1. THE CONNECTION BETWEEN NEUTRINO EXPERIMENTS AND LEPTOGENESIS Alicia Broncano Berrocal MPI

2. Non-zero  Neutrino Masses and Mixings ! Cosmological Baryon Asymmetry Data from the sun and cosmic rays LEPTOGENESIS (Fukugita,Yanagida,1986) SEESAW MODEL (Minkowski, 1977; Gell-Mann, Ramond, Slansky, 1979) First evidence of physics beyond the SM m = 0 in the minimal SM by B-L accidental symmetry. New Physics Scale B-L We study the low energy implications of seesaw model and analize what information could they provide about the full theory

3. SEESAW MODEL: + singlet under SM gauge group Mass Lagrangian: It can be integrated out and obtain

4. SEESAW MECHANISM When, predicts  -decay B-L at low energies Exper. data require 2 or more families (1 generation : m 1 = m 2 = 0; m 3 = 0) complex : CP-violation at high and low energies

5. The seesaw contains the fundamental ingredients the cosmological baryon asymmetry (WMAP, 2003) Baryogenesis requires physics beyond the SM with 1. New sources of CP :  CKM phase too small 2. B-L at T > T EW ~ 100 GeV, (Fukugita, Yanagida, 1986) LEPTOGENESIS =,,,,,,,,, SEESAW MODEL

6. The dependence of leptogenesis on and allows to relate it to neutrino seesaw masses. ( Davidson&Ibarra,2002; Pilaftsis et.al, 2003; Giudice et.al, 2003; Buchmüller et.al.,2004...) Depend on the seesaw scenario, if So far, data on -masses make leptogenesis compatible with……………………………………, but not enough data to constrain and Let us see why…

7. 3961533 152822 n(n-1)/2n(n+3)/2n(n´-1)n+n´+nn´nn´ PhasesModuliPhasesModuli Low energyHigh energy Families Count the number of physical parameters in the leptonic mass Lagrangians NOT ENOUGH LOW-ENERGY MEASUREMENTS (Santamaria,1993)

8. High energy: 8 moduli + 2 phases Low energy: 5 moduli + 1 phase

9. Is there a model independent way to recover the seesaw parameters ?

10. THE SEESAW EFFECTIVE LAGRANGIAN As, is integrated out Seesaw effective Lagrangian

11. Take next term in the expansion: although suppressed ( )*, very interesting for theory * Notice that is of... … but enhanced by L/E in oscillations

12. term (AB,Gavela,Jenkins,2002) Conserves L only tree-level operator from

13. Lagrangian in canonical form and in mass basis: modifies -kinetic energy when Non diagonal matrix in flavor space ( doesn’t change at ) Majorana mass eigenstates:

14. CKM-like unitary matrix (from m -diagonalization) Non-unitary mixing matrix Weak currents change Exotic couplings Remnant of the mixing with heavy neutrinos

15. Which could appear, for instance, in: In 2x2 scenario 3 moduli 1 phase 8 moduli + 2 phases With,, and The same as in the full theory

16. 9159 33 282822 n(n-1)n(n+2)n(n´-1)n+n´+nn´nn´ PhasesModuliPhasesModuli Low energyHigh energy Families By considering, we recover the same number of parameters as in the original theory

17. When, allows to express the seesaw parameters in terms of low energy quantities

18. (Casas& Ibarra,2001) For instance, Unknown orthogonal matrix Considering only, the unknown information about is encoded by some matrix. Considering, Depends on both &

19. Leptogenesis CP -asymmetry Complicated function, but it exists :  Lepto CP -phase depends on all low-energy phases For instance, (AB,Gavela,Jenkins,2003) (No Dirac or Majorana phases)

20. Limiting cases eigenvalues degenerate if (Davidson & Ibarra,2002) eigenvalues degenerate ( ) if ??? if (Hambye et al,2004)

21. Observational problem: Even lowering the seesaw scale at TeV: Very far from present bounds Flavor Universality Rare decays Neutrino oscillations (NOMAD) (Bergmann & Kagan, 1999) (Bernabeu et al, 1996)

22. SEESAW BASED ALTERNATIVES Assume other models of new physics which Decrease the number of parameters: GUT ( Branco et. al., 2002; Allbright & Barr,2004…) Flavor symmetries (Frampton et. al, 2002; Xing 2002;..) Provide other observables SUSY (Casas & Ibarra, 2001; Davidson & Ibarra,2002;…) Minimal effective Lagrangian generic for all models

23. The minimal tree level effective Lagrangian provides the theoretical connection with and At one loop, there are more low-energy effects. For instance, in the RGE of the leptonic mixing matrix

24. A possible symmetry between quarks and leptons, is not evident when comparing: Could they be similar at some high scale and have changed through renormalization effects ? Weak int. dominate lepton RGE: flavor mixing Strong int. dominate quarks RGE: no flavor mixing

25. Evolution of the leptonic mixing matrix calculated from the RGE of to (Babu et.al,1993; Casas et.al,2000; Antusch et.al,2003,…) Evolution of the leptonic mixing matrix calculated in the full seesaw theory has also terms of the type in effective theory (Pilaftsis,Kniehl,2002)  Two generations and no CP-violation

26. The connection with the RGE of the leptonic mixing in the full seesaw should consider the dominant flavor changing terms in the effective theory

27. d=6 operators generated by radiative mixing ( does not mix)  = M:  =100 GeV: Renormalization Group evolution

28. For instance, two insertions of Generate the coefficient of the operator When, contributes to the m e Non diagonal matrix in flavor space

29. Necessary to define the one loop matrix Thus, at one loop to From m e diagonalization from m diagonalization

30. Two generations and no CP-violation : term : full theory term (similar in CKM RGE) : due to the non-unitarity of (AB,Gavela,Jenkins,2004)

31. OVERLOOK Generic relationship between low-energy quantities and seesaw model and leptogenesis from Very suppressed exotic couplings from (AB,Gavela,Jenkins,2002) & in terms of & Lepto CP-asym depends on all phases in & eigenvalues degenerate (AB,Gavela,Jenkins,2003) connects full seesaw & low-energy RGE’s of leptonic mixing matrix (AB,Gavela,Jenkins,2004)

32. Basic ingredients Leptonic  measured CP -violation 2  0 -decay detected B-L violation LEPTOGENESIS SEESAW MODEL