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Fingerprinting of the Higgs boson couplings as a probe of new physics models

Fingerprinting of the Higgs boson couplings as a probe of new physics models. Yagyu , Kei ( 柳生 慶 ) National Central U. Collaboration with Shinya Kanemura and Mariko Kikuchi (U. of Toyama) . Physics Letters B731, 27-35 (2014), arXiv:1401.0515 [ hep-ph ]. Academia Sinica , Mar. 7, 2014.

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Fingerprinting of the Higgs boson couplings as a probe of new physics models

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  1. Fingerprinting of the Higgs boson couplings as a probe of new physics models Yagyu, Kei (柳生 慶) National Central U. Collaboration with Shinya Kanemura and Mariko Kikuchi (U. of Toyama) Physics Letters B731, 27-35 (2014), arXiv:1401.0515 [hep-ph] Academia Sinica, Mar. 7, 2014

  2. Cavity Radiation • In the end of 19th century, people thought that physics has already been completed by Newton’s dynamics and Maxwell’s electromagnetism. • However, there were a few phenomena which couldn’t be explained by classical physics such as the spectrum of cavity radiation. Rayleigh-Jeans Low Exp. Wien’s Low (1896) Wien’s Low Rayleigh-Jeans Low (1900)

  3. Cavity Radiation • In the end of 19th century, people thought that physics has already been completed by Newton’s dynamics and Maxwell’s electromagnetism. • However, there were a few phenomena which couldn’t be explained by classical physics such as the spectrum of cavity radiation. Rayleigh-Jeans Low Exp. ~ Planck’s Low Planck’s Low (1905) Wien’s Low

  4. Paradigm Shift Early 20th century Classical Theory Quantum Theory Cavity Radiation - Nuclear Physics - Particle Physics, … -Newton Dynamics -Maxwell Electromagnetism Planck’s Low Einstein’s Light Quantum Hypothesis Cavity Radiation gave a “Bridge” connecting Classical Theory and Quantum Theory.

  5. Today We have the Standard Model. Higgs mechanism Higgs Sector Yukawa interaction Gauge interaction Gauge Sector G, W, Z, γ Matter Sector Quarks & Leptons

  6. Today We have the Standard Model. Higgs mechanism Higgs Sector Yukawa interaction Gauge interaction Gauge Sector G, W, Z, γ Matter Sector Quarks & Leptons Well tested before the LHC

  7. Today We have the Standard Model. Higgs mechanism Higgs Sector Yukawa interaction Gauge interaction Gauge Sector G, W, Z, γ Matter Sector Quarks & Leptons

  8. Today We have the Standard Model. Higgs mechanism Higgs Sector Yukawa interaction Gauge interaction Gauge Sector G, W, Z, γ Matter Sector Quarks & Leptons The LHC has found a Higgs boson with 126 GeV

  9. Today We have the Standard Model. Higgs mechanism Higgs Sector Yukawa interaction Gauge interaction Gauge Sector G, W, Z, γ Matter Sector Quarks & Leptons However, still there are unclear things in the Higgs sector.

  10. Next Paradigm Shift Today New Physics EWSB Standard Model Higgs Sector Higgs Physics could give a next “Bridge” connecting the Standard Model and New Physics!

  11. Three Questions What is the true structure of the Higgs sector? -Minimal or Non-minimal? What is the dynamics behind the Higgs sector? - Weak coupling or Strong coupling How is the Higgs sector related to the phenomena beyond the SM? - Neutrino oscillation, Dark matter, and Baryon asymmetry.

  12. Three Questions What is the true structure of the Higgs sector? -Minimal or Non-minimal? What is the dynamics behind the Higgs sector? - Weak coupling or Strong coupling How is the Higgs sector related to the phenomena beyond the SM? - Neutrino oscillation, Dark matter, and Baryon asymmetry.

  13. Minimal (1 doublet) Explained EW data, Flavor, … 126 GeV Higgs

  14. Non-MinimalHiggs sectors Singlets Doublets Triplets… Minimal (1 doublet) Extra Explained EW data, Flavor, … 126 GeV Higgs

  15. Neutrino mass, Dark matter and Baryon asymmetry Introduce Non-MinimalHiggs sectors Singlets Doublets Triplets… Minimal (1 doublet) Extra Explained EW data, Flavor, … New Physics Models 126 GeV Higgs

  16. New Physics Models Neutrino mass, Dark matter and Baryon asymmetry Determine Non-MinimalHiggs sectors Singlets Doublets Triplets… Minimal (1 doublet) Extra Determine EW data, Flavor, … 126 GeV Higgs Higgs prop.

