Precision EW measurements at Run 2 and beyond

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1 Precision EW measurements at Run 2 and beyond 52 nd Rencontres de Moriond 2017 Session on Electroweak Interactions and Unified Theories Jens Erler (IF-UNAM) La Thuile Aosta Valley Italy March 18 25, 2017

2 Introduction With Higgs discovery the SM is complete With few marginal exceptions the SM has passed all tests The LHC did not (yet) find convincing evidence for physics beyond the SM If nothing else does, Dark Matter BSM physics and it may quite plausibly linger near the EW scale Revival of times where precision physics guided HEP? Renormalizable SM merely leading set of terms (the long range physics) in a non-renormalizable effective QFT? 2

3 Aim of this talk Recall key features of the global electroweak fit (CP even and flavour diagonal sector) Jure Zupan s talk (Wednesday) on observables which are richer in flavour Provide updated results Offer experimental and theoretical contexts Make the case for greater precision Highlight future directions 3

4 Electroweak fit: precise inputs One needs 5 input variables to fix the bosonic sector of the SM: SU(3) C SU(2) L U(1) Y gauge couplings and Higgs parameters. fine structure constant: α known to ± from Rydberg constant (leaves g e 2 as new physics constraint) Fermi constant: G F known to ± from muon lifetime Z mass: M Z 2 known to ± from Z-lineshape induces largest input uncertainty Higgs mass: M H 2 known to ± from kinematic reconstruction, but enters only in loops (except total width) strong coupling constant: α s (M Z ) extracted to ±1.4% from EW fit 4

5 Oblique physics beyond the SM STU describe corrections to gauge-boson self-energies T breaks custodial SO(4) a multiplet of heavy degenerate chiral fermions contributes ΔS = NC 3π i [t3l i t3r i ] 2 extra degenerate fermion family yields ΔS = 2 3π 0.21 S and T (U) correspond to dimension 6 (8) operators 5 5

6 At the of the electroweak fit I sin 2 θw: sin 2 θw = ± (Tevatron average Liang Han) calculate & compare with Z-pole measurements (LEP, SLC, Tevatron, LHC) provides crucial constraint on oblique parameters restricts the Z-Zʹ mixing angle to sub-% level compare Z-pole with off-pole measurements to address possible new contact interactions 6

7 0.245 Running weak mixing angle results and prospects measurements proposed Q W (p) Q W (e) NuTeV sin 2 θ W (µ) Q W (APV) edis MOLLER Tevatron LEP 1 SLC LHC Mainz-P2 SoLID LHC 300/fb Mainz-C Qweak (final) LHC 3/ab µ [GeV] 7

8 sin 2 θ eff (e) A FB (b) A LR (had) M H [GeV] JE

9 At the of the electroweak fit II M W = ± GeV (LEP combination) M W = ± GeV (Tevatron combination Liang Han) M W = ± GeV 7 TeV and 4.6 fb 1 ) M W = ± GeV (world average assuming 7 MeV common PDF error) 1 M W 2 M Z 2 = ± oblique constraint independent of sin 2 θ W M W = ± GeV (global fit) M W is easily affected by new physics in general and Higgs sector modification in particular, but needs m t. 9

10 Top quark mass mt = ± 0.34stat. ± 0.61syst. GeV ATLAS arxiv: mt = ± 0.35stat. ± 0.54syst. GeV Tevatron arxiv: mt = ± 0.13stat. ± 0.46syst. GeV CMS-PAS-TOP /2016 mt = ± 0.28uncorr. ± 0.29corr. ± 0.50QCD GeV = ± GeV (combination used for this talk) top mass still matters: change from previous mt = ± 0.81 GeV reduces MH by 3 GeV. 10

80.40 80.39 direct (1σ) indirect (1σ) all data (90%) M W [GeV] 80.38 80.37 80.36 80.

