Directions for BSM physics from Asymptotic Safety

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1 Bad Honnef Directions for BSM physics from Asymptotic Safety phenomenology connecting theory to data Gudrun Hiller, TU Dortmund q f e DFG FOR 1873 et 1

2 Asymptotic Safety pheno for cosmology colliders a) low scale quantum gravity b) beyond the standard model (BSM), this talk 2

3 The standard model of particle physics The standard model = most economical framework that describes data LHC (Run2): pp-collisions with 6.5 TeV on 6.5 TeV; 1 TeV = 1000 m p, 18 params +ν s, strong CP 3

4 The standard model today Quantum field theory in 4D with local symmetry SU(3) C SU(2) L U(1) Y SU(3) C U(1) em L SM = 1 4 F 2 + ψi Dψ (DΦ)2 ψy ψφ + µ 2 Φ 2 λφ 4 F : carriers of strong, weak and electromagnetic force; Spin 1 ψ: matter: quarks + leptons; Spin 1/2 Φ: The standard model Higgs boson; Spin 0. Masses from spontaneous breaking of electroweak symmetry. 4

5 Physics at highest Energies Length [m] Bohr-radius nano 10 9 visible light 10 6 Energy Λ EWK Λ QCD E Deuteron E Rydberg SM/BSM? W Z 2 ev t b τ c µ s h u d e particle physics atomic,nuclear physics 5

6 The Quest for Beyond the Standard Model (BSM) phenomenon-driven: Dark matter Ω DM 22% Baryon-Asymmetry of the Universe (n n)/s Neutrino masses Flavor puzzle m up /m top 10 5, fermion mixing Flavor anomalies LHCb 2014,17: muons seem to differ more from electrons than we thought theory concepts: GUTs, SUSY, Asymptotic Safety (AS)! The standard model is an effective low energy limit of a more fundamental theory 6

7 Running couplings Running of QCD Particle Data Group dβ(α s )/dlnµ = Bα 2 s +..., B SM > 0 Is it possible that α s does not vanish in the UV and becomes AS? 7

8 8 Running couplings

9 AS BSM model building Proof of principle for gauge-yukawa theories for AS Litim, Sannino 14 in Veneziano Limes N C, N F, N F /N C = const: combined RG-running of SU(N C ) gauge coupling and yukawa coupling α y assumes finite UV-fixed point. Exact. SM-like theory. Ingredients: N F vector-like quarks coupled to N F N F scalar singlet matrix field A) Can we embed SM? Virtues? B) Can we experimentally test such models? Put bounds? C)... 9

10 The standard model and BSM sector Bond et al arxiv: yukawa interaction L BSM = ytr ψ L Sψ R + h.c field SU(3) C SU(2) L Y multiplicity Q 3 2 1/6 3 U 3 1 2/3 3 D 3 1 1/3 3 L 1 2 1/2 3 E H 1 2 1/2 1 ψ L R 3 R 2 Y N F ψ R R 3 R 2 Y N F S NF 2 params: representations R 3, R 2, hypercharge Y and number of flavors N F 10

11 Fixed points right: fully interacting, others: partial left: α 3 = 0, mid α 2 = 0 weak coupling fixed points exist for higher reps of SU(3) C SU(2) L 11

12 Matching Matching scale onto SM can be TeV-ish, or not. Crucial for phenomenology. 12

13 Collider signatures modified RG New fermions charged under SM gauge interactions. (also in large N f -models Mann et al , Pelaggi et al ) RG-running modified Iff colored, m ψ 1.5 TeV 13

14 Collider signatures EWK precision New fermions charged under SM gauge interactions. Iff weakly charged, contributions to W, Z-precision observables. W = (α 2 /10)(m 2 W /m2 ψ )BBSM 2 Ruderman et al 14,16 left: today, right: future Bond et al arxiv:

15 Collider signatures R-hadrons New, colored fermions can be pair-produced at the LHC pp > ψψ if 2m ψ < s. They are long-lived and form QCD-bound states: R-hadrons (known from SUSY models) CMS, ATLAS searches re-interpretied Bond et al arxiv:

16 Collider signatures: Yukawa-induced Yukawa-induced signatures iff R 3 1 and m S < 2m ψ, and m S < s. GG = gg, γγ, W W, ZZ, Zγ Dijet cross sections pose very strong constraints Bond et al arxiv:

17 Collider signatures: Yukawa-induced strip has m ψ m S 2m ψ 17

18 Collider signatures: Yukawa-induced Ratios of diboson cross sectons can be predicted Γ V V /Γ gg in terms of ratios fo gauge couplings and R 3, R 2 Bond et al arxiv:

19 U(1) Y asymptotic free Full SU(3) C SU(2) L U(1) Y with U(1) Y becomes asymptotically free: Bond, GH, Kowalska,Litim 17,18 19

20 Summary Finding the AS-SM is work in progress the race is on. Challenging as far from Veneziano-limit and AS cannot be guaranteed More work required to include all SM couplings and match to data. AS-BSM offers new class of models beyond the GUT-idea couplings are linked by Fixed Point manifold, not unified. Generic feature: new fermions which can be searched for Open tasks address SM deficiencies e.g. U(1) Y -Landau pole Bond et al Your model could be probed next have a nice summer! 20