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Explore the evolution of the Universe to the present Inert phase in Two Higgs Doublet Models (2HDMs) with Z2 symmetry, focusing on various vacua and thermal evolutions. Learn about the Brout-Englert-Higgs mechanism, CP violation, Yukawa couplings, and mass generation in the Standard Model. Discover the Inert Model with dark doublets and potential vacuum states, including conservation of Z2 symmetry and dark matter candidates.
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USTROŃ 2009 15.09. 2009 Evolution of the Universe to the present Inert phase 2HDMs Z2 symmetry The Inert Model Various vacua Today= Inert phase Thermal evolutions Maria Krawczyk University of Warsaw I. Ginzburg, K. Kanishev (Novosibirsk University), D.Sokołowska (University of Warsaw)
Brout-Englert-Higgs mechanism Spontaneous breaking of EW symmetry SU(2) x U(1) → U(1) QED Standard Model Doublet of SU(2): vHi Masses for W, Z (tree =1) , no mass for the photon Fermion masses via Yukawa interaction Higgs particle HSM - spin 0, neutral, CP even couplings to WW/ZZ, Yukawa couplings to fermions mass selfinteraction unknown
Brout-Englert-Higgs mechanism Spontaneous breaking of EW symmetry SU(2) x U(1) → ? Two Higgs Doublet Models Two doublets of SU(2) (Y=1, =1) - Φ₁ , Φ₂ Masses for W, Z , no mass for photon? Fermion masses via Yukawa interaction – various models: Model I, II, III, IV,X,Y,... 5 scalars: H+ and H- and neutrals: - CP conservation: CP-even h, H & CP-odd A - CP violation: h1,h2,h3 with undefinite CP parity* Sum rules (relative couplings to SM )
2HDM Potential Lee'73, Haber, Gunion, Glashow, Weinberg, Paschos, Despande, Ma, Wudka, Branco, Rebelo, Lavoura, Ferreira, Barroso, Santos, Bottela, Silva, Diaz-Cruz, Grimus, Ecker, Ivanov, Ginzburg, Krawczyk, Osland, Nishi, Nachtmann, Akeroyd, Kanemura, Kalinowski, Grządkowski ,Hollik, Rosiek.. V = λ1(Φ₁†Φ₁)²+λ₂(Φ₂†Φ₂)²+λ₃(Φ₁†Φ₁)(Φ₂†Φ₂) + λ₄(Φ₁†Φ₂)(Φ₂†Φ₁)+ [λ₅(Φ₁†Φ₂)²+h.c] + [(λ₆(Φ₁†Φ₁)+λ₇(Φ₂†Φ₂))(Φ₁†Φ₂)+h.c] -m²₁₁(Φ₁†Φ₁)-m²₂₂(Φ₂†Φ₂)-[m²₁₂(Φ₁†Φ₂)+h.c.] Z₂ symmetry transformation: Φ₁→Φ₁ Φ₂→ - Φ₂ Hard Z₂ symmetry violation: λ₆, λ₇ terms Soft Z₂ symmetry violation: m²₁₂ term (Re m²₁₂=µ²) Explicit Z₂ symmetry in V: λ₆, λ₇, m²₁₂=0
- If Z2 symmetry holds in the Lagrangian L no CP violation in the scalar sector Lee' 73 Glashow, Weinberg'77, Paschos '77 Despande, Ma' 78 - Softly broken Z2→ Branco, Rebelo '85 CP violation possible, tree-level FCNC absent, Decoupling and non-decoupling possible Haber'95 - Hard breaking Z2→ CP violation possible [* even without CP mixing] Lavoura, Silva' 94 ; Kanishev, MK, Sokołowska' 2008 tree-level FCNC Z2 symmetry: Φ₁ → Φ₁ Φ₂→- Φ₂
Yukawa interactions (with or withoutZ2 symmetry) Model I - only Φ₁interacts with fermions Model II - Φ1 couples to down-type fermions d Φ2couplesup-type fermions u Model III - both doublets interact with fermions Model X - leptons interact with one doublet, quarks with other Top 2HDM – only top couples to one doublet + Extra dim 2HDM models ...
