Presentation on theme: "Claudia Nones Physics of Massive Neutrinos - Blaubeuren, July 1 - 5, 2007 Status of Cuoricino and CUORE with some remarks on nuclear matrix elements Centre."— Presentation transcript:
Claudia Nones Physics of Massive Neutrinos - Blaubeuren, July 1 - 5, 2007 Status of Cuoricino and CUORE with some remarks on nuclear matrix elements Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse - Orsay
Brief remarks on the bolometric technique and the choice of 130 Te as source of the 0vDBD Cuoricino experiment: the detector and the updated results CUORE project Outline of the talk Cuoricino vs HM ; 130 Te vs other isotopes: comparisons through different N.M.E. calculations seen by the eyes of an experimentalist Conclusions
deposited energy heat sink thermal coupling absorber crystal temperature sensor Bolometric technique: Main advantages: - high energy resolution - wide flexibility (few constraints on absorber material) - the detector is fully sensitive (no dead layer) (also a drawback) From a very simple thermal model -> to develop high pulses the detector has to work at low temperature (10mk) Signal:∆T = E/C Brief remarks WHY 130 Te ? high natural isotopic abundance (33.87 %) high transition energy (Q=2530.30 ± 1.99 keV) - this means large phase space for the decay - the Q-value is important with respect to the natural radioactive background encouraging theoretical calculations for 0vDBD lifetime
Cuoricino and CUORE Location Cuoricino experiment is installed in Underground National Laboratory of Gran Sasso L'Aquila – ITALY the mountain providing a 3500 m.w.e. shield against cosmic rays R&D final tests for CUORE (hall C) CUORE (hall A) Cuoricino (hall A)
It is a self-consistent experiment giving significant results on Double Beta Decay. The Cuoricino detector Total number of detectors: 62 total active mass TeO 2 : 40.7 kg 130 Te : 11.3 kg 128 Te : 10.5 kg
Neutrinoless DBD results (1) Background sum spectrum of all the detectors in the DBD region 60 Co pile up Energy (keV) Counts 130 Te 0vBB MT = 11.83 kg 130 Te y
UPDATED RESULTS: T 1/2 0v (y) > 3 10 24 y m ee < 0.2 – 0.98 eV Bkg = 0.18±0.02 c/keV/kg/y Neutrinoless DBD results (2) Are we now able to scrutinize the HM claim of evidence? … we will see in the last part of the talk!!! MT = 11.83 kg 130 Te y FWHM measured on sum bkg spectrum @ 2.6 MeV ~ 7 keV
Cryogenic Underground Observatory for Rare Events CUORE
CUORE status Funded by the US For the moment, we are not late with respect to the master plan Data taking foreseen in 2011
“PER ME SI VA NE LA CITTA’ DOLENTE, PER ME SI VA NE L’ETERNO DOLORE, PER ME SI VA TRA LA PERDUTA GENTE. GIUSTIZIA MOSSE IL MIO ALTO FATTORE: FECEMI LA DIVINA POTESTATE, LA SOMMA SAPIENZA E ‘L PRIMO AMORE. DINANZI A ME NON FUR COSE CREATE SE NON ETERNE, E IO ETERNA DURO. LASCIATE OGNI SPERANZA, VOI CH’ENTRATE.” (Inferno, Canto III, vv. 1-9) « THROUGH ME THE WAY TO THE CITY OF WOE, THROUGH ME THE WAY INTO ETERNAL PAIN, THROUGH ME THE WAY AMONG THE LOST. JUSTICE MOVED MY MAKER ON HIGH. DIVINE POWER MADE ME, WISDOM SUPREME, AND PRIMAL LOVE. BEFORE ME NOTHING WAS BUT THINGS ETERNAL,AND I ENDURE ETERNALLY. ABANDON ALL HOPE, YOU WHO ENTER HERE. » The world of the Nuclear Matrix Elements through the eyes of an experimentalist Thanks to A. Poves, V. Rodin and J. Suhonen for their help…in this hell!!!
QRPA or not QRPA?…this is the question!!! QRPA Shell Model J. Suhonen – O. Civitarese and the Jyväskylä group A. Faessler and the Tuebingen group Prof. Faessler’s advice: « Do not take democratic averaged matrix elements » … but so what can we do with our value of T 0v 1/2 ? to evaluate m v to scrutinize the HM result to compare next generation experiments E. Caurier, F. Nowacki, A. Poves, et al.
