The importance of being Neutrino The birth of the neutrino Ettore Fiorini, Varenna June 17, 2008 1
Named Neutrino by Enrico Fermi => first properties of weak interactrions ν e G F (Fermi constant) n p Ettore Fiorini, Varenna June 17, 2008 2
More than 70 years of searches => parity violation, three flavours, lepton and flavor conservation (???) Charged currents Neutral currents Ettore Fiorini, Varenna June 17, 2008 3
Neutrino oscillations Ettore Fiorini, Varenna June 17, 2008 4
Solar neutrinos ( νe) Ettore Fiorini, Varenna June 17, 2008 5
Spectrum of solar neutrinos Ettore Fiorini, Varenna June 17, 2008 6
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SNO and the New SNOLAB Ettore Fiorini, Varenna June 17, 2008 8
Geo-Neutrinos can we detect the antineutrinos produced by natural radioactivity in the Earth? radioactive decay of heavy elements (Uranium, Thorium) produces antineutrinos e Ettore Fiorini, Varenna June 17, 2008 9
Atmospheric neutrinos Super- Kamiokande ν e ~ as predicted ν µ deficit from below Ettore Fiorini, Varenna June 17, 2008 10
Reactor Neutrinos 2002: Ettore Fiorini, Varenna June 17, 2008 11
Reactors (the future) Double-CHOOZ (France) σιν 2 θ13 < 0.022 280 m 1051 m σιν 2 2θ13 0.03 Daya Bay (China) DOUBLE CHOOZ Ettore Fiorini, Varenna June 17, 2008 12
Accelerators Minos K2K Simulated tau event: Ettore Fiorini, Varenna June 17, 2008 13
Two different hierarchy models Ettore Fiorini, Varenna June 17, 2008 14
CMB Anisotropy µk nk WMAP Ettore Fiorini, Varenna June 17, BOOMERanG 2008 DASI 15
<m ν > from Cosmology mν = 0 ev mν = 1 ev mν = 7 ev mν = 4 ev Ettore Fiorini, Varenna June 17, 2008 16
Measurement (or limit ) on neutrino mass by single beta decay Tiny effect -> Ettore Fiorini, Varenna June 17, 2008 17
m ν < 2.2 ev 3 H => 3 He + e - + ν e => KATRIN < 0.2 ev Katrin Ettore Fiorini, Varenna June 17, 2008 18
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The cryogenic or thermal detectors Ettore Fiorini, Varenna June 17, 2008 20
First ideas 1880 => Langley => resistive bolometers for infrrared from SUN 1905 => Curie et Laborde => calorimetric measurement of radioactivity 1927 => Ellis and Wuster => heat less then expected => the neutrino 1935 => Simon => sensitivity enhanced by lowering the temperature 1983 => T.Niinikoski =>observe pulses in resistors due to cosmic rays 1984 => McCammon et al (NASA-Wisconsin) Low temp. detectors for astrophysics and neutrino mass measurement => Fiorini and Niinikoski Low temperature detectors for rare events Ettore Fiorini, Varenna June 17, 2008 21
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!T = Q C V Thermal sensor C V = 1944 v v m ( T! ) 3 J/K absorber crystal Incident particle Excellent resolution <1 ev ~ 2eV @ 6 kev ~10 ev ~kev @ 2 MeV Ettore Fiorini, Varenna June 17, 2008 24
Non equilibrium and equilibrium detectors - - Various types of thermometers => a thermistor => a transition edge sensor (TES) => an Equilibrium Absorber weakly coupled to a heat bath superconducting tunnel junction (STJ) Cooper pair breaking => a magnetic thermometer. The temperature information is obtained from the change of a paramagnetic sensor placed in a small magnetic field Caveat => possibility that the heat capacity of the thermometer be comparable or larger than the absorber one: Ettore Fiorini, Varenna June 17, 2008 25