11 direct (1σ) indirect (1σ) all data (90%) M W [GeV] Freitas, JE (PDG 2016) m t [GeV] Heinemeyer, Hollik, Weiglein, Zeune

12 MH event kinematics ATLAS, CMS 2015 Higgs BRs Erler, Freitas 2015 (PDG 2016) updated electroweak fit ± 0.24 GeV ± 1.9 GeV GeV 12 12

13 Snowmass fb fb fb fb -1 now Tev. Run IIA Run IIB Run IIB LHC LC GigaZ δ sin 2 θ eff ( 10 5 ) (6) 1.3 δm W [MeV] δm t [GeV] δm H [MeV] O(2000) hep-ph/ fb -1 13

14 LHC updated electroweak fit MW only LHC@150 fb 1 MW = (8) MeV GeV GeV GeV LHC@150 fb 1 Δsin 2 θw = (20) GeV current data + LHC@150 fb 1 current + HL-LHC [8 5 & 20 14] GeV 89 ± 10 GeV neglects theory error (prediction) and assumes no improvements in parameters [αs, α(mz), ] except mt 14 14

15 Γ Z, σ had, R l, R q (1σ) Z pole asymmetries (1σ) M W (1σ) direct m t (1σ) direct M H precision data (90%) M H [GeV] m t [GeV] Freitas, JE (PDG 2016) 15

16 Charm (and bottom) quarks α(m Z ) & sin 2 θ W (0): PQCD for heavy quark contribution if masses known. g μ 2: 4.2 σ SM deviation includes τ spectral functions corrected for γ-ρ mixing Jegerlehner, Szafron 2011 c quark contribute similar to γ γ; ± 70 MeV uncertainty in m c induces an error of ± comparable to projected errors for FNAL & J-PARC experiments. 16 Yukawa coupling mass relation: Δm b = ± 9 MeV & Δm c = ± 8 MeV to match future precision in HiggsBRs Sum rule: m c = 1272 ± 8 ± 4 (α s ) MeV Masjuan, Spiesberger, JE 2016 (expect about twice the error for m b )

17 Implications of T (ρ0) parameter T all (90% CL) Γ Ζ, σ had, R l, R q asymmetries M W, Γ W e & ν scattering APV ρ0 would constrain VEVs of higher dimensional Higgs representations to 1 GeV S Erler Freitas PDG 2016 Moriond 2017 update S 0.06 ± 0.08 T 0.09 ± 0.06 Sensitivity to degenerate scalar EW doublets up to 2 TeV (using results based on EFT approach) Henning, Lu, Murayama 2014 Non-degenerate multiplets of heavy fermions or scalars Δχ

18 Non-degenerate multiplets of heavy fermions or scalars Δρ 0 = G F Σ i C i / (8 2 π 2 ) Δm i 2 [ Δm i 2 (m1 m 2 ) 2 ] despite appearance there is decoupling (see-saw type suppression of Δm i 2 ) Moriond 2017 update: ρ 0 = ± [1.6 σ (PDG 2016) 1.9 σ] Σ i C i / 3 Δm i 2 (46 GeV) LHC@150 fb 1 : assuming no SM deviation: ρ 0 = 1 ± Σ i C i / 3 Δm i 2 (27 GeV) 2 assuming no change in central value: ρ 0 = ± Σ i C i / 3 Δm i 2 = ( GeV) 2 HL-LHC assuming no deviation: ρ 0 = 1 ± Σ i C i / 3 Δm i 2 (25 GeV) 2 18

19 [2 g eu - g ed ] AV APV Qweak edis all data SM Compositeness [g eu + 2 g ed ] AV scales from low energies [2 g eu - g ed ] AV [2 g eu - g ed ] AV Qweak + APV SLAC-E122 JLab-Hall A all data SM SLAC-E122 JLab-Hall A SoLID PVES (p) PVES (C) APV (Cs) APV (Ra) APV (isotope ratios) [2 g eu - g ed ] VA TeV [g eu + 2 g ed ] AV TeV [2 g eu - g ed ] VA TeV TeV TeV 19 19

20 If there is time

21 Weak probes of the strong coupling Z width: in SM Γ Z provides clean α s constraint N ν = ± BSM: helps to separate S from T Z decays: Γ(Z hadrons) Γ(Z leptons) Z height: for hadrons least correlated τ lifetime: α s at the verge of a perturbative breakdown combined with Z-pole values gives perfect quantitative QCD test W width: currently lacks precision, but 1 st + 2 nd row CKM unitarity test 21

