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 Benasque March 19,2015 Ettore Fiorini

Benasque March 19,2015 Ettore Fiorini

Double beta decays 1935 M.Goeppert-Mayer, P.R. 48 (1935) 512 T>1020 Majorana, Nuovo Cimento 14 (1937) 171 Symmetric Theory of Electron and Positron G. Racah, Nuovo Cimento 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 Benasque March 19,2015 Ettore Fiorini 3

(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 Benasque March 19,2015 Ettore Fiorini 4

Two neutrino and neutrinoless double beta decay Measurement of the CP phase in the 0n bb-decay Benasque March 19,2015 Ettore Fiorini 5

Benasque March 19,2015 Ettore Fiorini 6

How to search for bb decay Geochemical experiments 82Se = > 82Kr, 96Zr = > 96Mo, 128Te = > 128Xe , 130Te = > 130Te Radiochemical experiments 238U = > 238Pu (non confirmed) e- Direct experiments Source  detectors Source = detector Benasque March 19,2015 Ettore Fiorini 7

Many types of detectors 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 Benasque March 19,2015 Ettore Fiorini

A first source = detector bb experiment Benasque March 19,2015 Ettore Fiorini

RARE events One of the main problem => background Cosmic rays => underground physics Benasque March 19,2015 Ettore Fiorini 10

Where to go ? Benasque March 19,2015 Ettore Fiorini

Benasque March 19,2015 Ettore Fiorini

Benasque March 19,2015 Ettore Fiorini

The Jin Ping Laboratory (700 m.w.e) Benasque March 19,2015 Ettore Fiorini

Benasque March 19,2015 Ettore Fiorini

Radioactivity Ettore Fiorini Benasque March 19,2015

Benasque March 19,2015 Ettore Fiorini

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 Benasque March 19,2015 Ettore Fiorini

: Dirac or Majorana neutrino? → → <= => Majorana =>1937 RIGHT LEFT : → → <= => Majorana =>1937 Benasque March 19,2015 Ettore Fiorini

Benasque March 19,2015 Ettore Fiorini

EXO-200 => T2n1/2 2. 71±0. 017(stat. )±0. 06(sys. )×1021 yr 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 Benasque March 19,2015 Ettore Fiorini 21

Neutrino oscillations Sterile neutrinos LSND,Miniboon,Gallex,reactors Great discovery requires great evidence (P. de Bernardis) Benasque March 19,2015 Ettore Fiorini

Benasque March 19,2015 Ettore Fiorini

Benasque March 19,2015 Ettore Fiorini 24

Benasque March 19,2015 Ettore Fiorini

Bracking news then 0 in 76Ge <mn> ~ 0.34eV Benasque March 19,2015 Ettore Fiorini 26

GERDA Benasque March 19,2015 Ettore Fiorini

Complain by H.Klapdor Benasque March 19,2015 Ettore Fiorini

Future experiments on DBD Benasque March 19,2015 Ettore Fiorini 29

GERDA Majorana Supernemo Benasque March 19,2015 Ettore Fiorini

Benasque March 19,2015 Ettore Fiorini

Benasque March 19,2015 Ettore Fiorini

SNO+ Benasque March 19,2015 Ettore Fiorini

Benasque March 19,2015 Ettore Fiorini

NEXT Benasque March 19,2015 Ettore Fiorini

Energy resolution <1 eV ~ 1eV @ 6 keV Thermal detectors Thermal sensor absorber crystal Incident particle Energy resolution <1 eV ~ 1eV @ 6 keV ~10 eV ~keV @ 2 MeV Benasque March 19,2015 Ettore Fiorini

Benasque March 19,2015 Ettore Fiorini

CUORICINO CUORE0 CUORE Benasque March 19,2015 Ettore Fiorini

Heat+ scintillation , light, Cherenkov light Hybrid techniques Heat+ scintillation , light, Cherenkov light Benasque March 19,2015 Ettore Fiorini 39

0νββ emitters: 130Te, 82Se, 100Mo & few others Crystals: TeO2 , ZnSe, ZnMoO4, CaMoO4 Operation at <20 mK: Heat sink Thermometer Crystal made from ββ-isotopes Cuore (w/o light detection) Lucifer, Lumineu, Amore (with light detection) Light detector Lucifer Benasque March 19,2015 Ettore Fiorini

9/15 kg 82Se delivered final batch for 02/2015 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’ Benasque March 19,2015 Ettore Fiorini

Now a competitor AMORE Advanced Mo based Rare process Experiment Benasque March 19,2015 Ettore Fiorini

The nightmare of matrix elements Francesco Jachello entering the field Before the nightmare Francesco Jachello entering the field Benasque March 19,2015 Ettore Fiorini

Robertson idea Benasque March 19,2015 Ettore Fiorini 44

Benasque March 19,2015 Ettore Fiorini

Is Francesco Iachello right ? Amicus Plato, sed magis amica veritas Plato is a friend , but truth even a better one Benasque March 19,2015 Ettore Fiorini

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 Benasque March 19,2015 Ettore Fiorini

The Fukushima accident. Agreement by bb groups =>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 Radionuclide Origin Gamma Peak (keV) Branching ratios (%) Absolute detection efficiency εabs (%) Min (μ Bqm−3) Max (μ Bqm−3) Mean (μ Bqm−3) 7Be Cosmogenic 477 10.3 0.69 ± 0.10 200 ± 40 970 ± 190 470 ± 90 131I Fukushima 284 81.2 1.08 ± 0.16 23 ± 4 410 ± 82 82 ± 16 364 60.6 0.88 ± 0.13 134Cs 604 97.6 0.57 ± 0.09 1.3 ± 0.3 80 ± 16 9.2 ± 1.8 796 85.4 0.47 ± 0.07 136Cs 818 100 0.46 ± 0.07 0.005 ± 0.001 137Cs 661 84.6 0.54 ± 0.08 1.6 ± 0.3 93 ± 19 10 ± 2 Benasque March 19,2015 Ettore Fiorini

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? Benasque March 19,2015 Ettore Fiorini

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 Benasque March 19,2015 Ettore Fiorini

There are more things in Earth and Heaven , Polonius, that can be dreamt of by your Philosophy Hamlet Benasque March 19,2015 Ettore Fiorini