Download or read book Discovery of the Two neutrino Double beta Decay of Xenon 136 with EXO 200 written by Russell Geoffrey Neilson and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent neutrino oscillation measurements provide definitive evidence for non-zero neutrino masses. Oscillation measurements, however, only measure mass differences, not the absolute mass scale. Neutrinoless double-beta decay, a hypothetical nuclear transition, can probe the absolute neutrino mass scale. This process, if observed, would also imply that neutrinos are their own anti-particles and that lepton number is not a conserved quantity. The 200 kg Enriched Xenon Observatory (EXO-200) detector is currently taking data to search for the neutrinoless double-beta decay of Xe-136, with an expected half-life in excess of 10^25 years. Located at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico, the detector is filled with 200 kg of isotopically enriched liquid xenon. The analysis presented here describes the recent observation with EXO-200 of the two-neutrino double beta-decay of Xe-136. This is the rarest process ever directly observed with a half-life of 2.11+-0.21 x 10^21 years and provides important input to the measurement of the neutrinoless decay.

Download or read book Double Beta Decay in Xenon 136 Measuring the Neutrino Emitting Mode and Searching for Majoron Emitting Modes written by and published by . This book was released on 2013 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observations of neutrino flavor oscillations have demonstrated that neutrinos have mass. Since the discovery of these oscillations, much progress has been made at mea- suring the neutrino mass-squared differences and lepton mixing angles that character- ize them. However, the origin and absolute scale of neutrino masses remain unknown. Unique among fermions, neutrinos can be Majorana particles, which could provide an explanation for neutrino masses. Discovery of a hypothetical process known as neutrinoless double beta decay would show that neutrinos are Majorana particles and determine the mass scale for neutrinos. The Enriched Xenon Observatory (EXO) is a series of experiments searching for the neutrinoless double beta decay of 136Xe. The first experiment, EXO-200, began operation in 2011 and makes use of 200 kg of xenon enriched to 80.6% in 136Xe. The analysis presented here makes use of data from EXO-200 to obtain a more precise measurement of the half-life for the two-neutrino-emitting mode of double beta decay than previously reported. The analysis also sets limits on the half-lives for exotic, Majoron-emitting modes of neutrinoless double beta decay. Data from EXO-200 is also used to produce a measurement of the cosmic muon flux at the WIPP under- ground site where EXO-200 is located.

Download or read book Double Beta Decay in Xenon 136 written by Steven Herrin and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Observations of neutrino flavor oscillations have demonstrated that neutrinos have mass. Since the discovery of these oscillations, much progress has been made at measuring the neutrino mass-squared differences and lepton mixing angles that characterize them. However, the origin and absolute scale of neutrino masses remain unknown. Unique among fermions, neutrinos can be Majorana particles, which could provide an explanation for neutrino masses. Discovery of a hypothetical process known as neutrinoless double beta decay would show that neutrinos are Majorana particles and determine the mass scale for neutrinos. The Enriched Xenon Observatory (EXO) is a series of experiments searching for the neutrinoless double beta decay of xenon-136. The first experiment, EXO-200, began operation in 2011 and makes use of 200 kg of xenon enriched to 80.6% in xenon-136. The analysis presented here makes use of data from EXO-200 to obtain a more precise measurement of the half-life for the two-neutrino-emitting mode of double beta decay than previously reported. The analysis also sets limits on the half-lives for exotic, Majoron-emitting modes of neutrinoless double beta decay. Data from EXO-200 is also used to produce a measurement of the cosmic muon flux at the WIPP underground site where EXO-200 is located.

Download or read book A Search for Double Beta Decay of Xenon to Excited States of Barium with EXO 200 written by Sereres Johnston and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents searches for several modes of double beta decays of 136Xe to two low-lying excited levels of 136Ba. For each final level, both 2[nu] and 0[nu] double beta decay processes are considered. The data and general techniques developed by the EXO-200 collaboration are used, including a Machine Learning process to improve sensitivity in multivariate space. EXO-200 is an experimental program searching for 0[nu][beta][beta] decay in a time projection chamber filled with 175 kg of liquid Xenon enriched to 80% 136Xe, functioning as both source and detector. Experimental searches of double beta decay with 136Xe and other isotopes are motivated by non Standard Model neutrinoless decay (0[nu][beta][beta]) possibilities. If found this would imply the Majorana nature of neutrinos, provide access to the currently unknown absolute mass scale of the neutrino, and violate lepton conservation by 2 units. Nuclear matrix elements necessary to connecting observed neutrinoless halflife to the neutrino mass scale depend on nuclear models. Observation of both the 2[nu] 0+ excited and 0+ ground state in a single element may constrain these models. Sensitivity studies of search performance are described, and final sensitivities from 7.86 · 10^23 years to 2.00 · 10^25 years are reported.

Download or read book The Search for Zero Neutrino Double Beta Decay in 136 Xe with EXO 200 written by Kevin Patrick O'Sullivan and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This analysis reports a search for the neutrinoless double decay (0[nu][beta][beta]) of 136-Xe with the EXO-200 detector. 0[nu][beta][beta] is a hypothetical nuclear process which only occurs if neutrinos are so called Majorana particles, which are there own anti-particles, as opposed to Dirac particles which have separate anti-particles. The search for 0[nu][beta][beta] is currently the most experimentally viable technique to address the Dirac or Majorana nature of neutrinos. The EXO-200 experiment is a liquid xenon time projection cham- ber operating 655 meters underground at the Waste Isolation Pilot Plant (WIPP) with 200 kg of xenon enriched to 80.6% in the isotope 136-Xe. A total of one event in the one sigma region of interest is observed with background of (1.5 ± .1) × 10^-3 counts/keV/kg/yr. This places a limit on the 0[nu][beta][beta] half-life of 136Xe is of 1.59×10^25.

Download or read book The Search for Majoron Emission in Xenon 136 and Two neutrino Double beta Decay of Xenon 134 with the Enriched Xenon Observatory written by Josiah Walton and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Xe 136 Two neutrino Double Beta Decay Half life with the NEXT White Detector written by Alberto Usón Andrés and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Double Beta Decay Half life of sup 136 Xe in KamLAND Zen written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results from the KamLAND-Zen double-beta decay experiment based on an exposure of 77.6 days with 129 kg of 136Xe. The measured two-neutrino double-beta decay half-life of 136Xe is T{sup 2[nu]}{sub 1/2} = 2:38 ± 0:02(stat) ±0.14(syst) x1021 yr, consistent with a recent measurement by EXO-200. We also obtain a lower limit for the neutrinoless double-beta decay half-life, T{sup 0[nu]}{sub 1/2}> 5.7 x 1024 yr at 90% C.L.

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:

Download or read book Searching for Double Beta Decay with the Enriched Xenon Observatory written by and published by . This book was released on 2007 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Enriched Xenon Observatory (EXO) Collaboration is building a series of experiments to search for the neutrinoless double beta decay of 136Xe. The first experiment, known as EXO-200, will utilize 200 kg of xenon enriched to 80% in the isotope of interest, making it the largest double beta decay experiment to date by one order of magnitude. This experiment is rapidly being constructed, and will begin data taking in 2007. The EXO collaboration is also developing a technique to identify on an event-by-event basis the daughter barium ion of the double beta decay. If successful, this method would eliminate all conventional radioactive backgrounds to the decay, resulting in an ideal experiment. We summarize here the current status of EXO-200 construction and the barium tag R & D program.

Download or read book Double Beta Decay in 136Xe written by and published by . This book was released on 1986 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for Neutrinoless Double beta Decay and 42Ar in Enriched Xenon Using the EXO 200 Dataset written by Mitchell Hughes and published by . This book was released on 2020 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observation of neutrinoless double-beta decay (0ÎưÎøÎø) would constitute discovery of a new class of particle (the Majorana neutrino), violate lepton number conservation, and provide a constraint on the neutrino mass scale. The Enriched Xenon Observatory experiment (EXO-200) operated an extremely radio-pure tracking calorimeter filled with liquid xenon enriched in the candidate isotope 136Xe and installed underground in New Mexico, USA. The author presents a search for 0ÎưÎøÎø with the complete EXO-200 dataset, the second-largest exposure of any 0ÎưÎøÎø experiment (234.1 kg8́9yr). The analysis applied coupled fits to event energy and position with a classical topological discriminator. The author produced an expanded background model to search for radioactive 42Ar via its Îø-decay product, 42K. No signal excess was observed near the 0ÎưÎøÎø Q-value, leading to a limit on the 0ÎưÎøÎø half-life in 136Xe of T_(1/2)^0Îư >3.0©710^25 yr and Majorana neutrino mass 0̂8m_ÎøÎø 0̂9