  17. Neutrino mass, Dark matter and Baryon asymmetry Determine Non-MinimalHiggs sectors Singlets Doublets Triplets… Bottom up Approach! Minimal (1 doublet) Extra Determine EW data, Flavor, … New Physics Models 126 GeV Higgs Higgs prop.

  18. Bottom up Approach 2. Indirect search 1. Direct search Measuring effects on the 126 GeV Higgs boson Energy Discovery Energy H++, H+, H, A, ... h h 126 GeV H++, H+, H, A, … 126 GeV Studying both ways is important to determine the structure of the Higgs sector.

  19. Bottom up Approach 2. Indirect search 1. Direct search Measuring effects on the 126 GeV Higgs boson Energy Discovery Energy H++, H+, H, A, ... h h 126 GeV H++, H+, H, A, … 126 GeV Studying both ways is important to determine the structure of the Higgs sector.

  20. Indirect Search Indirect search = Precision test of Higgs couplings Experiments Theory hVV Minimal Singlet Models 2HDMs Triplet Models etc… hbb hττ Compare hcc hγγ hhh Make a “Fingerprint” from precise measurements. • Patterns of deviation in various Higgs couplings strongly depend on the structure of the Higgs sector.

  21. Higgs coupling measurements Scaling factors κV = ghVV (exp)/ghVV (SM), κF= ghFF(exp)/ghFF(SM) ATLAS-CONF-2013-034 CMS-PAS-HIG-13-005 κF κV

  22. Higgs coupling measurements 1.4 Scaling factors κV = ghVV (exp)/ghVV (SM), κF= ghFF(exp)/ghFF(SM) 1.2 ATLAS-CONF-2013-034 CMS-PAS-HIG-13-005 1 0.8 κF 0.6 The uncertainties for κF and κV are about ±40% and ±20%, respectively. κV

  23. Higgs coupling measurements ILC, TDR ILC, Higgs White Paper, arXiv: 1310.0763 (300/fb) The hZZ coupling can be measured by 1 % accuracy at the ILC(250) !

  24. Higgs coupling measurements ILC, TDR ILC, Higgs White Paper, arXiv: 1310.0763 (300/fb) The hVV and hffcouplings can be measured by 1 % accuracy at the ILC(500) !!

  25. Higgs coupling measurements ILC, TDR ILC, Higgs White Paper, arXiv: 1310.0763 (300/fb) The hVV and hffcouplings can be measured by 1 % accuracy at the ILC(500) !!

  26. Contents • Introduction • - Bottom up approach (Indirect search) • Deviations in the Higgs boson couplings in various Higgs sectors • - The hVV and hff couplings at the tree level • Higgs boson couplings in the 2HDMs • - Tree level • - One-loop level • Summery

  27. Basic Constraints There are two guidelines to restrict Higgs sectors. 1. Electroweak rho parameter +0.0003 ρexp =1.0004 -0.0004 Models with ρtree = 1 seems to be a natural choice. Satisfy the relation Alignment of (exotic) VEVs Ex. Model with doublet (Y=1/2) + triplet (Y=1) + triplet (Y=0) (Georgi-Machacek model) if

  28. Basic Constraints There are two guidelines to restrict Higgs sectors. 2. Flavor Changing Neutral Current(FCNC) Tree level FCNC process should be absent. In general, multi-doublet extensions cause FCNC at the tree level B0 B0 Φ0

  29. Basic Constraints There are two guidelines to restrict Higgs sectors. 2. Flavor Changing Neutral Current(FCNC) Tree level FCNC process should be absent. In general, multi-doublet extensions cause FCNC at the tree level B0 B0 Only one Higgs doublet couples to each fermion. Φ0

  30. Simple Extended Higgs Sectors We consider the following simple Higgs sectors; (with ρtree = 1 and no tree level FCNC) 1. Φ + S (Singlet) 2. Φ + D (Doublet) 3. Φ + Δ (Triplets or larger) [GM model, Septet model] Hisano, Tsumura, PRD87 (2013) Kanemura, Kikuchi, KY, PRD88 (2013)

  31. Two mixing angles • Mixing between CP-even states • VEVs T: isospin, Y:hypercharge where

  32. Deviations in hff and hVV • Yukawa f α φ Φ β V <φ> Yf = mf /<Φ> f <Φ> V φ Φ V V • Gauge β <φ> α

  33. Higgs Singlet Model (φ=S) • Yukawa f ★ The singlet VEV does not contribute to the EWSB. → β=∞ (<Φ>=246 GeV) α S Φ <S> Yf = mf /<Φ> f <Φ> V ★ The hff and hVV couplings are universally suppressed. Φ V • Gauge <S> α S

