Download or read book Search for Neutrinoless Double Beta Decay of Te130 with CUORE 0 written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the results of a search for neutrinoless double-beta decay in a 9.8 kg yr exposure of 130Te using a bolometric detector array, CUORE-0. The characteristic detector energy resolution and background level in the region of interest are 5:1± 0:3 keV FWHM and 0:058 ± 0:004 (stat) ± 0:002 (syst) counts / (keV kg yr), respectively. The median 90% C.L. lower-limit half-life sensitivity of the experiment is 2:9x1024 yr and surpasses the sensitivity of previous searches. We find no evidence for neutrinoless double-beta decay of 130Te and place a Bayesian lower bound on the decay half-life, T0[nu]1/2> 2.7 x 1024 yr at 90% C.L. Combining CUORE-0 data with the 19.75 kg yr exposure of 130Te from the Cuoricino experiment we obtain T0[nu]1/2> 4.0 x 1024 yr at 90% C.L. (Bayesian), the most stringent limit to date on this half-life. Lastly, using a range of nuclear matrix element estimates we interpret this as a limit on the e ective Majorana neutrino mass, m[beta][beta]

Download or read book A Search for Neutrinoless Double Beta Decay of Te 130 written by Adam Douglas Bryant and published by . This book was released on 2010 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Search for Neutrinoless Double Beta Decay in Te With CUORE 0 written by Jonathan Loren Ouellet and published by . This book was released on 2015 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the design, operation and results of an experimental search for neutrinoless double beta decay (0$\nu\beta\beta$) of $^$Te using the CUORE-0 detector. The discovery of 0$\nu\beta\beta$ would have profound implications for particle physics and our understanding of the Universe. Its discovery would demonstrate the violation of lepton number and imply that neutrinos are Majorana fermions and therefore their own anti-particles. Combined with other experimental results, the discovery of 0$\nu\beta\beta$ could also have implications for understanding the absolute neutrino mass scale as well as the presently unknown neutrino mass hierarchy. The CUORE experiment is a ton-scale search for 0$\nu\beta\beta$ in $^$Te expected to begin operation in late 2015. The first stage of this experiment is a smaller 39-kg active-mass detector called CUORE-0. This detector contains 11~kg of $^$Te and operates in the Laboratori Nazionali del Gran Sasso lab in Italy from 2013 -- 2015. The results presented here are based on a $^\text{nat}$TeO$_2$ exposure of 35.2~kg$\cdot$yr, or 9.8~kg$\cdot$yr exposure of $^$Te collected between 2013 -- 2015. We see no evidence of 0$\nu\beta\beta$ and place an upper limit on the 0$\nu\beta\beta$ decay rate of $\Gamma_{0\nu\beta\beta}0.25\times10^{-24}$~yr$^{-1}$ (90\% C.L.), corresponding to a lower limit on the half-life of $T^{0\nu}_{1/2}2.8\times10^{24}$~yr (90\% C.L.). We combine the present result with the results of previous searches in $^$Te. Combining it with the 1.2~kg$\cdot$yr $^$Te exposure from the Three Towers Test run we place a half-life limit of $T_{1/2}^{0\nu}>3.3\times10^{24}$~yr (90\% C.L.). And combining these results with the 19.75~kg$\cdot$yr $^$Te exposure from CUORE-0ino, we place the strongest limit on the 0$\nu\beta\beta$ half-life of $^$Te to date, at $T^{0\nu}_{1/2}>4.5\times10^{24}$~yr (90\% C.L.). Using the present nuclear matrix element calculations for $^$Te, this result corresponds to a 90\% upper limit range on the effective Majorana mass of $m_{\beta\beta}

Download or read book Search for Neutrinoless Double Beta Decay of with CUORE 0 written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the results of a search for neutrinoless double-beta decay in a 9.8 kg yr exposure of 130Te using a bolometric detector array, CUORE-0. The characteristic detector energy resolution and background level in the region of interest are 5.1 ± 0.3 keV FWHM and 0.058 ± 0.004 (stat.) ± 0:002 (syst.) counts/(keV kg yr), respectively. The median 90% C.L. lower-limit sensitivity of the experiment is 2.9 x 1024 yr and surpasses the sensitivity of previous searches. We find no evidence for neutrinoless double-beta decay of 130Te and place a Bayesian lower bound on the decay half-life, T0$_1$1/2 > 2.7 x 1024 yr at 90% C.L. Combining CUORE-0 data with the 19.75 kg yr exposure of 130Te from the Cuoricino experiment we obtain T0$_1$1/2 > 4.0 x 1024 yr at 90% C.L. (Bayesian), the most stringent limit to date on this half-life. Using a range of nuclear matrix element estimates we interpret this as a limit on the effective Majorana neutrino mass, m??

