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THE SEE-SAW MECHANISM PREDICTIONS WITHIN THE SU (5) FRAMEWORK

THE SEE-SAW MECHANISM PREDICTIONS WITHIN THE SU (5) FRAMEWORK. Ilja Doršner Institut “Jožef Stefan” October 12, 2007. I.D. and Irina Mocioiu, arXiv:0708.3332  [hep-ph] . I.D. and Pavel Fileviez P é rez, hep-ph/0612216 , hep-ph/0606062 .

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THE SEE-SAW MECHANISM PREDICTIONS WITHIN THE SU (5) FRAMEWORK

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  1. THE SEE-SAW MECHANISM PREDICTIONS WITHIN THE SU(5) FRAMEWORK Ilja Doršner Institut “Jožef Stefan” October 12, 2007 • I.D. and Irina Mocioiu, arXiv:0708.3332 [hep-ph]. • I.D. and Pavel Fileviez Pérez, hep-ph/0612216, hep-ph/0606062. • I.D., P.F.P. and German Rodrigo, hep-ph/0607208; I.D., P.F.P. and Ricardo Gonzalez Felipe, hep-ph/0512068; I.D. and P.F.P., hep-ph/0504276.

  2. OUTLINE OF THE PRESENTATION • FERMION MASSES IN SU(5) • PROTON DECAY • UNIFICATION • SIMPLE SU(5) MODELS AND THEIR PREDICTIONS • CONCLUSIONS

  3. FERMION MASSES…

  4. NEUTRINO MASSES The Standard Model (SM) content requires higher-dimensionaloperators† (d > 4 ) to accommodate massive neutrinos. The lowest order¤ one is the so-called d = 5operator. ______________________† S. Weinberg (1979).

  5. mν SEESAW MECHANISM (Why are the mν elements so small?) Λ • TYPE I■: fermion(s) ―(1,1,0) • TYPE II†: scalar ―(1,3,1) • TYPE III‡: fermion(s) ―(1,3,0) The SM transformation properties ( SU(3) , SU(2) , U(1) ) ______________________■ P. Minkowski (1977); T. Yanagida (1979); M. Gell-Mann, P. Ramond and R. Slansky (1979); R.N. Mohapatra and G. Senjanović (1980). † G. Lazarides, Q. Shafi and C. Wetterich (1981); R.N. Mohapatra and G. Senjanović (1981). ‡ R. Foot, H. Lew, X.G. He and G.C. Joshi (1989); E. Ma (1998).

  6. SM SU(5) SEESAW MECHANISM IN SU(5) • TYPE I: fermion(s) ― (1,1,0) 1, 24‡ • TYPE II: scalar ― (1,3,1) 15† • TYPE III: fermion(s) ― (1,3,0) 24‡ ______________________† I.D. and P.F.P. (2005); I.D., P.F.P. and G. Rodrigo (2006); I.D., P. F.P. and R. Gonzalez Felipe (2006); F.R. Joaquim, A. Rossi (2006);I.D. and I. Mocioiu (2007). ‡ B. Bajc and G. Senjanović (2006); I.D. and P.F.P. (2006), B. B., M. Nemevšek and G. S. (2007), P.F.P. (2007).

  7. Y2‹ΨD›2/Mρ24 νL νL TYPE I SEESAW IN SU(5) 5H(5H, 45H)  ‹ΨD› ‹ΨD› 5a 1 (24)   (νL)a (1,1,0) (= ρ24) Mρ24 (1,1,0) (= ρ24) νL YUKAWA YUKAWA spin 1/2 spin 0 mννLνL ≡

  8. TYPE II SEESAW IN SU(5)† ‹Φa› 15H  (1,3,1) (= Φa) (νL)a (Y)ab (νL)b (Y)ab‹Φa› νL νL ______________________† F. Buccella, G.B. Gelmini, A. Masiero and M. Roncadelli (1984).

  9. TYPE II SEESAW IN SU(5)† ‹ΨD› ‹ΨD› m (1,3,1) (= Φa) (νL)a (Y)ab (νL)b Y m‹ΨD›2/(MΦa)2 νL νL ______________________† I.D. and P.F.P. (2005).

  10. TYPE III SEESAW IN SU(5)‡ ‹ΨD› ‹ΨD› 24  νL (1,3,0) (= ρ3) Mρ3 (1,3,0) (= ρ3) νL Y Y Y2‹ΨD›2/Mρ3 νL νL ______________________‡ B. Bajc and G. Senjanović (2006).

  11. CHARGED FERMION MASSES IN SU(5) ______________________H. Georgi and S.L. Glashow (1974).

  12. FERMION MASSES IN SU(5) • Up quark masses • Down quark and charged lepton masses • Neutrino masses

  13. FERMION MASSES IN SU(5) (type II seesaw)

  14. SU(5) SYMMETRY BREAKING MGUT ~1014–17 GeV SU(3) × SU(2) × U(1) SU(5): αGUT α3 α2 α1 SU(3) × U(1)em SU(3) × SU(2) × U(1): 102 GeV

  15. SU(3) × SU(2) × U(1)SYMMETRY BREAKING‡ SU(3) × SU(2) × U(1): α3 α2 α1 αem SU(3) × U(1)em ______________________‡ I.D. and I. Mocioiu (2007); H. Georgi and M. Machacek (1985); M.S. Chanowitz and M. Golden (1985).

