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Chiral freedom and the scale of weak interactions

Chiral freedom and the scale of weak interactions. proposal for solution of gauge hierarchy problem. model without fundamental scalar new antisymmetric tensor fields mass term forbidden by symmetry chiral couplings to quarks and leptons chiral couplings are asymptotically free

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Chiral freedom and the scale of weak interactions

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  1. Chiral freedomand the scale ofweak interactions

  2. proposal for solution of gauge hierarchy problem • model without fundamental scalar • new antisymmetric tensor fields • mass term forbidden by symmetry • chiral couplings to quarks and leptons • chiral couplings are asymptotically free • weak scale by dimensional transmutation

  3. antisymmetric tensor fields • two irreducible representations of Lorentz – symmetry : (3,1) + (1,3) • complex representations : (3,1)* = (1,3) • similar to left/right handed spinors

  4. chiral couplings to quarks and leptons • most general interaction consistent with Lorentz and gauge symmetry : ß are weak doublets with hypercharge • consistent with chiral parity : d R , e R , ß - have odd chiral parity

  5. no mass term allowed for chiral tensors • Lorentz symmetry forbids (ß+)* ß+ • Gauge symmetry forbids ß+ ß+ • Chiral parity forbids (ß-)* ß+

  6. kinetic term • does not mix ß +and ß – • consistentwith all symmetries, including chiral parity

  7. quartic couplings add gauge interactions and gauge invariant kinetic term for fermions …

  8. classical dilatation symmetry • action has no parameter with dimension mass • all couplings are dimensionless

  9. B - basis • B –fields are unconstrained • six complex doublets • vectors under space – rotations • irreducible under Lorentz -transformations

  10. free propagator inverse propagator has unusual form : propagator is invertible ! except for pole at q 2 = 0

  11. energy density positive for longitudinal mode vanishes for transversal modes ( borderline to stability ) unstable secular classical solutions in free theory

  12. asymptotic freedom

  13. evolution equations for chiral couplings

  14. evolution equations for top coupling fermion anomalous dimension tensor anomalous dimension no vertex correction asymptotic freedom ! Avdeev,Chizhov ;93

  15. dimensional transmutation Chiral coupling for top grows large at chiral scale Λch This sets physical scale : dimensional transmutation - similar to ΛQCD in strong QCD- gauge interaction

  16. spontaneous electroweaksymmetry breaking

  17. top – anti-top condensate • large chiral coupling for top leads to large effective attractive interaction for top quark • this triggers condensation of top – anti-top pairs • electroweak symmetry breaking : effective Higgs mechanism provides mass for weak bosons • effective Yukawa couplings of Higgs give mass to quarks and leptons cf : Miranski ; Bardeen, Hill, Lindner

  18. Schwinger - Dyson equationfor top quark mass solve gap equation for top quark propagator

  19. SDE for B-B-propagator

  20. gap equation for top quark mass has reasonable solutions for mt

  21. two loop SDE for top-quark mass contract B- exchange to pointlike four fermion interaction tL tR

  22. effective interactions • introduce composite field for top- antitop bound state • plays role of Higgs field • new effective interactions involving the composite scalar φ

  23. effective scalar tensor interactions

  24. chiral tensor – gauge boson - mixing and more …

  25. massive chiral tensor fields

  26. effective cubic tensor interactions generated by electroweak symmetry breaking

  27. propagator corrections from cubic couplings non – local !

  28. effective propagator for chiral tensors massive effective inverse propagator : pole for massive field mass term :

  29. massive spin one particles • new basis of vector fields: • standard action for massive vector fields • classical stability !

  30. classical stability • massive spin one fields : stable • free theory : borderline stability/instability, actually unstable ( secular solutions , no ghosts) • mass term moves theory to stable region • positive energy density

  31. phenomenology

  32. new resonances at LHC ? • production of massive chiral tensors at LHC ? • signal : massive spin one resonances • rather broad : decay into top quarks • relatively small production cross section : small chiral couplings to lowest generation quarks , no direct coupling to gluons

  33. mixing of charged spin one fields • modification of W-boson mass • similar for Z – boson • watch LEP – precision tests !

  34. mixing between chiral tensorand photon

  35. Pauli term contributes to g-2 suppressed by • inverse mass of chiral tensor • small chiral coupling of muon and electron • small mixing between chiral tensor and photon

  36. effective interactions fromchiral tensor exchange • solve for Sμ in presence of other fields • reinsert solution

  37. general solution propagator for charged chiral tensors

  38. momentum dependent Weinberg angle

  39. new four fermion interactions typically rather small effect for lower generations more substantial for bottom , top !

  40. mixing of chiral tensors with ρ - meson could contribute to anomaly in radiative pion decays

  41. conclusions • chiral tensor model has good chances to be consistent • mass generation needs to be understood quantitatively • interesting solution of gauge hierarchy problem • phenomenology needs to be explored ! • if quartic couplings play no major role: • less couplings than in standard model Predictivity !

  42. end

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