Non equilibrium detectors STJ Superconducting tunnel junctions SSG Superheated superconducting granules. The field does not enter more in the granule. Often SQUID pickup Suggested for In solar neutrino detection. Considered for Dark Matter Experiments => Superfluid 3 He and 4 He detectors (rotons). Also considered for Solar neutrinos Comparison with conventional detectors: => Slow propagation of the vibration inside the absorber Kapitza resistence detector => heat sink (slow rise and decay times) => Possible localizazion of the event (TES) Ettore Fiorini, Varenna June 17, 2008 26
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Macro and micro bolometers Ettore Fiorini, Varenna June 17, 2008 28
Energy resolution of a TeO 2 crystal of 5x5x5 cm 3 (~ 760 g ) 210 Po α line : 0.8 kev FWHM @ 46 kev 1.4 kev FWHM @ 0.351 MeV 2.1 kev FWHM @ 0.911 MeV 2.6 kev FWHM @ 2.615 MeV 3.2 kev FWHM @ 5.407 MeV (the best α spectrometer so far Ettore Fiorini, Varenna June 17, 2008 Energy [kev] 29
Orpheus 0.45 kg of granules 70 m.w.e for Dark Matter detection Bern Considered also for double beta decay (A.Morales) Ettore Fiorini, Varenna June 17, 2008 30
Hybrid techniques heat + ionization or heat + scintillation SQUID array Phonon D R bias R feedback I bias D C A B Q outer Q inner V qbias Ettore Fiorini, Varenna June 17, 2008 31
The scintillating bolometer Proved for CaF 2 being studied for TeO 2 Ettore Fiorini, Varenna June 17, 2008 32
Microcalorimeters for 187 Re ß-decay MIBETA: Kurie plot of 6.2 106 Re ß-decay events (E > 700 ev) MANU2 (Genoa) metallic Rhenium m ν < 26 ev Nucl. Phys. B (Proc.Suppl.) 91 (2001) 293 10 crystals: 8751 hours x mg (AgReO4) MIBETA (Milano) AgReO4 m ν < 15 ev Nucl. Instr. Meth. 125 (2004) 125 m 2 ν E 0 = (2465.3 ± 0.5stat ± 1.6syst) ev = (-112 ± 207 ± 90) ev2 Ettore Fiorini, Varenna June 17, 2008 MARE (Milano, Como, Genoa, Trento, US, D) Phase I : m ν < 2.5 ev hep-ex/0509038 33
A new fact in Material Science and Nuclear Physics => Beta Environmenthal Fine Structure 187 Re => 187 Os + e - + ν e ΔE = 2.5 kev The Genoa spectrum with metallic Rhenium Ettore Fiorini, Varenna June 17, 2008 34
The structure of BEFS has allowed to determine the P to S ratio of the beta decay Ettore Fiorini, Varenna June 17, 2008 35
Other interesting results in nuclear physics obtatined with cryogenic detctors e - + 163 Ho => 163 Os + ν e also for searches on neutrino mass 113 Cd => 113 I + e - + ν e τ 1/2 = (9+1) x 10 15 y e - + 123 Te => 123 Sb + ν e τ 1/2 > 10 15 y e - + 7 Be => 7 Li + ν e e - + Ga => 71 Ge + ν e => for solar neutrinos => for solar neutrinos First discovery of the decay 209 Bi => 204 Tl + α Experiments with heavy ions Ettore Fiorini, Varenna June 17, 2008 36
Problems of cryogenic detectors: The are slow and totally sensitive surface contamination Ettore Fiorini, Varenna June 17, 2008 37
What about the nature of the neutrino and its mass? Ettore Fiorini, Varenna June 17, 2008 38
Neutrinoless double beta decay and Majorana neutrinos ν: LEFT ν: RIGHT <= => Majorana =>1937 Ettore Fiorini, Varenna June 17, 2008 39
1. (A,Z) => (A,Z+2) + 2 e - + 2 ν e 2. (A,Z) => (A,Z+2) + 2 e - + χ ( 2,3 χ) 3. (A,Z) => (A,Z+2) + 2 e - Ettore Fiorini, Varenna June 17, 2008
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Double Beta Disintegration M.Goeppert-Mayer, The John Hopkins University (Received May, 20, 1935) From the Fermi theory of β- disintegration the probability of simultameous emission of two electrons (and two neutrinos) has been calculated. The result is that this process occurs sufficiently rarely to allow an half-life of over 10 17 years for a nucleus, even if its isobar of atomic number different by 2 were more stable by 20 times the electron mass At the beginning neutrinoless ββ decay searched as the most powerful method to test conservation of lepton number. Today, after discovery of neutrino oscillations represents the best way to measure <mν> Ettore Fiorini, Varenna June 17, 2008 42
d d u e - W ν e W ν e e - u 2ν - ββ decay d d W W u ν e u ν e 0ν - ββ decay e - e - Neutrinoless ββ decay Ettore Fiorini, Varenna June 17, 2008 43
Predictions from neutrino oscillations Ettore Fiorini, Varenna June 17, 2008 44
Experimental approach Geochemical experiments 82 Se = > 82 Kr, 96 Zr = > 96 Mo, 128 Te = > 128 Xe (non confirmed), 130 Te = > 130 Xe Radiochemical experiments 238 U = > 238 Pu (non confirmed) Source = detector (calorimetric) Direct ex-periments Source detector e - e - Ettore Fiorini, Varenna June 17, 2008 45
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The rate of neutrinoless DBD rate of DDB-0ν Phase space Nuclear matrix elements EffectiveMajorana neutrino mass 1/τ = G(Q,Z) Mnucl 2 <mν> 2 Nucleus T 0n (y) 1 2 3 5 6 Faessler (Erratum) 48 Ca >1.4x10 22 22 76 Ge >1.9x10 25.47.55.41.97.84.36 ±.07 76 Ge >1.6x10 25.51.60.44 1.1.91.40±.08 76 Ge 1.2x10 25.59.69.52 1.2 1.1.46±.09 82 Se >2.1.x10 23 2.2 2.9 1.8 2.8 3.7 1.9±2.0 100 Mo >5.8x10 23.97 2.7 1.1 11 1.1 ±.3 116 Cd >1.7x10 23 2.4 3.5 1.4 2.7 2.3±.8 128 Te >7.7 10 24 1.8 2.5 4.6 2.0 1.5±.6 130 Te >3x10 24.7.85.37 1.1 1.8.48±.15 136 Xe >1.2x10 24 2.9 2.0.42 2.6 1.2±.5 150 Nd >1.2x10 21 2.7 4.4 1.0.84 8±4 49
Claim of Evidence for 0νββ in 76 Ge <m> ~ 0.2 to 0.3 ev Single-site events in detectors 2, 3, 4, 5 (56.6 kg-y). H.V. Klapdor-Kleingrothaus, Int. J. Mod. Phys. E17, 505 (2008) Looks good to me not to me (E.F.) Ettore Fiorini, Varenna June 17, 2008 50
Two new experiments NEMO III e CUORICINO Ettore Fiorini, Varenna June 17, 2008 51
Searches with thermal detectors CUORE R&D (Hall C) CUORE (Hall A) Cuoricino (Hall A) Ettore Fiorini, Varenna June 17, 2008 52
Mass increase of bolometers total mass [kg] year Ettore Fiorini, Varenna June 17, 2008 53
Detectors assembling Operations carried out In a clean room Ettore Fiorini, Varenna June 17, 2008 54
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Search for the 2β oν in 130 Te (Q=2529 kev) and other rare events At Hall A in the Laboratori Nazionali del Gran Sasso (LNGS) 18 crystals 3x3x6 cm3 + 44 crystals 5x5x5 cm3 = 40.7 kg of TeO2 Operation started in the beginning of 2003 => ~ 4 months Background.18±.01 c /kev/ kg/ a T 0ν 1/2 ( 130 Te) > 3.1 x 10 24 y <m ν >.16 -.84 ev Klapdor 0.1 0.9 2 modules, 9 detector each, crystal dimension 3x3x6 cm 3 crystal mass 330 g 9 x 2 x 0.33 = 5.94 kg of TeO 2 Ettore Fiorini, Varenna June 17, 2008 11 modules, 4 detector each, crystal dimension 5x5x5 cm 3 crystal mass 790 g 4 x 11 x 0.79 = 34.76 kg of TeO 2 56
