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Double beta decay, neutrino physics and something else

Double beta decay, neutrino physics and something else. The birth of double beta decay From low energy nuclear physics to neutrino mass and properties The physics of rare events Experimental approaches and difficulties Present experimental status The future

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Double beta decay, neutrino physics and something else

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  1. Double beta decay, neutrino physics and something else • The birth of double beta decay • From low energy nuclear physics to neutrino mass and properties • The physics of rare events • Experimental approaches and difficulties • Present experimental status • The future • The nightmare of nuclear matrix elements • Something else • Conclusions Ettore Fiorini

  2. Ettore Fiorini

  3. Double beta decays • 1935 M.Goeppert-Mayer, P.R. 48 (1935) 512 T>1020 • Majorana, NuovoCimento 14 (1937) 171 • Symmetric Theory of Electron and Positron • G. Racah, NuovoCimento 14 (1937) 322 • W.H. Furry Lepton number nonconservation • 1967: 130Te, Geochemical Ogata and Takaoka, • Kirsten et • 1987: 82Se, Direct counting Moe et al • . • 1987 : Source=detector 48Ca, 76Ge Ettore Fiorini 3

  4. (A,Z) => (A,Z+2) + 2 e- + 2 ne • Two neutrino double beta decay Allowed by the standard model • Found in eleven nuclei ( 130Xe is new!) to ground state and in two to excited state • (A,Z) => (A,Z+2) + 2 e- + c ( …2,3 c) Emission of a massless Goldston boson named Majoron (Gelmini and Roncadelli) • 3. (A,Z) => (A,Z+2) + 2 e- • Neutrinoless double beta decay. The two electrons share the total transition energy E1 + E2 => DE => a peak should appear in the sum spectrum of the two electrons Other possible “DL=2” decays- Double positron decay => b+ b+- Positron decay + Electron Capture => EC- b+ - Double electron capture => EC-EC Ettore Fiorini 4

  5. Two neutrino and neutrinoless double beta decay Measurement of the CP phase in the 0n bb-decay Ettore Fiorini 5

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  7. e- e- How to search for bb decay Geochemical experiments82Se = > 82Kr, 96Zr = > 96Mo, 128Te = > 128Xe , 130Te = > 130TeRadiochemical experiments238U = > 238Pu (non confirmed) Direct experiments Source  detectors Source = detector Ettore Fiorini 7

  8. Experimental challenges Many types of detectors • Cloud chambers • Emulsions? • Bubble chambers ? (yes for Dark Matter) • Scintillators • Double state liquids • Time projectrion chambers • Tracking and imagining devices • Single atom counters 136Xe => 136Ba • Bolometers • Hybrid devices Ettore Fiorini

  9. A first source = detector bb experiment Ettore Fiorini

  10. RARE events One of the main problem => background Cosmic rays => underground physics 10 Ettore Fiorini

  11. Where to go ? Ettore Fiorini

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  14. The Jin Ping Laboratory (700 m.w.e) Ettore Fiorini

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  16. Radioactivity Ettore Fiorini

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  18. The second mystery of Ettore Majorana ne ne In 1937, Majorana [2] theoretically showed that the conclusions of the theory of β decay remain unchanged under the assumption of the existence of only one type of the neutrino having no antiparticle Ettore Fiorini

  19. Dirac or Majorana neutrino? : RIGHT : LEFT → → <==> Majorana =>1937 Ettore Fiorini

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  21. EXO-200 => T2n1/2 2.71±0.017(stat.)±0.06(sys.)×1021 yr.Kamland-Zen 2.38 ± 0.02(stat) ± 0.14(syst) × 1021 yr GERDA I 1.84 +0.14 -10(stat) × 1021 yr Ettore Fiorini 21

  22. Neutrino oscillations Sterile neutrinos LSND,Miniboon,Gallex,reactors Great discovery requires great evidence (P. de Bernardis) Ettore Fiorini