Download or read book Searching for Neutrinoless Double Beta Decay of 130 Te with CUORE written by and published by . This book was released on 2015 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Searching for Neutrinoless Double Beta Decay of 130Te with CUORE written by and published by . This book was released on 2015 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neutrinoless Double beta Decay Search with CUORE and CUORE 0 Experiments written by and published by . This book was released on 2015 with total page 3004 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Cryogenic Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for the neutrinoless double-beta decays. Observation of the process would unambiguously establish that neutrinos are Majorana particles and provide information on their absolute mass scale hierarchy. CUORE is now under construction and will consist of an array of 988 TeO2 crystal bolometers operated at 10 mK, but the first tower (CUORE-0) is already taking data. The experimental techniques used will be presented as well as the preliminary CUORE-0 results. The current status of the full-mass experiment and its expected sensitivity will then be discussed.

Download or read book Analysis Techniques for the Evaluation of the Neutrinoless Double beta Decay Lifetime in 130Te with the CUORE 0 Detector written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, we describe in detail the methods used to obtain the lower bound on the lifetime of neutrinoless double-beta (0[nu][beta][beta]) decay in 130Te and the associated limit on the effective Majorana mass of the neutrino using the CUORE-0 detector. CUORE-0 is a bolometric detector array located at the Laboratori Nazionali del Gran Sasso that was designed to validate the background reduction techniques developed for CUORE, a next-generation experiment scheduled to come online in 2016. CUORE-0 is also a competitive 0[nu][beta][beta] decay search in its own right and functions as a platform to further develop the analysis tools and procedures to be used in CUORE. These include data collection, event selection and processing, as well as an evaluation of signal efficiency. In particular, we describe the amplitude evaluation, thermal gain stabilization, energy calibration methods, and the analysis event selection used to create our final 0[nu][beta][beta] search spectrum. We define our high level analysis procedures, with emphasis on the new insights gained and challenges encountered. We outline in detail our fitting methods near the hypothesized 0[nu][beta][beta] decay peak and catalog the main sources of systematic uncertainty. Finally, we derive the 0[nu][beta][beta] decay half-life limits previously reported for CUORE-0, T0[nu]1/2> 2.7×1024yr, and in combination with the Cuoricino limit, T0[nu]1/2> 4.0×1024yr.

Download or read book Investigation of Background Sources and Search for Neutrinoless Double beta Decay in CUORE written by Krystal Alfonso and published by . This book was released on 2022 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Two neutrino Double beta Decay Half life of Te with the CUORE 0 Experiment written by and published by . This book was released on 2017 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, we report on the measurement of the two-neutrino double-beta decay half-life of 130Te with the CUORE-0 detector. From an exposure of 33.4 kg year of TeO2, the half-life is determined to be T2[nu]1/2 = [8.2 ± 0.2 (stat.) ± 0.6 (syst.)] × 1020 year. This result is obtained after a detailed reconstruction of the sources responsible for the CUORE-0 counting rate, with a specific study of those contributing to the 130Te neutrinoless double-beta decay region of interest.

Download or read book First Results on Neutrinoless Double Beta Decay of Te 130 with the Calorimetric Cuoricino Experiment written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The first results are reported on the limit for neutrinoless double decay of 13°Te obtained with the new bolometric experiment CUORICINO. The set-up consists of 44 cubic crystals of natural TeO2, 5 cm on the side and 18 crystals of 3 x 3 x 6 cm3. Four of these latter crystals are made with isotopically enriched materials: two in 128Te and two others in 13°Te . With a sensitive mass of (almost equal to)40 kg, our array is by far the most massive running cryogenic detector to search for rare events. The array is operated at a temperature of (almost equal to)10 mK in a dilution refrigerator under a heavy shield in the Gran Sasso Underground Laboratory at a depth of about 3500 m.w.e. The counting rate in the region of neutrinoless double beta decay is (almost equal to)0.2 counts keV−1 kg−1 year−1, among the lowest in this type of experiment. No evidence for neutrinoless double beta decay is found with the present statistics obtained in about three months with a live time of 72%. The corresponding lower limit for the lifetime of this process is of 5.5 x 1023 years at 90% C.L. The corresponding limit for the effective neutrino mass ranges between 0.37 to 1.9 eV depending on the theoretically calculated nuclear matrix elements used. This constraint is the most restrictive one except those obtained with Ge diodes, and is comparable to them.

Download or read book Sensitivity of CUORE to Neutrinoless Double Beta Decay written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper, we study the sensitivity of CUORE, a bolometric double-beta decay experiment under construction at the Laboratori Nazionali del Gran Sasso in Italy. Two approaches to the computation of experimental sensitivity are discussed and compared, and the formulas and parameters used in the sensitivity estimates are provided. Assuming a background rate of 10−2 cts/(keV kg y), we find that, after 5 years of live time, CUORE will have a 1 [sigma] sensitivity to the neutrinoless double-beta decay half-life of {caret T{sup 0[nu]}{sub 1/2}}(1[sigma]) = 1.6x 1026 y and thus a potential to probe the effective Majorana neutrino mass down to 41-95 meV; the sensitivity at 1.64[sigma], which corresponds to 90% C.L., will be {caret T{sup 0[nu]}{sub 1/2}(1.64[sigma] }) = 9.5x1025 y. This range is compared with the claim of observation of neutrinoless double-beta decay in 76Ge and the preferred range in the neutrino mass parameter space from oscillation results.

