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Search Results: 1 - 10 of 540358 matches for " L. M. Ejzak "
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The Search for Neutrinoless Double Beta Decay in CUORE
L. M. Ejzak,for the CUORE Collaboration
Physics , 2009,
Abstract: Understanding the nature of neutrino masses will require physics beyond the long-standing Standard Model of particle physics. Neutrinoless double beta decay experiments like the Cryogenic Underground Observatory for Rare Events (CUORE) are uniquely suited for probing the remaining mysteries of neutrino mass, particularly the question of the neutrino's Majorana nature. CUORE will be a next-generation experiment at the Laboratori Nazionali del Gran Sasso in Italy; it will consist of an array of 988 TeO2 detector crystals operated at ~10 mK, following the bolometric technique established by the Cuoricino experiment. It will look for the energy signal produced by the theoretically-predicted neutrinoless double beta decay in Te-130, and therefore reliable energy calibration of the detector is crucial to the experiment's success. We will present the most recent results from Cuoricino and discuss the current status of the CUORE project, with a particular emphasis on the development of the calibration system.
Terrestrial Consequences of Spectral and Temporal Variability in Ionizing Photon Events
Larissa M. Ejzak,Adrian L. Melott,Mikhail V. Medvedev,Brian C. Thomas
Physics , 2006, DOI: 10.1086/509106
Abstract: Gamma-Ray Bursts (GRBs) directed at Earth from within a few kpc may have damaged the biosphere, primarily though changes in atmospheric chemistry which admit greatly increased Solar UV. However, GRBs are highly variable in spectrum and duration. Recent observations indicate that short (~0.1 s) burst GRBs, which have harder spectra, may be sufficiently abundant at low redshift that they may offer an additional significant effect. A much longer timescale is associated with shock breakout luminosity observed in the soft X-ray (~10^3 s) and UV (~10^5 s) emission, and radioactive decay gamma-ray line radiation emitted during the light curve phase of supernovae (~10^7 s). Here we generalize our atmospheric computations to include a broad range of peak photon energies and investigate the effect of burst duration while holding total fluence and other parameters constant. The results can be used to estimate the probable impact of various kinds of ionizing events (such as short GRBs, X-ray flashes, supernovae) upon the terrestrial atmosphere. We find that the ultimate intensity of atmospheric effects varies only slightly with burst duration from 10^-1 s to 10^8 s. Therefore, the effect of many astrophysical events causing atmospheric ionization can be approximated without including time development. Detailed modeling requires specification of the season and latitude of the event. Harder photon spectra produce greater atmospheric effects for spectra with peaks up to about 20 MeV, because of greater penetration into the stratosphere.
Climatic and Biogeochemical Effects of a Galactic Gamma-Ray Burst
Adrian L. Melott,Brian C. Thomas,Daniel P. Hogan,Larissa M. Ejzak,Charles H. Jackman
Physics , 2005, DOI: 10.1029/2005GL023073
Abstract: It is likely that one or more gamma-ray bursts within our galaxy have strongly irradiated the Earth in the last Gy. This produces significant atmospheric ionization and dissociation, resulting in ozone depletion and DNA-damaging ultraviolet solar flux reaching the surface for up to a decade. Here we show the first detailed computation of two other significant effects. Visible opacity of NO2 is sufficient to reduce solar energy at the surface up to a few percent, with the greatest effect at the poles, which may be sufficient to initiate glaciation. Rainout of dilute nitric acid is could have been important for a burst nearer than our conservative nearest burst. These results support the hypothesis that the characteristics of the late Ordovician mass extinction are consistent with GRB initiation.
The low-temperature energy calibration system for the CUORE bolometer array
S. Sangiorgio,L. M. Ejzak,K. M. Heeger,R. H. Maruyama,A. Nucciotti,M. Olcese,T. S. Wise,A. L. Woodcraft
Physics , 2009, DOI: 10.1063/1.3292432
Abstract: The CUORE experiment will search for neutrinoless double beta decay (0nDBD) of 130Te using an array of 988 TeO_2 bolometers operated at 10 mK in the Laboratori Nazionali del Gran Sasso (Italy). The detector is housed in a large cryogen-free cryostat cooled by pulse tubes and a high-power dilution refrigerator. The TeO_2 bolometers measure the event energies, and a precise and reliable energy calibration is critical for the successful identification of candidate 0nDBD and background events. The detector calibration system under development is based on the insertion of 12 gamma-sources that are able to move under their own weight through a set of guide tubes that route them from deployment boxes on the 300K flange down into position in the detector region inside the cryostat. The CUORE experiment poses stringent requirements on the maximum heat load on the cryostat, material radiopurity, contamination risk and the ability to fully retract the sources during normal data taking. Together with the integration into a unique cryostat, this requires careful design and unconventional solutions. We present the design, challenges, and expected performance of this low-temperature energy calibration system.
