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Neutrino Masses, Leptogenesis and Beyond

The Incredible Foresight of ETTORE MAJORANA Haim Harari Erice, August 2006. Neutrino Masses, Leptogenesis and Beyond. b -Decay. e -. A 1  A 2 + e -. b -Decay. e -. e -. e -. e -. N 1  N 2 + e -. e -. e -. e -. e -. b -Decay. Missing Energy Missing Momentum.

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Neutrino Masses, Leptogenesis and Beyond

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  1. The Incredible Foresight of ETTORE MAJORANA Haim Harari Erice, August 2006 Neutrino Masses, Leptogenesis and Beyond

  2. b-Decay e- A1 A2 + e-

  3. b-Decay e- e- e- e- N1 N2 + e-

  4. e- e- e- e- b-Decay Missing Energy Missing Momentum N1 N2 + e-

  5. n e- e- e- e- b-Decay N1 N2 + e- +n “Dear Radioactive Ladies & Gentleman”

  6. b-Decay n e- e- e- e- n n p p e- n n  p + e- +n

  7. b-Decay n e- e- e- n e- n e- p n p n e- d d  u + e- +n

  8. 1016 n If 1016 n reach earth - one will hit something somewhere. With one thousand tons of water, and 1016n every second since the big bang - 1 EVENT !!! Pauli: “I have done a terrible thing!” The Elusive Neutrino No Electric ChargeNo Strong Interactions Spin = ½ Only Weak Interactions Small or Zero Mass

  9. Creating Nuclei n p + e- + n n + n e- + p p n + e+ + n n + p e+ + n (Can you tell n from n ?) The only way to convert a proton into a neutron or vice versa – involves the neutrino! Creation of stars Creation of heavy elements Energy of the sun Energy of stars Exploding stars: supernova

  10. 4p He4 + 2e+ + 2n + Energy Other Processes The SUN

  11. Reactor n n n + p e+ + n n + Z Z’ + g 1957 - Neutrino Observed e+ + e-2g Reines - Cowan Big Problem: DETECTING n Huge Problem: ELIMINATING BACKGROUND

  12. The Foresight Can you tell a neutrinofrom an anti-neutrino? MAJORANA n may be its own antiparticle !

  13. Is nMassless or Very Light? “Direct” experiments m (ne) < 10 eV Theory No good reason for massless n. Simple argument for very light n. n is only “chargeless” particle. All quarks and leptons  “Dirac Mass” n also “Majorana Mass”

  14. 0 m m L Is nMassless or Very Light? M1 ~ O(L) M2 ~ O(m2/L) “See-Saw” L m n Majorana Mass Gell-Mann, Ramond, Slansky, Yanagida

  15. Theorists predicted a new meson with a certain mass. A particle was found soon after, having the right mass. A second particle, very slightly heavier, was found soon after. The second particle turned out to be the predicted meson. The first particle turned out to be an unexplained heavy lepton,identical to the electron in all its properties, except its mass.

  16. Theorists predicted a new meson with a certain mass. A particle was found soon after, having the right mass. A second particle, very slightly heavier, was found soon after. The second particle turned out to be the predicted meson. The first particle turned out to be an unexplained heavy lepton,identical to the electron in all its properties, except its mass. p Yukawa ~100MeV ~100MeV Anderson-Neddermeyer Powell p m m (e) = 0.51 MeV m (m) = 106 MeV

  17. Theorists predicted a new meson with a certain mass. A particle was found soon after, having the right mass. A second particle, very slightly heavier, was found soon after. The second particle turned out to be the predicted meson. The first particle turned out to be an unexplained heavy lepton,identical to the electron in all its properties, except its mass. ~2000GeV GIM D ~1800MeV Perl SLAC-LBL D t m(e) = 0.51 MeV m(m) = 106 MeV m(t) = 1782 MeV

  18. p+m+ + n m Brookhaven 1962 p n n P Detector p p p p nmne The schizophrenic n One or Two Neutrinos Is the “partner” of m the same as the “usual” n, which comes with e ?