Download or read book Background Model and a Measurement of the 2nbb Decay Rate in 130Te with CUORE 0 written by Xiaoyu Zhu and published by . This book was released on 2016 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: CUORE is a ton-scale cryogenic bolometer experiment designed to search for neutrinoless double beta decay ($0\nu\beta\beta$) in $^{130}$Te. CUORE-0 was a single array experiment consisting of 11 kg of $^{130}$Te and was designed to test the detector construction and analysis techniques for CUORE. CUORE-0 operated from 2013 to 2015 in the Laboratori Nazionali del Gran Sasso in Italy and collected a data sample of 9.8 kg$\cdot$yr of $^{130}$Te. This dissertation will focus on a method for reconstructing the background spectrum and extracting the two neutrino double beta decay ($2\nu\beta\beta$) signal of $^{130}$Te in CUORE-0. Identifying and reducing the most significant background contributions are keys to improving the sensitivity of future $0\nu\beta\beta$ experiments. The background spectrum of CUORE-0 was fit using the spectra of radioactive contaminants generated by Monte Carlo simulations and the $2\nu\beta\beta$ half-life was measured to be $T^{2\nu}_{1/2} = (8.27^{+1.38}_{-0.99} \text{(stat+syst)})\times10^{20} \text{ yr}$

Download or read book Energy Calibration for a Sensitive Search for Neutrinoless Double beta Decay written by and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Measurement of the 2 Neutrino Double Beta Decay Rate of Te 130 in the CUORICINO Experiment written by and published by . This book was released on 2011 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: CUORICINO was a cryogenic bolometer experiment designed to search for neutrinoless double beta decay and other rare processes, including double beta decay with two neutrinos (2v[beta][beta]). The experiment was located at Laboratori Nazionali del Gran Sasso and ran for a period of about 5 years, from 2003 to 2008. The detector consisted of an array of 62 TeO2 crystals arranged in a tower and operated at a temperature of 10 mK. Events depositing energy in the detectors, such as radioactive decays or impinging particles, produced thermal pulses in the crystals which were read out using sensitive thermistors. The experiment included 4 enriched crystals, 2 enriched with 130Te and 2 with 128Te, in order to aid in the measurement of the 2v[beta][beta] rate. The enriched crystals contained a total of 350 g 130Te. The 128-enriched (130-depleted) crystals were used as background monitors, so that the shared backgrounds could be subtracted from the energy spectrum of the 130- enriched crystals. Residual backgrounds in the subtracted spectrum were fit using spectra generated by Monte-Carlo simulations of natural radioactive contaminants located in and on the crystals. The 2v[beta][beta] half-life was measured to be T2v1/2 = [9.81± 0.96(stat)± 0.49(syst)] x1020 y.

Download or read book Cosmogenic Activation of TeO2 in the Neutrinoless Double Beta Decay Experiment CUORE written by Barbara Sue Wang and published by . This book was released on 2014 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Cryogenic Underground Observatory for Rare Events (CUORE) is an experiment that will search for neutrinoless double-beta (0 & nu & beta & beta) decay of 130Te and other rare processes. Observing 0 & nu & beta & beta decay would establish that neutrinos are massive Majorana fermions, demonstrate that lepton number is not conserved, and constrain the neutrino mass scale and hierarchy. The CUORE detector, currently being constructed underground at the Gran Sasso National Laboratory in Italy, is an array of 988 high-resolution TeO2 bolometers. Each bolometer is comprised of a thermistor and a TeO2 crystal that serves as both the source and the detector of 0 & nu & beta & beta decay. The 0 & nu & beta & beta decay signature for 130Te is a peak at the Q-value 2528 keV. Observation of 0 & nu & beta & beta decay requires that the background at the peak be ultra-low. Background-source identification and characterization are therefore extremely important. One source of background that is poorly characterized is activation of the TeO2 crystals by sea-level cosmic-ray neutrons. This process, known as cosmogenic activation, produces long-lived radioisotopes that can obscure the 0 & nu & beta & beta peak. Existing cross-section data is insufficient to estimate this background; therefore, an additional cross-section measurement has been performed in which a TeO2 target was irradiated with a neutron spectrum similar to that of cosmic-ray neutrons at sea-level. Analysis of the radionuclides produced reveals that 110mAg will dominate the cosmogenic activation background in CUORE. Estimations using the measured cross section for 110mAg indicate this source will be negligible compared with other contributions to the CUORE background.

Download or read book Search for Neutrinoless Double Beta Decay in 136Xe with EXO 200 written by and published by . This book was released on 2015 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: