Nonstandard Yukawa Couplings Joachim Brod Workshop The CP nature of - PowerPoint PPT Presentation

Nonstandard Yukawa Couplings Joachim Brod Workshop “The CP nature of the Higgs boson” Amherst Center for Fundamental Interactions – May 2, 2015 Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 1 / 42

Motivation – NP at LHC We have found New Physics (NP) at the LHC! ⇒ The Higgs Yet, we still need to find NP beyond the Standard Model (BSM) The discovery of the/a Higgs boson opens a new window to NP BSM CP violation In the quark sector consistent with SM Already probe scales of up to O (10 4 ) TeV CP violation in the Higgs sector? Interesting for electroweak baryogenesis Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 2 / 42

Motivation – SM Higgs σ (stat.) Total uncertainty ATLAS Preliminary ( sys inc. ) σ theory 1 on m = 125.36 GeV ± σ µ H σ (theory) Higgs couplings completely determined in the SM H → γ γ + 0.23 0.23 - + 0.16 = 1.17 + 0.28 0.11 µ - 0.12 0.26 + - - 0.08 H → ZZ* + 0.35 - 0.31 0.19 + µ = 1.46 + 0.40 - 0.13 SM Yukawas are + 0.18 0.34 - - 0.11 0.16 H → WW* + - 0.16 0.17 + µ = 1.18 + 0.24 - 0.14 + 0.13 - 0.21 - 0.09 0.31 + H → b b - 0.30 + 0.24 flavor-diagonal µ = 0.63 + 0.39 - 0.23 + 0.09 - 0.37 - 0.07 + 0.30 H → τ τ - 0.29 + 0.29 0.42 µ = 1.44 + - 0.23 + 0.16 - 0.37 real (CP-conserving) - 0.10 + 3.6 H → µ µ - 3.6 + 0.5 3.7 µ = -0.7 + - 0.7 + 0.4 - 3.7 - 0.4 H Z + 4.3 → γ - 4.2 + 1.7 4.6 Experimentally, we know nearly nothing about the µ = 2.7 + - 1.3 + 1.1 - 4.5 0.3 - Combined + 0.10 - 0.10 light-fermion Yukawas + 0.11 0.15 µ = 1.18 + - 0.10 + 0.08 - 0.14 0.07 - − 1 0 1 2 3 s = 7 TeV, 4.5-4.7 fb -1 Signal strength ( µ ) s = 8 TeV, 20.3 fb -1 Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 3 / 42

How can we change the Higgs couplings? Operator Mass term Higgs-fermion coupling y t ( ¯ m t = y t v y t Q L t R H c ) + h.c. √ √ 2 2 √ √ 2) 3 2) 2 H † H Λ 2 ( ¯ δ m t ∝ ( v / δ y t ∝ 3 ( v / Q L t R H c ) + h.c. Λ 2 Λ 2 Mass and Yukawa term become independent Relative complexe phase → CP violation More generally, we write: Y = − y f κ f ) ¯ L ′ √ ( κ f + i ˜ f L f R h + h.c. 2 Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 4 / 42

Motivation – baryogenesis [Huber, Pospelov, Ritz, hep-ph/0610003] A minimal setup for baryogenesis: L = 1 Λ 2 ( H † H ) 3 + Z t Λ 2 ( H † H ) ¯ Q 3 H c t R Λ ∼ 500 − 800 GeV gives correct η b In principle there are more operators Simple UV completion: Second heavy Higgs doublet H h Λ ∼ M H h Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 5 / 42

Motivation – EDM constraints on baryogenesis [Huber, Pospelov, Ritz, hep-ph/0610003] Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 6 / 42

Outline CPV Yukawa couplings Light-fermion Yukawas Flavor changing Higgs couplings Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 7 / 42

CP-violating Yukawa couplings Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 8 / 42

From h → γγ . . . In the SM, Yukawa coupling to fermion f is L Y = − y f ¯ √ γ f f h 2 We will look at modification h � � Y = − y f t κ f ¯ κ f ¯ L ′ √ f f + i ˜ f γ 5 f h 2 γ New contributions will modify Higgs production cross section and decay rates Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 9 / 42

. . . to electric dipole moments Attaching a light fermion line leads to EDM Indirect constraint on CP -violating Higgs γ coupling f SM “background” enters at three- and h four-loop level t Complementary to collider measurements f γ Constraints depend on additional f assumptions Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 10 / 42

Electric Dipole Moments (EDMs) – Generalities Energy Higher-dimensional T eV Higgs e ective operators Modi ed Higgs couplings GeV QCD neutron EDM nuclear EDMs of para- EDMs of atomic magnetic atoms diamagnetic and molecules atoms [Adapted from Pospelov et al., 2005] Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 11 / 42

CPV in htt couplings Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 12 / 42

Constraints from gg → h gg → h generated at one loop Have effective potential α s α s h h µν G µν, a − ˜ µν � G µν, a v G a v G a V eff = − c g c g 12 π 8 π g c g , ˜ c g given in terms of loop functions h b, t κ g ≡ c g / c g , SM , ˜ κ g ≡ 3˜ c g / 2 c g , SM g σ ( gg → h ) = | κ g | 2 + | ˜ κ g | 2 = κ 2 κ 2 t + 2 . 6 ˜ t + 0 . 11 κ t ( κ t − 1) σ ( gg → h ) SM Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 13 / 42

Constraints from h → γγ h → γγ generated at one loop Have effective potential α 3 α h h v F µν F µν − ˜ v F µν � F µν V eff = − c γ c γ π 2 π γ γ c γ , ˜ c γ given in terms of loop functions h h κ γ ≡ c γ / c γ, SM , ˜ κ γ ≡ 3˜ c γ / 2 c γ, SM W b, t γ γ Γ( h → γγ ) = | κ γ | 2 + | ˜ κ γ | 2 = (1 . 28 − 0 . 28 κ t ) 2 + (0 . 43 ˜ κ t ) 2 Γ( h → γγ ) SM Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 14 / 42

LHC input CMS Preliminary -1 -1 2.0 s = 7 TeV, L ≤ 5.1 fb s = 8 TeV, L ≤ 19.6 fb g κ , κ κ g γ 1.8 1.6 1.4 Naive weighted average of ATLAS, CMS 1.2 1.0 0.8 κ g , WA = 0 . 91 ± 0 . 08 , κ γ, WA = 1 . 10 ± 0 . 11 0.6 0.4 g /γ, WA = | κ g /γ | 2 + | ˜ We set κ 2 κ g /γ | 2 0.2 0.0 0.0 0.5 1.0 1.5 2.0 κ γ [CMS-PAS-HIG-13-005] Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 15 / 42

Electron EDM γ t γ h e EDM induced via “Barr-Zee” diagrams [Weinberg 1989, Barr & Zee 1990] | d e / e | < 8 . 7 × 10 − 29 cm (90% CL) [ACME 2013] with ThO molecules | ˜ κ t | < 0 . 01 Constraint on ˜ κ t vanishes if Higgs does not couple to electron Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 16 / 42

Neutron EDM γ g g h t t γ g t h h g g q q Three operators; will mix, need to perform RGE analysis � � � d n κ t + 5 . 1 · 10 − 2 κ t ˜ e = (1 . 0 ± 0 . 5) − 5 . 3 κ q ˜ κ t � + (22 ± 10) 1 . 8 · 10 − 2 κ t ˜ · 10 − 25 cm . κ t w ∝ κ t ˜ κ t subdominant | d n / e | < 2 . 9 × 10 − 26 cm (90% CL) [Baker et al., 2006] Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 17 / 42

Mercury EDM g t g h q Diamagnetic atoms also provide constraints | d Hg / e | < 3 . 1 × 10 − 29 cm (95% CL) [Griffith et al., 2009] Dominant contribution from CP-odd isovector pion-nucleon interaction � � � � d Hg κ t − 3 . 2 · 10 − 2 κ t ˜ 4 +8 · 10 − 29 cm = − 3 . 1 ˜ κ t − 2 e Again, w ∝ κ t ˜ κ t subdominant, but does not vanish if Higgs does not couple to light quarks Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 18 / 42

Other low-energy constraints s b h No effects in dim. six operators t t s b s b O (100) effects allowed by data h γ t b µ + t h O (100) effects allowed by data ¯ B s W t µ − s Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 19 / 42

Combined constraints on top coupling Assume SM couplings to electron and light quarks Future projection for 3000fb − 1 @ high-luminosity LHC [J. Olsen, talk at Snowmass Energy Frontier workshop] Factor 90 (300) improvement on electron (neutron) EDM [Fundamental Physics at the Energy Frontier, arXiv:1205.2671] Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 20 / 42

Combined constraints on top couplings Set couplings to electron and light quarks to zero Contribution of Weinberg operator will lead to strong constraints in the future scenario Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 21 / 42

CPV in hbb couplings Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 22 / 42

Collider constraints Modifications of gg → h , h → γγ due to κ b � = 1, ˜ κ b � = 0 are subleading ⇒ Main effect: modifications of branching ratios / total decay rate � � Br( h → b ¯ κ 2 κ 2 b + ˜ b ) SM Br( h → b ¯ b b ) = � � Br( h → b ¯ κ 2 κ 2 1 + b + ˜ b − 1 b ) SM Br( h → X ) SM Br( h → X ) = � � Br( h → b ¯ κ 2 κ 2 1 + b + ˜ b − 1 b ) SM Use naive averages of ATLAS / CMS signal strengths ˆ µ X for X = b ¯ b , τ + τ − , γγ , WW , ZZ µ X = Br( h → X ) / Br( h → X ) SM ˆ Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 23 / 42

RGE analysis of the b -quark contribution to EDMs g EDMs suppressed by small bottom Yukawa ≈ 3 scale uncertainty in CEDM Wilson coefficient b Two-step matching at M h and m b : g h q Mixing into Integrate out Higgs Matching onto O q qq ¯ O q q σ µν T a q ¯ bi σ µν γ 5 T a b 4 = ¯ mb 1 = ¯ bi γ 5 b O q 6 = − i q σ µν T a γ 5 qG a gs ¯ 2 µν Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 24 / 42

RGE analysis of the b -quark contribution to EDMs γ b γ h q � α s � 3 γ (0) 14 γ (0) 48 γ (0) (4 π ) 2 Q q log 2 m 2 log 3 m 2 C q 5 ( µ b ) = − 4 αα s h + O ( α 4 b h + 87 b s ) , M 2 4 π 48 M 2 � α s � 2 γ (0) 14 γ (0) log 2 m 2 C q h + O ( α 3 6 ( µ b ) = s ) , 48 b M 2 4 π 8 � α s � 2 γ (1) log m 2 h + O ( α 3 C 7 ( µ b ) = 5 , 11 s ) . b M 2 4 π 2 Joachim Brod (JGU Mainz) Nonstandard Yukawa Couplings 25 / 42