22 Triple gauge couplings ) -2 (TeV 2 c B /Λ CMS Preliminary 19 fb (8 TeV) Expected 68% C.L. Observed 68% C.L. Expected 95% C.L. Observed 95% C.L c W /Λ (TeV -2 ) Λnew = O(1 TeV) TGC protected by gauge invariance but deviation could be mimicked by dimension 6 operators 22

23 Conclusions SM in remarkable health: making us theorists sick SM over-constrained: derived quantities like M W, sin 2 θ W, g μ 2 and weak charges computed and measured indirect M H : 1.7 σ below direct (need precision and consistency in m t ) ρ-parameter: 1.9 σ high in SM + ρ fit (S = U = 0) M may move these to 3 σ more tantalising than 4 σ in g μ 2? better precision in M W a must with or without LHC discovery! Contact interactions: compare sin 2 θ W at low Q 2 with Z-pole and test Λ new up to 50 TeV (in strong coupling case) 23

24 BACKUP

25 αs Z decays Freitas, JE (PDG 2016) ± τ decays Freitas, JE (PDG 2016) DIS Bethke, Dissertori, Salam (PDG 2016) ± jet-event shapes in e + e Bethke, Dissertori, Salam (PDG 2016) ± lattice FLAG Working Group ± tt cross section CMS world Bethke, Dissertori, Salam (PDG 2016) ±

26 1.30 m` chm` total error resonances PQCD truncation method (OPE truncation, ) gluon condensate OHà s 0 L OHà s 1 L OHà s 2 L OHà s 3 L 26 αs JE, Masjuan, Spiesberger 2016

27 STU T (90% CL) FCC-ee Z+W+H+t (90% CL) current FCC-ee S ± ± T ± ± U ± ± S ± ± S T ± ± T ± ±

28 Non-oblique parameters long-standing deviation in A FB (b) from LEP 1 currently: ρ b = ± κ b = ± (2.7 σ) difficult to explain without affecting / tuning R b FCC-ee: ρ b ± and κ b ± or better when including A FB (b) in addition to A LR FB (b) These results are virtually independent of STU (fixed or floating) 28

Lab experiment precision Δ sin 2 θ W(0) Λnew APV 133 Cs 0.58 % 0.

0030 17.0 TeV PVDIS 4.5% 0.0051 7.6 TeV Qweak final 4.5% 0.0008 33 TeV SoLID 0.

00032 52 TeV PVES 12 C 0.3 % 0.0007 49 TeV APV 225 Ra 0.5% 0.

29 Lab experiment precision Δ sin 2 θ W(0) Λnew APV 133 Cs 0.58 % (expected) 32.3 TeV E158 14% TeV Qweak I 19% TeV PVDIS 4.5% TeV Qweak final 4.5% TeV SoLID 0.6 % TeV MOLLER 2.3 % TeV P2 1.7% TeV PVES 12 C 0.3 % TeV APV 225 Ra 0.5% TeV APV 213 Ra/ 225 Ra 0.1% TeV Belle II 0.14% 33 TeV CEPC / FCC??? 29

30 FCC-ee M Z Γ Z ± 2.1 MeV < 100 kev ± 2.3 MeV < 100 kev R μ ± < R b ± < m t σ had A LR ± 810 MeV (incl. QCD) ± 15 MeV ± 37 pb ± 4 pb (assumes 0.01% luminosity error) ± ± (needs 3-loop EW to be useful, 4-loop to match exp.) A LR FB (b) ± ± (using similar b-tagging improvements as for R b ) M W ± 33 MeV (LEP); ± 16 MeV (Tevatron) ± 0.6 MeV Γ W ± 42 MeV 1st + 2nd row CKM unitarity test 30

The electroweak fit at NNLO and prospects for LHC and ILC. Klaus Mönig

The electroweak fit at NNLO and prospects for LHC and ILC Klaus Mönig The idea of electroweak fits Electroweak interactions are the puzzling part of the Standard Model: parity (and CP) violation non-trivial