Neutrino Masses and the Quest for Unification

1. Neutrino Masses and the Quest for Unification K.S. Babu Oklahoma State University Physics Seminar Wichita State University, Wichita, KS November 6, 2013

2. Cosmic Gall Neutrinos, they are very small. They have no charge and have no mass And do not interact at all. The earth is just a silly ball To them, through which they simply pass, Like dustmaids down a drafty hall Or photons through a sheet of glass. They snub the most exquisite gas, Ignore the most substantial wall, Cold-shoulder steel and sounding brass, Insult the stallion in his stall. And, scorning barriers of class, Infiltrate you and me! Like tall And painless guillotines, they fall Down through our heads into the grass. At night, they enter at Nepal And pierce the lover and his lass From underneath the bed—you call It wonderful; I call it crass. John Updike Telephone Poles and Other Poems, 1963

5. A Brief History of Neutrinos • Postulated by Pauli as a desperate measure to restore momentum and energy conservation in beta decay (1930) • Electron type neutrino discovered by Reines and Cowan in reactor experiments (1956) -- Nobel Prize in 1995 • Muon type neutrino produced in accelerators by Lederman, Schwartz, Steinberger et al (1962) – Nobel Prize in 1988 • LEP experiments measure N(nu) = 2.994 +-0.012 (1991-2002) • Neutrinos from the Sun detected by Davis et al (1968) – Nobel Prize in 2002 • Neutrinos from Supernova 1987A detected in US and Japan -- Koshiba, Nobel Prize in 2002 • Neutrino oscillations discovered in atmospheric neutrinos [IMB, Kamiokonde Hints (1988), Discovery by SuperKamiokande (1998)] • Solar neutrino deficit confirmed by various experiments and interpreted as evidence for neutrino oscillations (1968 –) • Reactor antineutrino oscillations discovered – Daya Bay (2012), RENO, DoubleChooz, T2K

6. Neutrinos from the Sun

9. Neutrinos from the sky

11. L/E Dependence of atmospheric neutrinos

12. Daya Bay Reactor Neutrino Experiment

13. Global Fit to 3-Neutrino Oscilaltions

15. Minkowski (1977) Yanagida (1979) Gell-Mann, Ramond, Slansky (1979) Mohapatra, Senjanovic (1980)

16. Neutrino mixing versus quark mixing Leptons Quarks Disparity a challenge for Quark-Lepton unified theories.

17. Neutrino Masses Probe the Scale of Unification of all Forces

18. The Greatest Equations Ever?

19. Tied for 1st place:

20. Top Finishers

21. Quantum Mechanics & Relativity Dirac’s Equation (1927)

22. Antiparticles

23. Quantum Electrodynamics

24. Great Success of Quantum Electrodynamics e  m e m e e+e-→+-

26. - + - - + + R - + Test charge + - + - + -

27. - + - - + + - + R + - + - + -

30. g g g q g g

31. Causes charge screening

32. Causes color charge anti-screening

34. Asymptotic freedom Gross, Wilczek, Politzer Nobel Prize, 2004

38. e, , W±, Z0 e,  Symmetry Superstring Unification Energy 1019 GeV 1 GeV 102 GeV 1016 GeV uu d dd u

41. With SUSY, Quadratic Divergence Cancels

42. Spin = 0 Spin = 1/2 Spin = 0 Spin = 1/2 Spin = 1 Spin = 1/2

43. More Hints in favor of GUTs

46. Structure of Matter Multiplets SO(10) Standard Model

50. Baryon asymmetry of the universe