Download or read book Seventy Years Of Double Beta Decay From Nuclear Physics To Beyond standard model Particle Physics written by Hans Volker Klapdor-kleingrothaus and published by World Scientific. This book was released on 2010-03-25 with total page 1559 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last 20 years the disciplines of particle physics, astrophysics, nuclear physics and cosmology have grown together in an unprecedented way. A brilliant example is nuclear double beta decay, an extremely rare radioactive decay mode, which is one of the most exciting and important fields of research in particle physics at present and the flagship of non-accelerator particle physics.While already discussed in the 1930s, only in the 1980s was it understood that neutrinoless double beta decay can yield information on the Majorana mass of the neutrino, which has an impact on the structure of space-time. Today, double beta decay is indispensable for solving the problem of the neutrino mass spectrum and the structure of the neutrino mass matrix. The potential of double beta decay has also been extended such that it is now one of the most promising tools for probing beyond-the-standard-model particle physics, and gives access to energy scales beyond the potential of future accelerators.This book presents the breathtaking manner in which achievements in particle physics have been made from a nuclear physics process. Consisting of a 150-page highly factual overview of the field of double beta decay and a 1200-page collection of the most important original articles, the book outlines the development of double beta decay research — theoretical and experimental — from its humble beginnings until its most recent achievements, with its revolutionary consequences for the theory of particle physics. It further presents an outlook on the exciting future of the field.

Download or read book Sixty Years Of Double Beta Decay From Nuclear Physics To Beyond Standard Model written by Hans Volker Klapdor-kleingrothaus and published by World Scientific. This book was released on 2001-04-30 with total page 1313 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear double beta decay is one of the most promising tools for probing beyond-the-standard-model physics on beyond-accelerator energy scales. It is already now probing the TeV scale, on which new physics should manifest itself according to theoretical expectations. Only in the early 1980s was it known that double beta decay yields information on the Majorana mass of the exchanged neutrino. At present, the sharpest bound for the electron neutrino mass arises from this process. It is only in the last 10 years that the much more far-reaching potential of double beta decay has been discovered. Today, the potential of double beta decay includes a broad range of topics that are equally relevant to particle physics and astrophysics, such as masses of heavy neutrinos, of sneutrinos, as SUSY models, compositeness, leptoquarks, left-right symmetric models, and tests of Lorentz symmetry and equivalence principle in the neutrino sector. Double beta decay has become indispensable nowadays for solving the problem of the neutrino mass spectrum and the structure of the neutrino mass matrix — together with present and future solar and atmospheric neutrino oscillation experiments. Some future double beta experiments (like GENIUS) will be capable to be simultaneously neutrino observatories for double beta decay and low-energy solar neutrinos, and observatories for cold dark matter of ultimate sensitivity.This invaluable book outlines the development of double beta research from its beginnings until its most recent achievements, and also presents the outlook for its highly exciting future.

Download or read book Towards a Precision Measurement of the Half Life of Neutrinoless Double Beta Decay of 136Xe written by Francisco Richard LePort and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent neutrino oscillation experiments provide proof that neutrinos are massive par- ticles, but the absolute neutrino mass scale remains unknown. Observation of neu- trinoless double beta-decay (0vBB), a hypothetical nuclear transition, would provide information on the absolute neutrino mass scale. This decay violates lepton number conservation and requires that neutrinos are massive Majorana particles. Current limits on the half-life of 0vBB are in excess of 10^25 yr. The 200 kg Enriched Xenon Observatory experiment (EXO-200) is a double beta-decay exper- iment designed to improve upon this limit. It is currently in the early stages of commissioning at the Waste Isolation Pilot Plant near Carlsbad, New Mexico. This work discusses first the use of liquid xenon as source and detector medium for double beta decay. The design and construction of EXO-200 is then presented, including a detailed prediction of detector backgrounds and sensitivity.