Gamma-Ray Bursts and the Earth: Exploration of Atmospheric, Biological, Climatic and Biogeochemical Effects
Brian C. Thomas,Adrian L. Melott,Charles H. Jackman,Claude M. Laird,Mikhail V. Medvedev,Richard S. Stolarski,Neil Gehrels,John K. Cannizzo,Daniel P. Hogan,Larissa M. Ejzak
Physics , 2005, DOI: 10.1086/496914
Abstract: Gamma-Ray Bursts (GRBs) are likely to have made a number of significant impacts on the Earth during the last billion years. We have used a two-dimensional atmospheric model to investigate the effects on the Earth's atmosphere of GRBs delivering a range of fluences, at various latitudes, at the equinoxes and solstices, and at different times of day. We have estimated DNA damage levels caused by increased solar UVB radiation, reduction in solar visible light due to $\mathrm{NO_2}$ opacity, and deposition of nitrates through rainout of $\mathrm{HNO_3}$. For the ``typical'' nearest burst in the last billion years, we find globally averaged ozone depletion up to 38%. Localized depletion reaches as much as 74%. Significant global depletion (at least 10%) persists up to about 7 years after the burst. Our results depend strongly on time of year and latitude over which the burst occurs. We find DNA damage of up to 16 times the normal annual global average, well above lethal levels for simple life forms such as phytoplankton. The greatest damage occurs at low to mid latitudes. We find reductions in visible sunlight of a few percent, primarily in the polar regions. Nitrate deposition similar to or slightly greater than that currently caused by lightning is also observed, lasting several years. We discuss how these results support the hypothesis that the Late Ordovician mass extinction may have been initiated by a GRB.
Muon-induced backgrounds in the CUORICINO experiment
E. Andreotti,C. Arnaboldi,F. T. Avignone III,M. Balata,I. Bandac,M. Barucci,J. W. Beeman,F. Bellini,T. Bloxham,C. Brofferio,A. Bryant,C. Bucci,L. Canonica,S. Capelli,L. Carbone,M. Carrettoni,M. Clemenza,O. Cremonesi,R. J. Creswick,S. Di Domizio,M. J. Dolinski,L. Ejzak,R. Faccini,H. A. Farach,E. Ferri,F. Ferroni,E. Fiorini,L. Foggetta,A. Giachero,L. Gironi,A. Giuliani,P. Gorla,E. Guardincerri,T. D. Gutierrez,E. E. Haller,R. Kadel,K. Kazkaz,S. Kraft,L. Kogler,Yu. G. Kolomensky,C. Maiano,R. H. Maruyama,C. Martinez,M. Martinez,L. Mizouni,S. Morganti,S. Nisi,C. Nones,E. B. Norman,A. Nucciotti,F. Orio,M. Pallavicini,V. Palmieri,L. Pattavina,M. Pavan,M. Pedretti,G. Pessina,S. Pirro,E. Previtali,L. Risegari,C. Rosenfeld,C. Rusconi,C. Salvioni,S. Sangiorgio,D. Schaeffer,N. D. Scielzo,M. Sisti,A. R. Smith,C. Tomei,G. Ventura,M. Vignati
Physics , 2009, DOI: 10.1016/j.astropartphys.2010.04.004
Abstract: To better understand the contribution of cosmic ray muons to the CUORICINO background, 10 plastic scintillator detectors were installed at the CUORICINO site and operated during the final 3 months of the experiment. From these measurements, an upper limit of 0.0021 counts/(keV kg yr) (95% CL) was obtained on the cosmic ray-induced background in the neutrinoless double beta decay region of interest. The measurements were also compared to Geant4 simulations.