Present Cuoricino region Arnaboldi et al., submitted to PRL, hep-ex/0501034 (2005). Possible evidence (best value 0.39 ev) With the same matrix elements the Cuoricino limit is 0.53 ev quasi degeneracy m 1 m 2 m 3 Inverse hierarchy Δm 2 12 = Δm2 atm Ettore Fiorini, Varenna June 17, Feruglio F., Strumia A., Vissani F. hep-ph/0201291 2008 Direct hierarchy Δm 2 12 = Δ m 2 sol Cosmological disfavoured region (WMAP) 57
NEMO - SuperNEMO GERDA Experimental situation Experiment Nucleus Detector NEMO III 100 Mo et al 10 kg of enrich. Isotopes -tracking Cuoricino 130 Te + etc. 40 kg of TeO 2 bolometers (nat) CUORE 130 Te + etc. 750 kg of TeO 2 bolometers (nat) EXO 136 Xe 200kg - 1 t Xe TPC GERDA 76 Ge 30-40 kg - 1t Ge diodes in LN Majorana 76 Ge 180 kg - 1t Ge diodes MOON 100 Mo nat.mo sheets in plastic sc. DCBA 150 Nd 20 kg Nd -tracking CAMEO 116 Cd 1 t CdWO 4 in liquid scintillator COBRA 116 Cd, 130 Te 10 kg of CdTe semiconductors Candles 48 Ca Tons of CaF 2 in liquid scintillators GSO 116 Cd 2 t Gd 2 SiO 5 :Ce scintill.in liquid sc. Xe 136 Xe 1.56 Xenon in liquid scintillator. Xmass 136 Xe 1 t of liquid Xe CUORICINO MOON 2 P 1/2 493 nm 650 nm CUORE MOON SNO++ 2 S 1/2 4 D 3/2 metastable 47s EXO 58
CUORE expected sensitivity In 5 years: disfavoured by cosmology b (counts/kev/kg/y) 10-2 10-3 " [kev] 5 5 T 1/2 [y] 2.1 _ 10 26 6.5 _ 10 26 <m! > [mev] 19-100 11-57 Strumia A. and Vissani F. hep-ph/0503246 Ettore Fiorini, Varenna June 17, 2008 59
Other possible candidates for neutrinoless DBD Compound Isotopic abundance Transition energy 48 CaF 2.0187 % 4272keV 76 Ge 7.44 " 2038.7 " 100 MoPbO 4 9.63 " 3034 " 116 CdWO 4 7.49 " 2804 " 130 TeO 2 34 " 2528 " 150 NdF 3 5.64 " 3368 150 NdGaO 3 Ettore Fiorini, Varenna June 17, 2008 60
CONCLUSIONS Neutrino oscillations exist => Δm ν 2 0 Future experiments will enable to investigate in details the parameters of this process Determination of the absolute value of <m ν > becomes imperative Theory indicates <m ν > from a from few to a few tens of mev. The study of Cosmic Microwave Background determines the sum of neutrino masses with high precision. How much model dependent? Single beta decay constraints directly <m ν > but still far from predictions Future experiment on neutrinoless double beta decay could determine <m n > at the level predicted by neutrino oscillations under the inverse hierarchy hypothesis, and ascertain if neutrino is a Majorana particle The present claim for this phenomenon indicating <m ν > ~0.44 ev is not confirmed by CUORICINO The most advanced and sometime not yet tested nuclear physics techniques are being studied for future DBD experiment Determinaion of neutrino mass involves already nuclear and sub nuclear physics. Its peculiar multidisciplinarity involves fundamental problems in astroparticle physics, radioactivity, materials, geochronology ecc. Very stimulating for young people Ettore Fiorini, Varenna June 17, 2008
From the letter of Wolfang Pauli of December 1, 1930 From now on one should discuss seriously all side of the problem. Therefore, dear radioactive people, do investigate and judge. Unfortunately I cannot be personally in Tubingen since my presence is absolutely indispensable here for a ball that will take place here in the night between December 6 and 7. Your devoted servant Wolfang Pauli Ettore Fiorini, Varenna June 17, 2008 62