  16. CHARGED FERMION MASSES (non-renormalizable terms with 5H and Σ≡ 24H•) ______________________•J.R. Ellis and M.K. Gaillard (1979).

  17. SIMPLE SU(5) MODELS 5H or 45H 5H + 45H MU, MD, ME RENORMALIZABLE NONRENORMALIZABLE NEUTRINO MASSES TYPE I SEESAW TYPE II SEESAW TYPE I + TYPE III SEESAW

  18. PROTON DECAY IN SU(5) (vector gauge boson d=6 contributions†) ______________________† P.F.P. hep-ph/0403286 ; I.D. and P.F.P. hep-ph/0409095.

  19. PROTON DECAY

  20. PROTON DECAY INSU(5) (vector gauge boson d=6 contributions)

  21. PROTON DECAY IN SU(5) (vector gauge boson d=6 contributions†) ______________________†S. Nandi, A. Stern and E.C.G. Sudarshan (1982).

  22. PROTON DECAY IN GUTS (vector gauge boson d=6 contributions‡) ______________________‡ I.D. and P. F.P., “How long could we live?” Phys. Lett. B625 (2005).

  23. UNIFICATION OF GAUGE COUPLINGS IN THE SM DATA: PDG 2006

  24. UNIFICATION OF GAUGE COUPLINGS

  25. Georgi-Glashow SU(5)‡ HIGGS SECTOR: The Georgi-Glashow GUT content MATTER SECTOR: GG model is ruled out by low-energy experiments. ______________________‡Georgi and Glashow (1974)

  26. Doršner-Fileviez Pérez SU(5)‡ HIGGS SECTOR: The Georgi-Glashow GUT content The Doršner-Fileviez Pérez SU(5)‡ content MATTER SECTOR: a = 1,2,3 EXTRA SCALAR: ______________________‡ I.D. and P.F.P., hep-ph/0504276; I.D., P.F.P. and R.G. Felipe hep-ph/0512068; I.D., P.F.P. and G. Rodrigo hep-ph/0607208.

  27. PREDICTIONS: i) Light leptoquarks Φb. ii) Light Σ3 scalar. iii) max(τptho.)~ 10 τpexp..

  28. Georgi-JarlskogSU(5)‡ HIGGS SECTOR: The Georgi-Glashow GUT content The Georgi-Jarlskog SU(5)‡ content MATTER SECTOR: a = 1,2,3 EXTRA SCALAR: ______________________‡ I.D. and P.F.P., hep-ph/0504276;I.D. and Irina Mocioiu, arXiv:0708.3332 [hep-ph].

  29. PREDICTIONS: If certain class of d=6 proton decay operators is not suppressed then the model with the Georgi-Jarlskog particle content with the type I seesaw is ruled out! NOTE:

  30. Bajc-Senjanović SU(5)‡ HIGGS SECTOR: The Georgi-Glashow GUT content The Bajc-Senjanović SU(5)‡ content MATTER SECTOR: a = 1,2,3 EXTRA MATTER: ______________________‡ B. Bajc and G. Senjanović, hep-ph/0612029.

  31. LIGHT TRIPLETS‡ ______________________‡ B. Bajc and G. Senjanović, hep-ph/0612029; I.D. and P.F.P. hep-ph/0612216; B. Bajc M. Nemevšek and G. Senjanović, hep-ph/0703080.

  32. Doršner-MocioiuSU(5)‡ HIGGS SECTOR: The Georgi-Glashow GUT content The Doršner-Mocioiu SU(5)‡ content MATTER SECTOR: a = 1,2,3 EXTRA SCALARS: ______________________‡ I.D. and Irina Mocioiu, , arXiv:0708.3332 [hep-ph].

  33. LIGHT SCALARS‡ ______________________‡ I.D. and Irina Mocioiu, , arXiv:0708.3332 [hep-ph].

  34. Let us fix the mass of both the scalar triplet Φa and fermionic triplet ρ3 at300 GeV in order to insure their detection at LHC and then find the maximal value of the GUT scale (or minimum of B12 coefficient) that one can have in both cases. This exercise yields the following:

  35. CONCLUSIONS 1) The simplest SU(5) models with the type I seesaw mechanism are ruled out under the usual assumptions. 2) There exist realistic nonSUSY SU(5) GUTs that could be tested at LHC. Three specific SU(5) GUT models that aim in that direction are: (i) nonrenormalizable SU(5) with the type II seesaw, (ii) renormalizable SU(5) with the type II seesaw,and (iii) nonrenormalizableSU(5) with the hybrid–type I + type III–seesaw scenario.

  36. CONCLUSIONS (CONTINUED) In all three cases interesting signatures include (in)direct observation of exotic light particles, enhanced rates for specific rare processes, observable proton decay and, most importantly, correlation between these processes and the parameters in the neutrino sector. Latter could also allow us to experimentally probe the underlying seesaw mechanism. Even though these models are extremely fine tuned they are very predictive and hence verifiable as well as falsifiable.

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