Search for beta plus/EC double beta decay of 120Te
E. Andreotti,C. Arnaboldi,F. T. Avignone III,M. Balata,I. Bandac,M. Barucci,J. W. Beeman,F. Bellini,C. Brofferio,A. Bryant,C. Bucci,L. Canonica,S. Capelli,L. Carbone,M. Carrettoni,M. Clemenza,O. Cremonesi,R. J. Creswick,S. Di Domizio,M. J. Dolinski,L. Ejzak,R. Faccini,H. A. Farach,E. Ferri,E. Fiorini,L. Foggetta,A. Giachero,L. Gironi,A. Giuliani,P. Gorla,E. Guardincerri,T. D. Gutierrez. E. E. Haller,K. Kazkaz,S. Kraft,L. Kogler,C. Maiano,R. H. Maruyama,C. Martinez,M. Martinez,L. Mizouni,S. Newman,S. Nisi,C. Nones,E. B. Norman,A. Nucciotti,F. Orio,M. Pallavicini,V. Palmieri,L. Pattavina,M. Pavan,M. Pedretti,G. Pessina,S. Pirro,E. Previtali,L. Risegari,C. Rosenfeld,C. Rusconi,C. Salvioni,S. Sangiorgio,D. Schaeffer,N. D. Scielzo,M. Sisti,A. R. Smith,C. Tomei,G. Ventura,M. Vignati
Physics , 2010, DOI: 10.1016/j.astropartphys.2010.12.011
Abstract: We present a search for beta plus/EC double beta decay of 120Te performed with the CUORICINO experiment, an array of TeO2 cryogenic bolometers. After collecting 0.0573 kg y of 120Te, we see no evidence of a signal and therefore set the following limits on the half-life: T1/2 (0nu) > 1.9 10^{21} y at 90% C.L. for the 0 neutrino mode and T1/2 (2nu) > 7.6 10^{19} y at 90% C.L. for the two neutrino mode. These results improve the existing limits by almost three orders of magnitude (four in the case of 0 neutrino mode).
Double-beta decay of $^{130}$Te to the first 0$^{+}$ excited state of $^{130}$Xe with CUORICINO
E. Andreotti,C. Arnaboldi,F. T. Avignone III,M. Balata,I. Bandac,M. Barucci,J. W. Beeman,F. Bellini,C. Brofferio,A. Bryant,C. Bucci,L. Canonica,S. Capelli,L. Carbone,M. Carrettoni,M. Clemenza,O. Cremonesi,R. J. Creswick,S. Di Domizio,M. J. Dolinski,L. Ejzak,R. Faccini,H. A. Farach,E. Ferri,E. Fiorini,L. Foggetta,A. Giachero,L. Gironi,A. Giuliani,P. Gorla,E. Guardincerri,T. D. Gutierrez,E. E. Haller,K. Kazkaz,L. Kogler,S. Kraft,C. Maiano,C. Martinez,M. Martinez,R. H. Maruyama,S. Newman,S. Nisi,C. Nones,E. B. Norman,A. Nucciotti,F. Orio,M. Pallavicini,V. Palmieri,L. Pattavina,M. Pavan,M. Pedretti,G. Pessina,S. Pirro,E. Previtali,L. Risegari,C. Rosenfeld,C. Rusconi,C. Salvioni,S. Sangiorgio,D. Schaeffer,N. D. Scielzo,M. Sisti,A. R. Smith,C. Tomei,G. Ventura,M. Vignati
Physics , 2011, DOI: 10.1103/PhysRevC.85.045503
Abstract: The CUORICINO experiment was an array of 62 TeO$_{2}$ single-crystal bolometers with a total $^{130}$Te mass of $11.3\,$kg. The experiment finished in 2008 after more than 3 years of active operating time. Searches for both $0\nu$ and $2\nu$ double-beta decay to the first excited $0^{+}$ state in $^{130}$Xe were performed by studying different coincidence scenarios. The analysis was based on data representing a total exposure of N($^{130}$Te)$\cdot$t=$9.5\times10^{25}\,$y. No evidence for a signal was found. The resulting lower limits on the half lives are $T^{2\nu}_{1/2}(^{130} Te\rightarrow^{130} Xe^{*})>1.3\times10^{23}\,$y (90% C.L.), and $T^{0\nu}_{1/2}(^{130} Te\rightarrow^{130} Xe^{*})>9.4\times10^{23}\,$y (90% C.L.).
