Double beta decay, neutrino and Majorana theory
1.The birth of double beta decay 2. From low energy nuclear physic to neutrino mass and properties 3. Experimental approaches and difficulties 4. Present experimental status 5. The nightmare of nuclear matrix elements 6. The future 7. News on Nuclear Matrix Elements 8. Majorana theory in solid states 10.Conclusions
Ettore Fiorini Brussel May 29 2015 1 Ettore Fiorini Brussel May 29 2015 2 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
Ettore Fiorini Brussel May 29 2015 3
- 1. (A,Z) => (A,Z+2) + 2 e + 2 ne Two neutrino double beta decay Allowed by the standard model Found in eleven nuclei to ground state and in two to excited state
2. (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 Brussel May 29 2015 4 Two neutrino and neutrinoless double beta decay
Measurement of the CP phase in the 0n bb-decay Ettore Fiorini Brussel May 29 2015 5 Experimental challenges Many types of detectors • Cloud chambers • Emulsions? • Bubble chambers (yes for Dark Matter) • Scintillators • Double state liquids • Time projectrion chambers • Imagining devices • Single atom counters 136Xe => 136Ba • Bolometers • Hybrid devices
Ettore Fiorini Brussel May 29 2015 6 How to search for bb decay
Geochemical experiments 82Se = > 82Kr, 96Zr = > 96Mo, 128Te = > 128Xe , 130Te = > 130Te Radiochemical experiments 238U = > 238Pu (non confirmed)
Direct experiments
Source = detector Source detectors
e-
e-
Ettore Fiorini Brussel May 29 2015 7 Thermal detectors Q DT Thermal sensor CV
v T 3 C V 1944 ( ) J/K vm absorber crystal
Incident particle
Energy resolution <1 eV ~ 1eV @ 6 keV ~10 eV ~keV @ 2 MeV
Ettore Fiorini Brussel May 29 2015 8 A first bb experiment
Ettore Fiorini Brussel May 29 2015 9 RARE events
One of the main problem => background
Cosmic rays => underground physics
Ettore Fiorini Brussel May 29 2015 10 Ettore Fiorini Brussel May 29 2015 11 The Jin Ping Laboratory (700 m.w.e) INO
Ettore Fiorini Brussel May 29 2015 12 Ettore Fiorini Brussel May 29 2015 13 Radioactivity
Ettore Fiorini Brussel May 29 2015 14 CUORICINO
Ettore Fiorini Brussel May 29 2015 15 The second mystery of Ettore Majorana
In 1937, Majorana theoretically showed that the conclusions of the theory of β decay remain unchanged under the assumption of the existence of only onetype of the neutrino having no antiparticle (i.e., ν ≡ ¯ ν).
Ettore Fiorini Brussel May 29 2015 16 Dirac or Majorana neutrino?
n: LEFT
RIGHT n:
→ → Majorana <= => =>1937
Ettore Fiorini Brussel May 29 2015 17 Ettore Fiorini Brussel May 29 2015 18 Neutrino oscillations
Sterile neutrinos LSND,Miniboon,Gallex,reactors)
Ettore Fiorini Brussel May 29 2015 19 Ettore Fiorini Brussel May 29 2015 20 Ettore Fiorini Brussel May 29 2015 21 Bracking news => 0nbb in 76Ge
Ettore Fiorini Brussel May 29 2015 22 Present results on neutrinoess DBD
Ettore Fiorini Brussel May 29 2015 23 BUT => GERDA
Ettore Fiorini Brussel May 29 2015 24 Future experiments on DBD
Ettore Fiorini Brussel May 29 2015 25 GERDA Majorana Supernemo
Ettore Fiorini Brussel May 29 2015 26 Brussel May 29 2015 27 Ettore Fiorini
Brussel May 29 2015 28 Ettore Fiorini Brussel May 29 2015 29 Ettore Fiorini Brussel May 29 2015 30 NEXT
Ettore Fiorini Brussel May 29 2015 31 CUORICINO CUORE0 CUORE
Ettore Fiorini Brussel May 29 2015 32 New
1/2 24 CUORE0 =>Ton > 2.7 x 10 90% c.l.
1/2 24 CUORE+CUORICINO =>Ton > 4 x 10 90% c.l. Ettore Fiorini Brussel May 29 2015 33 The future => Hybrid techniques
Ettore Fiorini Brussel May 29 2015 34 Now a competitor AMORE Advanced Mo based Rare process Experiment
Ettore Fiorini Brussel May 29 2015 35 The past
Brussel May 29 2015 36 Robertson
Brussel May 29 2015 37 Bracking news unpleasant F.Iachello => S.Dell’Oro and F.Vissani A.Faessler et al. J.Phys. G35 (2008) 075104
Quenching g A from 2n bb decay and one n b decay
Ettore Fiorini Brussel May 29 2015 38 The first strike by Brutus
39 The final strike by Brutus
- Impressive progress by cosmology on neutrino mass. - Recent data by Planck - A detailed analysis of cosmological results possibly favoring the direct hierarchy
(Palanque Delabrouille) Sm n < 0.17 eV or
Amicus Plato, sed magis amica veritas Platus is a friend.but truth even more
Ettore Fiorini Brussel May 29 2015 40
Majorana => can a ½ spin particle be its own antiparticle? So far application to neutrino Conventional Cooper excitons are bosons and not Majorana particles In superconductors Cooper pairs, being boson like particle, form condensates respecting Pauli principle How to produce excitons which are Majorana particles Cooper pairs can be added to holes producing spin ½ exitons. Superconductors can contain magnetic wires acting as quasiparticles Form magnetic flux tubes ( vortices)
Ettore Fiorini Brussel May 29 2015 41
Bi2Te 3 on a superconductor NbSe2 In normal superconductors Scanning with a tunneling microscope and sepctrocope one can find explicity a single Majorana mode. Common opinion: Majorana theory can be as impoortnt in solid state like it is In elementary particle physics
Brussel May 29 2015 42 Conclusions
Massive detectors (now expensive) of unique sophistication Reduction of background which could hide neutrinoless bb events has reached an unprecedented sensistivity
The quenching of gA reduces the matrix would ref+duce sensitivity oon neutrino mass limit by a factor 4 to 5. If so no present hope to reach the inverse hierarchy region
The validity to extend to neutrinoless 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 solid state physics
Ettore Fiorini Brussel May 29 2015 43 There are more things in Earth and Heaven , Polonius, that can be dreamt of by your Philosophy Hamlet
Ettore Fiorini Brussel May 29 2015 44