Download or read book Sixty Years of Double Beta Decay written by H. V. Klapdor-Kleingrothaus and published by World Scientific. This book was released on 2001 with total page 1324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear double beta decay is one of the most promising tools for probing beyond-the-standard-model physics on beyond-accelerator energy scales. It is already now probing the TeV scale, on which new physics should manifest itself according to theoretical expectations. Only in the early 1980s was it known that double beta decay yields information on the Majorana mass of the exchanged neutrino. At present, the sharpest bound for the electron neutrino mass arises from this process. It is only in the last 10 years that the much more far-reaching potential of double beta decay has been discovered. Today, the potential of double beta decay includes a broad range of topics that are equally relevant to particle physics and astrophysics, such as masses of heavy neutrinos, of sneutrinos, as SUSY models, compositeness, leptoquarks, left-right symmetric models, and tests of Lorentz symmetry and equivalence principle in the neutrino sector. Double beta decay has become indispensable nowadays for solving the problem of the neutrino mass spectrum and the structure of the neutrino mass matrix OCo together with present and future solar and atmospheric neutrino oscillation experiments. Some future double beta experiments (like GENIUS) will be capable to be simultaneously neutrino observatories for double beta decay and low-energy solar neutrinos, and observatories for cold dark matter of ultimate sensitivity. This invaluable book outlines the development of double beta research from its beginnings until its most recent achievements, and also presents the outlook for its highly exciting future. Contents: Double Beta Decay OCo Historical Retrospective and Perspectives; Original Articles: From the Early Days until the Gauge Theory Era; The Nuclear Physics Side OCo Nuclear Matrix Elements; The Nuclear Physics Side OCo Nuclear Matrix Elements; Effective Neutrino Masses from Double Beta Decay, Neutrino Mass Models and Cosmological Parameters OCo Present Status and Prospects; Other Beyond Standard Model Physics: From SUSY and Leptoquarks to Compositeness and Quantum Foam; The Experimental Race: From the Late Eighties to the Future; The Future of Double Beta Decay; Appendices: Ten Years of HeidelbergOCoMoscow Experiment; The Potential Future OCo GENIUS. Readership: Particle physicists, nuclear physicists and astrophysicists."

Download or read book New Technique for Barium Daughter Ion Identification in a Liquid Xe 136 Double Beta Decay Experiment written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work addresses long-standing issues of fundamental interest in elementary particle physics. The most important outcome of this work is a new limit on neutrinoless double beta decay. This is an extremely rare and long sought after type of radioactive decay. If discovered, it would require changes in the standard model of the elementary constituents of matter, and would prove that neutrinos and antineutrinos are the same, a revolutionary concept in particle physics. Neutrinos are major components of the matter in the universe that are so small and so weakly interacting with other matter that their masses have not yet been discovered. A discovery of neutrinoless double beta decay could help determine the neutrino masses. An important outcome of the work on this project was the Colorado State University role in operating the EXO-200 neutrinoless double beta decay experiment and in analysis of the data from this experiment. One type of double beta decay of the isotope 136Xe, the two-neutrino variety, was discovered in this work. Although the other type of double beta decay, the neutrinoless variety, was not yet discovered in this work, a world's best sensitivity of 1.9x1025 year half-life was obtained. This result rules out a previous claim of a positive result in a different isotope. This work also establishes that the masses of the neutrinos, are less than one millionth of that of electrons. A unique EXO-200 analysis, in which the CSU group had a leading role, has established for the first time ever in a liquid noble gas the fraction of daughter atoms from alpha and beta decay that are ionized. This result has important impact on other pending studies, including nucleon decay and barium tagging. Novel additional discoveries include multiphoton ionization of liquid xenon with UV pulsed lasers, which may find application in calibration of future noble liquid detectors, and studies of association and dissociation reactions of Ba+ ions in gaseous xenon. Through this project, we are substantially closer to demonstrating "barium tagging", i.e., detection of single daughter 136Ba atoms from 136Xe double beta decay. Milestones achieved include obtaining spectra of small numbers of Ba atoms and cryoprobe advances toward trapping single 136Ba atoms in solid xenon and probe extraction for detection. One of the other benefits to society is the training of six Ph. D. students in a variety of state-of-the-art technologies, half under primary support of this grant and half with partial support, with four finishing their Ph. D. degrees and two well on their way.