130Te Neutrinoless Double-Beta Decay with CUORICINO
E. Andreotti,C. Arnaboldi,F. T. Avignone III,M. Balata,I. Bandac,M. Barucci,J. W. Beeman,F. Bellini,C. Brofferio,A. Bryant,C. Bucci,L. Canonica,S. Capelli,L. Carbone,M. Carrettoni,M. Clemenza,O. Cremonesi,R. J. Creswick,S. Di Domizio,M. J. Dolinski,L. Ejzak,R. Faccini,H. A. Farach,E. Ferri,E. Fiorini,L. Foggetta,A. Giachero,L. Gironi,A. Giuliani,P. Gorla,E. Guardincerri,T. D. Gutierrez,E. E. Haller,K. Kazkaz,S. Kraft,L. Kogler,C. Maiano,R. H. Maruyama,C. Martinez,M. Martinez,S. Newman,S. Nisi,C. Nones,E. B. Norman,A. Nucciotti,F. Orio,M. Pallavicini,V. Palmieri,L. Pattavina,M. Pavan,M. Pedretti,G. Pessina,S. Pirro,E. Previtali,L. Risegari,C. Rosenfeld,C. Rusconi,C. Salvioni,S. Sangiorgio,D. Schaeffer,N. D. Scielzo,M. Sisti,A. R. Smith,C. Tomei,G. Ventura,M. Vignati
Physics , 2010, DOI: 10.1016/j.astropartphys.2011.02.002
Abstract: We report the final result of the CUORICINO experiment. Operated between 2003 and 2008, with a total exposure of 19.75 kg y of 130Te, CUORICINO was able to set a lower bound on the 130Te 0nDBD half-life of 2.8 10^{24} years at 90% C.L. The limit here reported includes the effects of systematic uncertainties that are examined in detail in the paper. The corresponding upper bound on the neutrino Majorana mass is in the range 300--710 meV, depending on the adopted nuclear matrix element evaluation.
The CUORE and CUORE-0 Experiments at Gran Sasso
A. Giachero,D. R. Artusa,F. T. Avignone III,O. Azzolini,M. Balata,T. I. Banks,G. Bari,J. Beeman,F. Bellini,A. Bersani,M. Biassoni,C. Brofferio,C. Bucci,X. Z. Cai,A. Camacho,A. Caminata,L. Canonica,X. G. Cao,S. Capelli,L. Cappelli,L. Carbone,L. Cardani,N. Casali,L. Cassina,D. Chiesa,N. Chott,M. Clemenza,S. Copello,C. Cosmelli,O. Cremonesi,R. J. Creswick,J. S. Cushman,I. Dafinei,A. Dally,V. Datskov,S. Dell'Oro,M. M. Deninno,S. Di Domizio,M. L. di Vacri,A. Drobizhev,L. Ejzak,D. Q. Fang,H. A. Farach,M. Faverzani,G. Fernandes,E. Ferri,F. Ferroni,E. Fiorini,M. A. Franceschi,S. J. Freedman,B. K. Fujikawa,L. Gironi,A. Giuliani,P. Gorla,C. Gotti,T. D. Gutierrez,E. E. Haller,K. Han,K. M. Heeger,R. Hennings-Yeomans,K. P. Hickerson,H. Z. Huang,R. Kadel,K. Kazkaz,G. Keppel,Yu. G. Kolomensky,Y. L. Li,C. Ligi,K. E. Lim,X. Liu,Y. G. Ma,C. Maiano,M. Maino,M. Martinez,R. H. Maruyama,Y. Mei,N. Moggi,S. Morganti,T. Napolitano,M. Nastasi,S. Nisi,C. Nones,E. B. Norman,A. Nucciotti,T. O'Donnell,F. Orio,D. Orlandi,J. L. Ouellet,C. E. Pagliarone,M. Pallavicini,L. Pattavina,M. Pavan,M. Pedretti,G. Pessina,V. Pettinacci,G. Piperno,C. Pira,S. Pirro,S. Pozzi,E. Previtali,V. Rampazzo,C. Rosenfeld,C. Rusconi,E. Sala,S. Sangiorgio,N. D. Scielzo,M. Sisti,A. R. Smith,L. Taffarello,M. Tenconi,F. Terranova,W. D. Tian,C. Tomei,S. Trentalange,G. Ventura,M. Vignati,B. S. Wang,H. W. Wang,L. Wielgus,J. Wilson,L. A. Winslow,T. Wise,A. Woodcraft,L. Zanotti,C. Zarra,G. Q. Zhang,B. X. Zhu,S. Zucchelli
Physics , 2014, DOI: 10.1051/epjconf/20149504024
Abstract: The Cryogenic Underground Observatory for Rare Events (CUORE) is an experiment to search for neutrinoless double beta decay ($0\nu\beta\beta$) in $^{130}$Te and other rare processes. CUORE is a cryogenic detector composed of 988 TeO$_2$ bolometers for a total mass of about 741 kg. The detector is being constructed at the Laboratori Nazionali del Gran Sasso, Italy, where it will start taking data in 2015. If the target background of 0.01 counts/(keV$\cdot$kg$\cdot$y) will be reached, in five years of data taking CUORE will have an half life sensitivity around $1\times 10^{26}$ y at 90\% C.L. As a first step towards CUORE a smaller experiment CUORE-0, constructed to test and demonstrate the performances expected for CUORE, has been assembled and is running. The detector is a single tower of 52 CUORE-like bolometers that started taking data in spring 2013. The status and perspectives of CUORE will be discussed, and the first CUORE-0 data will be presented.
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