  19. meV meV eV keV MeV GeV TeV -6 -5 -4 -3 -2 -1 -0 1 2 3 4 5 6 7 8 9 10 11 12 Generation 1st Q u 2/3 d -1/3 Quarks ne? 0 e -1 Leptons ( ) u d ( ) ne e

  20. meV meV eV keV MeV GeV TeV -6 -5 -4 -3 -2 -1 -0 1 2 3 4 5 6 7 8 9 10 11 12 2nd Generation 1st Q c u 2/3 s d -1/3 Quarks ne? nm? 0 m e -1 Leptons ( ) ( ) u d c s 1970 GIM: “CHARM” ( ) ( ) ne e nm m

  21. meV meV eV keV MeV GeV TeV -6 -5 -4 -3 -2 -1 -0 1 2 3 4 5 6 7 8 9 10 11 12 2nd 3rd Generation 1st Q c u t 2/3 s d b -1/3 Quarks ne? nm? nt? 0 m t e -1 Leptons ( ) ( ) ( ) u d c s t b “The Standard Model” ( ) ( ) ( ) ne e nm m nt t

  22. u d c s ( ) ( ) ( ) t b Mixing Angles (small) “Mass Eigenstates” “Weak Eigenstates” Mixing Cabibbo

  23. 0 m m L Is nMassless or Very Light? M1 ~ O(L) M2 ~ O(m2/L) “See-Saw” L m n Majorana Mass Gell-Mann, Ramond, Slansky, Yanagida

  24. Planck GUT L PeV TeV S.M. t b c m s u d e GeV MeV keV eV meV meV neV 30 27 24 21 18 15 12 9 6 3 0 -3 nt nm ne -6 -9 -12

  25. ne nm nt n1 n2 n3 Mass Eigenstates Generation Eigenstates L E Pij = Sin 2 2qij Sin 2 (1.27 Dm2ij) Km GeV · eV2 An Identity Crisis Reactor ne Accelerator nmSun ne n - Oscillations APPEARANCE DISAPPEARANCE

  26. L E Pij = Sin 2 2qij Sin 2 (1.27 Dm2ij) Km GeV · eV2 L E Dm2 << 1 P ~ 0 L E Dm2 >> 1 P= ½ Sin2 2ij L E Dm2 ~ O(1) probe Dm n - Oscillations e m 12 mt 23 e t 13 Three Mixing Angles

  27. If mj >> miDm2ij ~ mj2 Probe Dm2 E L Reactors: MeV m Accelerators: GeV km > > eV eV ~ ~ Hence: limits only on 12 All experiments were : Dm2 eV2 nenm nmne nenx nmnx 1000 Allowed Excluded 100 10 1 0.1 No nt Sin2 2q12 n - Oscillations

  28. Cosmic Background Radiation: 2.7°K 400 g 110 ne 110 nm 110 nt per cm3: Cosmological Dark Matter Closed Open flat The universe is 95% is Dark matter or Dark Energy What is the Dark Matter? If m(ne ) + m(nm ) + m(nt)~ O(few en) Dark matter would be n Hence: Crucial to search for nm - nt oscillations at O(eV)

  29. “CHORUS” CERN 1990 - 98 No events Cosmological Dark Matter t nm nt ~100m x Accelerator ntcannotaccount for most of the dark matter in the universe!

  30. Solar Neutrinos The sun emits 1038n per second. 1029 go to direction earth. Per 100 ton detector - 40 hits per month Homestake n + Cl37 e +A37 400 ton C2Cl4

  31. Kamiokande Super - Kamiokande Kamiokande n+ n e + p 50,000 ton/clean water

  32. GALLEX n + Ga71e +Ge71 30 ton

  33. GALLEX n + Ga71e +Ge71 30 ton SNO 1000 ton D2O (+2 ton Salt) 10,000 phototubes ne + d e + p + p (charged Current) nx + dnx + p + n (Neutral Current) nx + e nx +e (Elastic Scattering) Count total n – flux and ne - flux

  34. Solar Model is Right! Neutrinos Oscillate Neutrinos have Mass m(nm) ~ 8 meV q12Large

  35. Kamland – Japan R R KAM R R L ~ 180 km E ~ O (MeV) Probe: ∆m2<<eV2

  36. KAMIOKANDE: N(nm) N(ne) = 1.2 !!! m(nt) ~ 50 meV Cosmic Radiation Energetic protons arrive p Pions created in atmosphere In p-decay: N(nm) N(ne) atmosphere p = 2 m e ne nm nm earth

  37. The Universe 70% Dark Energy 25% Dark Matter 4% H, He 0.5% Heavy Nuclei 0.5% Neutrinos m(nt) ~ 50 meV m(nm) ~ 8 meV m(ne) ~ smaller Large angles! Also K2K, MINOS,others

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