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  26. Bracking news then 0 in 76Ge <mn> ~ 0.34eV Ettore Fiorini 26

  27. GERDA Ettore Fiorini

  28. Complain by H.Klapdor Ettore Fiorini

  29. Future experiments on DBD Ettore Fiorini 29

  30. GERDA Majorana Supernemo Ettore Fiorini

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  33. SNO+ Ettore Fiorini

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  35. NEXT Ettore Fiorini

  36. Thermal sensor absorber crystal Incident particle Thermal detectors Energy resolution <1 eV~ 1eV @ 6 keV ~10 eV~keV@ 2 MeV Ettore Fiorini

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  38. CUORICINO CUORE0 CUORE Ettore Fiorini

  39. Hybrid techniques Heat+ scintillation , light, Cherenkov light Ettore Fiorini 39

  40. 0νββ emitters: 130Te, 82Se, 100Mo & few others Crystals: TeO2 , ZnSe, ZnMoO4, CaMoO4 Operation at <20 mK: Thermometer Heat sink Crystal made from ββ-isotopes Cuore (w/o light detection) Lucifer, Lumineu, Amore (with light detection) Light detector Lucifer Ettore Fiorini

  41. Qββ (82Se) = 2995 keV Array of 32-36 enr. (95%) Zn82Se crystals Total 82Se nuclei: (6.7-8.0) 1025 Single detector: 460 g BI (goal): 1-2 x10-3 cts / (keV kg yr) ΔE (FWHM): 10-15 keV • Bgd (internal α’s): • 17.2±4.6 μBq/kg (232Th) • 24.6±5.5 μBq/kg (238U) • Isotope delivery: • 9/15 kg 82Se delivered final batch for 02/2015 • Crystal growth: • Schedule for Jan - June 2015 • Current yield: 70% ‘anomalous β/γ-quenching’ Ettore Fiorini

  42. Now a competitor AMOREAdvanced Mo based Rare process Experiment Ettore Fiorini

  43. The nightmare of matrix elements Before the nightmare Francesco Jachello entering the field Ettore Fiorini

  44. Robertson idea Ettore Fiorini 44

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  46. Is Francesco Iachello right ? Amicus Plato, sed magis amica veritas Plato is a friend , but truth even a better one Ettore Fiorini

  47. Majorana neutrino and consequences Detectors of unprecedentent sensitivity • Environmental radioactivity • Trace elements • Archaeometry Reactors => friends and enemies Is neutrinoless double beta decay the only way to test lepton conservation? A possible experiment to search ne => n A favor to be returned => reactor physics => Measurement of the position of the fire inside the reactor => Displacement of the Uranium column in the core Ettore Fiorini

  48. The Fukushima accident. Agreement by bbgroups =>Measurements of air contamination in Osaka, Berkeley, Seattle etc. Only partially related to the distance Detection of air contamination a factor of million less in Milan with respect to Fukushima Ettore Fiorini

  49. Majorana theory for electron and positron Application to neutrino=> can a ½ spin particle be its own antiparticle? In superconductors Cooper pairs, being boson like particles, form condensates. Cooper pairs can be added to semiconductors with hole producing spin ½ exitons. Superconductors can contain magnetic wires acting as quasiparticles Can the Majorana rule be applied to these quasiparticles? Ettore Fiorini

  50. Conclusions Massive detectors (now expensive) of unique sophistication The reduction of the background which could hide neutrinoless bb events has reached an unprecedented sensistivity The quenching due to the new value assummed for gA could reduce the expecttion of the neutrino mass limit by a factor 4 to 5. If true it strongly reduces our hope to reach the invers hierarchy region The validity to extend to neutrinoles DBD the gA obtained from two neutrino and single beta decay should be justified The sophistication reached and to be reached in serches for DBD could have appplications in other fields of science Aplication to solid state physics of the Maiorana theory could bring to results as important as in elementary particle physics Ettore Fiorini

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