Cuoricino prospects Are we able now to scrutinize the HM claim of evidence? T 1/2 0v (y) = (0.69-4.18) 10 25 (3σ range) m ee = 0.24 – 0.58 eV (3σ range) HM experimental results: REF. Klapdor et al., Physics Letters B 586 (2004) 198-212 Best value: 1.19x10 25 y What I have done… T 1/2 0v (Klapdor) T 1/2 0v ( 130 Te) Choose a nuclear model Nuclear matrix element of Muto-Bender-Klapdor References Tuebingen’s group: erratum of nucl-th/0503063 Suhonen’s group: nucl-th/0208005 Shell Model: Poves’ talk @ 4th ILIAS Annual Meeting - Chambery
T 1/2 x 10 24 y for 130 Te Nuclear models Jyväskylä group Shell model group Tuebingen group N.B.: No univoque definition of G 0v and M 0v !!! Cuoricino limit vs Klapdor’s claim of evidence 3x10 24 y 6x10 24 y Final sensitivity
The main goal of CUORE is to test the inverted hierarchy And what about CUORE? (1)
a: isotopic abundance A: atomic mass ε: efficiency M: active mass [kg] T: live time [y] b: background [c/keV/kg/y] Γ: energy resolution [keV] CUORE_conservative b=0.01 – Γ=5 – T=5y CUORE_aggressive b=0.001 – Γ=5 – T=5y F 0v = 2.1 x 10 26 y (1σ) F 0v = 6.6 x 10 26 y (1σ) And what about CUORE? (2)
CUORE and the inverted hierarchy T 1/2 x 10 26 y for 130 Te Nuclear models CUORE_conservative CUORE_aggressive Tuebingen group Shell Model group Jyväskylä group
Summarizing Tuebingen group Shell Model group Jyväskylä group Cuoricino CUORE_conservative CUORE_aggressive T 1/2 x 10 24 y for 130 Te
IsotopeQ_value (keV) Isotopic abundance (%) 48 Ca42710.0035 76 Ge20399.2 82 Se29959.2 100 Mo30349.6 116 Cd28027.5 130 Te253033.8 136 Xe24798.9 What about 130 Te compared with other isotopes? a)I fix the range of the mass -> inverted hierarchy (19-50 meV) b)I use the 3 main “schools of thoughts” in terms of N.M.E. c)I compare the capability to explore the inverted hierarchy region References Tuebingen’s group: erratum of nucl-th/0503063 Suhonen’s group: nucl-th/0208005 Shell Model: Poves’ talk @ 4th ILIAS Annual Meeting - Chambery
RQRPA (erratum) – Tuebingen group T 1/2 x 10 26 y 150 Nd 130 Te 116 Cd 76 Ge 136 Xe 82 Se 100 Mo G 0v calculates with g A =1.25 and r 0 =1.1fm
QRPA – Suhonen’s group G 0v calculates with g A =1.25 and r 0 =1.2fm T 1/2 x 10 26 y 130 Te 116 Cd 76 Ge 136 Xe 100 Mo 82 Se
Shell Model group G 0v calculates with g A =1.25 and r 0 =1.2fm T 1/2 x 10 26 y 130 Te 116 Cd 76 Ge 136 Xe 82 Se
Conclusions Cuoricino is presently the most sensitive 0νDBD running experiment, capable to confirm the KK-HM “evidence”. Cuoricino demonstrates the feasibility of a large scale bolometric detector (CUORE) with good energy resolution and bkg on many detectors. CUORE, a second generation detector, will be built and start up in the next 4 years. Recent results on background suppression confirm the capability to attack the inverted hierarchy mass region.
Isotope G 0v (g A =1.25 r 0 =1.2fm) G 0v (g A =1.25 r 0 =1.1fm) 76 Ge 6.31x10 -15 7.92x10 -15 82 Se 2.73x10 -14 3.52x10 -14 100 Mo 4.42x10 -14 5.73x10 -14 116 Cd 4.68x10 -14 6.22x10 -14 130 Te 4.14x10 -14 5.54x10 -14 136 Xe 4.37x10 -14 5.91x10 -14 150 Nd 1.94x10 -13 2.70x10 -13 There is a difference of about 25% Unit:y Suhonen + SMRodin