Inert or Dark 2HDM Ma'78 Barbieri'06 Z2 symmetry under Φ₁ → Φ₁ Φ₂→- Φ₂ both in L and in vacuum → Inert Model → Φ₁ as in SM, with Higgs boson h (SM-like) → Φ₂ - no vev, with 4 scalars (no Higgs bosons!) no interaction with fermions (inert doublet) Conservation of the Z2 symmetry; only Φ₂ has odd Z2 -parity → The lightest scalar – a candidate for dark matter (Φ2 dark doublet with dark scalars) . Conserved Z₂- parity only Φ₂ has Z₂-odd parity. Today <Φ₁T >= (0,v) <Φ2T >= (0,0)
Vacua for the potential with explicit Z2 symmetry and real parameters Finding extrema: VΦ₁Φ₁Φ₁and Φ₁ → Φ2 Finding minima → global minimum = vacuum Positivity (stability) constraints (for λ₆, λ₇, m²₁₂=0) Extremum fulfilling the positivity constraints with the lowest energy = vacuum Ginzburg, Kanishev, MK, Sokołowska'09
Possible vacuum states (V with explicit Z2) The most general vacuum state v1, v2, u , ξ - real, 0 v2 =v12 +v22 +u2 = (246 GeV)2 Inert I u = v2 = 0 Normal (CP conserving) N u = ξ = 0 Charge Breaking Ch u≠0 v2 =0 [ Vacuum B u = v1 = 0]
Various vacua on (λ4 , λ5) plane Positivity constrains on V: X=λ1λ2+λ3>0λ4 ± λ5 > - X Inert (or B) Y = MH+2 2/v2 Charge Breaking Ch Normal Note the overlap of the Inert with N and Ch !
TODAY 2HDM with explicit Z2 symmetry Φ₁ → Φ₁ Φ₂→- Φ₂ Model I (Yukawa int.) Charged breaking phase ? photon is massive, el.charge is not conserved... → no Neutral phases: Normal ok, many data, but no DM Inert OK! there are some data B no, all fermions massless, no DM
Inert Model (Dark 2HDM) vs dataMa..' 78, Barbieri.. ' 2006 Exact Z₂ symmetry in L and in vacuum → Z2-parity: odd is only Φ₂ Φ₁ Nonzero vev has only doublet Φ₁ (Higgs doublet) only it couples to fermions (Model I) SM-like Higgs boson h M2h= m112 = 1 v2 Φ₂ Zero vev for Φ₂ (scalar doublet) and no Yukawa int. Four scalars with odd Z₂-parity (dark scalars D) The lightest dark scalar - stable
Dark scalars D = H+,H-,H,A Masses D couple to V = W/Z (eg. AZH, H⁻ W⁺H), not to V V! Selfcouplings DDDD proportional to Couplings between Higgs boson h and D proportional toM2D + m222 /2
Intert Model – dark scalar massesusing X (positivity) andY = MH+2 2/v2 here H+ the heaviest here H is the dark matter candidate (λ5 0)
Testing Inert Model To consider properties of SM-like h (light and heavy) properties of dark scalars (produced only in pairs!) DM candidate Colliders signal/constraints Barbieri et al '2006 for heavy h Cao, Ma, Rajasekaren' 2007 for a light h
Dark 2HDM: LEP II exclusion Lundstrom et al 0810.3924 LEP II + WIMP Mh= 200 GeV MA- MH > 8 GeV
Inert Model: constraints LEP+DM → LHC E. Dolle, S. Su, 0906.1609 [hep-ph] LEP (exclusion and EW precision data) + relic density using MicroOMEGA/CalCHEP S=H Su, CERN, August 2009
Dark 2HDM – additional decays for h Ma' 2007
Conclusion on gamma lines Gustafsson et al.2007: Striking DM line signals -promising features to search with GLAST Mass of: H = 40-80 GeV, H+ = 170 GeV, A = 50-70 GeV, h = 500 and 120 GeV Honorez, Nezri, Oliver, Tytgat 2006-7: H as a perfect example or arcgetype of WIMP – within reach of GLAST (FERMI) Here mass of h = 120 GeV, large mass H+ close to A = 400 - 550 GeV
Evolution of the Universe – different vacua in the past ? We consider 2HDM with an explicit Z2 symmetry assuming that today the Inert Model is realized. Useful parametrization with k and δ Yukawa interaction – Model I → all fermions couple only to Φ₁
Possible vacua: Ch Inert B u=0 N Depending on value of δ → a true vacuum (with the minimal energy) u≠0
Termal corrections of parameters Matsubara method (temperature T>> m2) – -only quadratic (mass) parameters change with T δ(T) with T → different phases
Phase transitions from the EW symmetric phase For to the present INERT phase
Conclusions Rich content of 2HDMs Intert Model in agreement with present data – soon tests at FERMI and LHC What was in the Past? Various scenarios Can we find clear signals ? excluded if DM neutral !
Conclusions 2HDM – a great laboratory for physics BSM In many Standard Models SM-like scenarios can be realized: [Higgs mass >114 GeV, SM tree-level couplings] In models with two doublets: - MSSM with decoupling of heavy Higgses → LHC-wedge - 2HDM with and without CP violation both h or H can be SM-like - Dark 2HDM (Intert Model) Loop effects = a window to heavy sector
SM-like scenarios In many Standard Models SM-like scenarios are realized (Higgs mass >114 GeV, SM tree-level couplings) In models with two doublets: - MSSM with decoupling of heavy Higgses → LHC-wedge - 2HDM with and without CP violation both h or H can be SM-like - Dark 2HDM (Intert Model)
Dark 2HDM: h