Radiative Generation of the Higgs Potential

Transcription

1 Radiative Generation of the Higgs Potential 1 EUNG JIN CHUN Based on with H.M.Lee and S. Jung

2 Disclaimer LHC finds Nature is unnatural. 2 May entertain with Naturally unnatural ideas. EW scale from zero potential?

3 (Un)Natural assumptions No quadratic divergences: renormalized away (DR). 3 No heavy particles with large couplings with SM H field. A Natural UV theory: no/supersymmetric heavy fields coupling to H. H as pngb without T, W?

4 SU(2) U(1) Higgs: Weinberg 1967 Standard Model Higgs 4 Two Higgs parameters: fundamental?

5 Instability of Higgs potential Vanishing H at New physics? 5 Degrassi, et.al.,

6 Colman-Weinberg Mechanism 6 Spontaneous breaking of a gauge symmetry by quantum correction. Coleman-Weinberg 1973 Generating a scale by dimensional transmutation: Minimum at <Á> << UV :

7 EWSB from CW? Application to SM 7 Minimization condition: With no (small) top Yukawa too light Higgs: With measured top Yukawa unstable minimization condition:

8 Extensions CW mechanism for SSB in abelian scalar theory. 8 Scale-invariant SM U(1) X : ¹ H2 ( )=0. Hempfling 1996 Application to SM U(1) B-L connected to the origin of neutrino mass. Iso, Okada, Orikasa, 2009

9 Type I seesaw with B-L Anomaly free B-L requires three right-handed neutrinos explaining the smallness of neutrino masses B-L breaking without ¹ : a classic example of CW. from y N!! RHN mass: M N = y N < > after B-L breaking.

10 Vanishing potential at Small negative H from quantum correction! 10 Iso, Orikasa, Vanishing at! EJC, Lee, Jung,

11 Radiative breaking of SM (B-L) Quantum generation of the Higgs potential: 11

12 CW mechanism for B-L breaking CW potential for B-L : 12 Minimum obtained for» g 4 B-L <<1 The B-L scalar and Z masses:

13 Running of & V 0 13 V tree ( ) =0 two input parameters at M I : g B-L & y N Loop-generated has to be small enough to meet the minimization condition. changes sign

14 Generation of H Gauge kinetic mixing at oneloop: 14 SM B-L scalar mixing term:

15 Technical details and results 15 Two free parameters : g B-L & y N For given g B-L & y N at M I run RGE down to find v satisfying the CW minimization condition: Then, check LHC pushes up the Z : v > 3 TeV. We find one parameter family of solutions in the g B-L y N plane.

16 y N g B-L at v 16

17 One-loop 17

18 Prediction on v (M N ) 18 (Note) v >10 9 GeV possible for g B-L < 10-3.

19 B-L scalar mass 19 Negligible mixing between the SM and B-L scalars. B-L scalar decay, Á hh, with a very narrow width.

20 Bounds on M N from Higgs mass 20 One-loop correction to ¹ H 2 from y º : Vissani, 1997 Two-loop correction to ¹ 2 H from Z couplings to top and RHN: Iso, et.al, 2009 Thermal non-resonant leptogenesis: Davidson-Ibarra, 2002 Giudice, et.al., 2003

21 Conclusion 21 The Higgs parameters H & ¹ H 2 may not be fundamental. Vanishing H at a high scale + dynamical generation of a scale Assumption of fully vanishing potential at a UV scale. A nicely working example of SM (B-L) explaining neutrino mass: Radiative breaking of EW and B-L from two input parameters, y N & g B-L predictions on M N & M Á. Toward a complete story no quadratic divergence and no quadratic correction from the Higgs coupling to UV scale fields?