Lepton Physics One of the four pillars: Tera-Z, Oku-W, Mega-H, Mega-t John Ellis M = ± 0.8 GeV, ε =

Projected e + e - Colliders: Luminosity vs Energy TLEP physics study group: arXiv:

Global Analysis of Higgs-like Models Rescale couplings: to bosons by a, to fermions by c Standard Model: a = c = 1 JE & Tevong You, arXiv: b bbarτ γ W Z Global No evidence for deviation from SM

It Walks and Quacks like a Higgs Do couplings scale ~ mass? With scale = v? Red line = SM, dashed line = best fit JE & Tevong You, arXiv: Global fit

What Next: A Higgs Factory? To study the ‘Higgs’ in detail: The LHC –Consider LHC upgrades in this perspective A linear collider? –ILC up to 500 GeV –CLIC up to 3 TeV (Larger cross section at higher energies) A circular e + e - collider? An ep collider? A γγ collider? A muon collider? Wait for results from 13/14 TeV

Possible High-Luminosity LHC Measurements

Possible Future Higgs Measurements Janot

H Coupling Measurements M = ± 0.8 GeV, ε = JE & Tevong You

Indirect Sensitivity to 3h Coupling Loop corrections to σ(H+Z): 3h correction δ h energy-dependent δ Z energy-independent: can distinguish McCullough

Predictions of current best fits in simple SUSY models Current uncertainties in SM calculations [LHC Higgs WG] Comparisons with –LHC –HL-LHC –ILC –TLEP (= FCC-ee) (Able to distinguish from SM) Impact of Higgs Measurements K. De Vries (MasterCode)

Possible FCC-ee Precision Measurements

TLEP Measurements of m t & M W

Theoretical Constraints on Higgs Mass Large M h → large self-coupling → blow up at low-energy scale Λ due to renormalization Small: renormalization due to t quark drives quartic coupling < 0 at some scale Λ → vacuum unstable Vacuum could be stabilized by Supersymmetry Degrassi, Di Vita, Elias-Miro, Giudice, Isodori & Strumia, arXiv: – GeV

Vacuum Instability in the Standard Model Very sensitive to m t as well as M H Instability scale: Calculate with accuracy ± 0.1 Buttazzo, Degrassi, Giardino, Giudice, Sala, Salvio & Strumia, arXiv: FCC-ee accuracy

Sensitivity to Higher-Dimensional Operators Possible new physics corrections to SM: LEP constraints FCC-ee constraints See Λ ~ 100 TeV? JE, Sanz & You

What else is there? Supersymmetry Successful prediction for Higgs mass –Should be < 130 GeV in simple models Successful predictions for couplings –Should be within few % of SM values Naturalness, GUTs, string, … (???)

Data Electroweak precision observables Flavour physics observables g μ - 2 Higgs mass Dark matter LHC MasterCode: O.Buchmueller, JE et al.

Search with ~ 8 TeV

p-value of simple models ~ 5% (also SM) /fb Scan of CMSSM Buchmueller, JE et al: arXiv:

Confronted with likelihood analysis of CMSSM LHC Reach for Supersymmetry K. De Vries (MasterCode)

Confronted with likelihood analysis of CMSSM Direct Reach for Supersymmetry Stau mass contours 500 GeV (ILC1000) 1500 GeV (CLIC) TLEP, ILC500 have no impact K. De Vries (MasterCode)

Γ Z constraint on (m0, m1/2) plane in CMSSM: All points within one current σ of low-mass best-fit value Impact of LEP Precision on Susy K. De Vries (MasterCode)

Γ Z constraint on (m 0, m 1/2 ) plane in CMSSM: Points within one, two, three TLEP σ of low-mass best-fit value Impact of FCC-ee Precision on Susy K. De Vries (MasterCode) ΓZΓZ

M W constraint on (m 0, m 1/2 ) plane in CMSSM: All points within one current σ of low-mass best-fit value Impact of FCC-ee Precision on Susy K. De Vries (MasterCode) MWMW

Estimate of (m 0, m 1/2 ) in CMSSM on basis of precision measurements with low-mass best-fit central values Impact of FCC-ee Precision on Susy K. De Vries (MasterCode)

One-dimensional likelihood functions in CMSSM if precision measurements with low-mass best-fit central values: compare masses with LHC measurements, Test SUSY at the loop level Impact of FCC-ee Precision on Susy K. De Vries (MasterCode)

Assume no HL-LHC: current precision measurements with high-mass best-fit values Impact of HL-LHC on Susy K. De Vries (MasterCode)

One-dimensional likelihood functions in CMSSM if precision measurements with high-mass best-fit central values: Predict masses for FCC-pp measurements Impact of FCC-ee Precision on Susy K. De Vries (MasterCode)

The Twin Frontiers of FCC-ee Physics Precision Measurements Springboard for sensitivity to new physics Theoretical issues: –Higher-order QCD –Higher-order EW –Mixed QCD + EW Experimental issues –Gigi Rolandi Rare Decays Direct searches for new physics Many opportunities Z: b, c, τ: W: 10 8 H: 10 6 t: 10 6

cf, LEP and LHC “Those who don't know history are doomed to repeat it…” –Edmund Burke “… and maybe also those who do.” LEP: Precision Z studies, W+W-, search for Higgs, anything else LHC: search for Higgs, anything else FCC-ee, -pp together: 50 years of physics ✔ ✖ ✔ ?

O. Buchmueller, R. Cavanaugh, M. Citron, A. De Roeck, M.J. Dolan, J.E., H. Flacher, S. Heinemeyer, G. Isidori, J. Marrouche, D. Martinez Santos, S. Nakach, K.A. Olive, S. Rogerson, F.J. Ronga, K.J. de Vries, G. Weiglein

July 4 th 2012 The discovery of a new particle

Possible Future Higgs Measurements Need to reduce theoretical uncertainties to match Essential for new physics interpretations

Impact of TLEP Precision on Susy M W constraint on stop masssin 2 θ W constraint on stop mass V. Sanz TLEP physics study group: arXiv:

R l constraint on (m0, m1/2) plane in CMSSM Points within one, two, three TLEP σ of low-mass best-fit value Impact of FCC-ee Precision on Susy K. De Vries (MasterCode) RlRl