  34. Two Higgs Doublet Model (φ=D) • Yukawa f ★There are 2 patterns in κf for each fermion f. α β D (Φ) Φ (D) <D (Φ)> Yf = mf /<Φ (D)> f V ★ξ = 1 <Φ> V D Φ V V • Gauge β <D> α

  35. Model with a triplet (or higher) (φ=Δ) • Yukawa ★The hff couplings are universally suppressed. f α β Δ Φ ★ξ factor can be larger than unity. → κV > 1 V <Δ> Yf = mf /<Φ> f <Φ> V Δ Ex. GM model: ξ = 2*sqrt(6)/3 Septet model : ξ = 4 Φ V V • Gauge β <Δ> α

  36. SM

  37. κF’ SM

  38. κF’ κF = κF’ SM

  39. κF’ κF = κF’ SM

  40. Gauge vs Yukawa Singlet Model 2HDM (Type-I) Georgi-Machacek Model [ξ = 2*Sqrt(6)/3]

  41. Gauge vs Yukawa -π/4 < α < +π/4 0.1 < tanβ < 100 Singlet Model 2HDM (Type-I) Georgi-Machacek Model [ξ = 2*Sqrt(6)/3]

  42. Contents • Introduction • - Bottom up approach (Indirect search) • Deviations in the Higgs boson couplings in various Higgs sectors • - The hVV and hff couplings at the tree level • Higgs boson couplings in the 2HDMs • - Tree level • - One-loop level • Summery

  43. 2HDMs In general, Yukawa Lagrangian is given by To avoid the tree level FCNC, one of the Yukawa couplings should be forbidden. Z2 symmetry (softly-broken) Glashow, Weinberg, PRD15 (1977) Z2 symmetry (unbroken) Barbieri, Hall, Rychkov, PRD74 (2006) S3 symmetry Kajiyama, Okada, KY, arXiv:1309.6234 [hep-ph] U(1) symmetry Ko, Omura, Yu, JHEP1201 (2012) …

  44. 2HDMs with the softly-broken Z2sym. In general, Yukawa Lagrangian is given by To avoid the tree level FCNC, one of the Yukawa couplings should be forbidden. Z2 symmetry (softly-broken) Glashow, Weinberg, PRD15 (1977) Z2 symmetry (unbroken) Barbieri, Hall, Rychkov, PRD74 (2006) S3 symmetry Kajiyama, Okada, KY, arXiv:1309.6234 [hep-ph] U(1) symmetry Ko, Omura, Yu, JHEP1201 (2012) … There are four independent types of Yukawa interactions.

  45. Four Yukawa Interactions Φ２ Φ１ Φ２ • u u e e d d Φ２ Φ２ Φ１ u e u e d Φ１ d Under the Z2 symmetry, two doublets are transformed as Φ1→ +Φ1 and Φ2→ -Φ2. Type-I • Type-II (MSSM) • Barger, Hewett, Phillips (1990), Grossman (1994) • Aoki, Kanemura, Tsumura, KY (2008) Type-X (Leptophilic) Type-Y (Flipped)

  46. Mass Eigenstates We define the Higgs basis by introducing β tanβ = <Φ2>/<Φ1> Charged Higgs NG bosons CP-even Higgs CP-odd Higgs SM-like Higgs boson w/126 GeV

  47. Yukawa/Gauge Interaction V f h h f V = (SM) × sin(β-α) = (SM) × [sin(β-α)+ξfcos(β-α)]

  48. Higgs Potential • The Higgs potential under the softly-broken Z2 sym. and CP-invariance • We have 8 parameters in the potential. They can be interpreted by v (=246 GeV), mh (=126 GeV), mH, mA, mH+, sin(β-α), tanβ, and M2 • Mass formulae with sin(β-α) ~1 mh2 ~ λv2, mΦ2 ~ M2 + λv2 Φ = H±, A, H

  49. SM-like/Decoupling Limit • SM-like limit: taking sin(β-α) → 1 All the Higgs boson couplings become the same value as in the SM Higgs couplings at the tree level. • Decoupling limit: taking M2 (=mΦ2) → ∞ [mΦ2 ~ M2 + λv2] Decoupling limit can be taken only when the SM-like limit is taken.

  50. Decoupling/SM-like Limit 10% dev. cos(β-α) > 0 Excluded by unitarity cos(β-α) < 0 1% dev. δ = 0.1% dev. (mH= mA= mH+= M =)

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