer, F. Muia, R. Valandro arxiv: , arxiv: , arxiv: , + to appear

2 Low-energy SUSY Bottom-up Recall: Hierarchy problem Gauge coupling unification (Thermal) WIMP Dark matter REWSB

3 Top-down: SUSY in 4D Strings «Calabi-Yau compactifications N=1 «Moduli stabilisation? CHSW 85 «SUSY breaking:? Fluxes (GKP), Nonperturbative effects (racetrack), Antibranes (KKLT)

4 Strings, MSSM and LHC Accept 1/100-1/1000 tuning as natural Extend the MSSM Address hierarchy problem differently within SUSY } Tuned MSSM Split SUSY (heavy sfermions, TeV fermions) Large SUSY breaking scale Non-SUSY approaches to hierarchy problem Golden opportunity for string scenarios

5 String Phenomenology: Long-term goal: String theory scenarios that satisfy all particle physics and cosmological observations and hopefully lead to measurable predictions

6 Progress in several ways Generic model independent results Explicit constructions of (classes) of models Explicit computations of EFT Extract scenarios that can lead to eventually testable predictions.

7 `Generic 4D String Predictions SUSY, small irreps, branes, fluxes, axions, no global symmetries,... Cosmological Moduli Problem (unless M moduli >30 TeV)

8 2. Moduli can cause cosmological problems: DavidModuli Marsh, University of Oxford Cosmological Problem Genericity assertions: ology Inflation After inflation 2. Moduli can cause cosmological problems: the lightest moduli start the Big Bang. sertions: 1 1 n cause cosmological problems: Modulus decay/reheating Present The typical decay rate of gravitationally coupled scalar t moduli start the Big Bang. 3 m 1. 2 al decay rate of gravitationally scalars is: 8 Mcoupled 1 Pl m 1 m & 3 10 GeV BBN requires T Banks, > O(1 MeV), Polonyi 81, Coughlan & Ross 83, Kaplan, Nelsonso 93, de Carlos, Casas, Quevedo, Roulet. 2 Coughlan et al 1983, Banks et al, de Carlos et al MPl

9 SUSY Challenges for String Scenarios Explicit N=1 Compactification Concrete SUSY breaking mechanism Moduli Stabilisation (small cc) (+ avoid CMP (plus gravitino+ dark radiation excess,etc!) Chiral visible sector Computable soft terms

10 IIB MODULI STABILISATION 4-cycle size: size: τ τ (Kahler moduli) 3-cycle 3-cycle size: U size: U (Complex (Complex structure structure moduli) moduli) + Dilaton S + String Dilaton: S

11 G2 manifolds Concrete Scenarios IIB (F-theory) KKLT LVS IIA Heterotic

12 LARGE Volume Scenario Fluxes determine superpotential W 0 (U,S) ( (GKP 2003) Perturbative corrections to K: K = 2ln V + ˆξ ) 2 Nonperturbative contributions to W: W np = X A i e a it i i Exponentially large volume for weak coupling! (SUSY broken by Fluxes, AdS) BBCQ, CQS 2005

13 LVS Conditions Need 1<h 11 <h 12 (~half Calabi-Yau s) Generic values of W flux (.1<W flux <1000) e.g. Martinez-Pedrera, Mehta, Rummel, Wesphal

14 Explicit Chiral Models

15 Concrete Compactifications From explicit compact Calabi-Yau + Chiral matter Fully supersymmetric EFT Cicoli, Klevers, Krippendorf,Mayrhofer, FQ, Valandro arxiv: All geometric moduli stabilised Volume only moderately large V~ Sequestered scenario:<t SM >=0, <F TSM >=0

16 ds Kahler Moduli Stabilisation

17 Relevant Scales String Scale Kaluza Klein Scale Gravitino mass Volume modulus mass

18 Non-generic Implications Usually moduli masses = m 3/2 And assume soft terms = m 3/2 Identify m 3/2 =1 TeV But LVS is nongeneric scenario Volume modulus mass<<m 3/2 So CMP more acute than expected! Soft terms?

19 SUSY EFT Yukawas Conlon, Cremades, FQ + Conlon, Witkowski Approximate: Local Exact: Ultralocal

20 SUSY Breaking

21 SUSY Breaking Fluxes break SUSY In EFT: F-terms of Kahler moduli (plus subdominant F S, F U ) Standard Model on a D3 or D7 brane Several scenarios

22 Compactification

23 Different SUSY Scenarios First two not yet obtained from compact CY+ chiral matter 3rd: high scale SUSY breaking (e.g. Ibanez et al.) 4 th +5 th SUSY solve hierarchy small tuning by flux dependence of GUT soft terms.

24 Sequestered Soft Terms Soft term Local Models Ultra Local 1 Ultra Local 2 i m 3/2 M 1/2 c 1/2 m 3/2 3/2 M P hln MP m 3/2 m 2 c 0 m 3/2 M 1/2 c 0 m 3/2 M 1/2 ln(m P /m 3/2 ) (c 0 ) M 2 1/2 A (c A ) M 1/2 ˆµ c µ M 1/2 B ˆµ c B m 2 0 Coefficients c: functions of fluxes

25 Cosmology: Use CMP as a guide for low energy physics

26 Constraints on the volume Validity of EFT (m 3/2 <<M kk ) : V>>10 3 CMP (m volume >30 TeV): V<10 9 Ranges of relevant scales (GeV) > M s > > m 3/2 > > M 1/2 > > T RH > 1

27 Thermal History Alternative History Scale Planck Inflation Radiation Phase (instant reheating) Scale Planck Inflation Scalar Oscillations Dominate TeV TeV GeV Thermal DM Freeze-out GeV MeV BBN Particles Decay and Reheat MeV BBN ev CMB ev CMB From S. Watson, SUSY 2013

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29 Volume Reheating* *Sequestered scenarios M.Cicoli, J.P. Conlon, FQ T. Higaki, F.Takahashi arxiv: arxiv: Volume axion a b Higgses Closed string axions T reheat m3/2 M 1/2 Pl Matter scalars C 0.6 GeV m 3/ GeV

30 Energy density: Dark Radiation Standard Model N eff =3.04 At CMB: WMAP, ACT, SPT Planck 2015: N eff = 3.13 ± 0.32 (68% CL) reduced evidence for dark ra Simplest Z=1: General: Strong constraints on matter and couplings!

31 Phenomenology

32 Nonthermal CMSSM* Assume: CMSSM parameters (M,m,A,tanβ, signµ plus T R ) REWSB with 125 GeV Higgs Constraints: T rh <T f =m/20 Colliders (LEP, LHC) CMB (Planck) Direct DM dtection (LUX, XENON100, CDMS, IceCube) Indirect DM detection (Fermi) * Warning: at this stage is purely phenomenological not stringy!

33 Collider and CMB constraints

34 Direct and Indirect DM Constraints

35 Survivors Neutralino Higgsino-like saturates Planck s density for m=300 GeV, T R =2 GeV

36 Spectrum LHC signatures: Monojets + soft leptons + ME Vector boson fusion jets + large ME

37 Large scale and split SUSY? In progress: strong Higgs mass constraints, explicit determination of splitting m~v 1/2 M = m SUSY (GeV) b = 0.1 b = tan( )

38 CONCLUSIONS Global embedding CY and Moduli Stabilisation Several SUSY breaking scenarios (tuning at UV, low T R ) Most known ingredients used: geometry, fluxes, branes, perturbative, non-perturbative effects Cosmology-Phenomenology interplay Complicated models (but recall SM is ugly) Many open questions (MSSM, large scales, etc. + formal aspects)