DOCSLIB.ORG

The Search for 0Νββ Decay: a Look at Four Experiments

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Search for 0Νββ Decay: a Look at Four Experiments The Search for 0νββ Decay: A Look at Four Experiments Cameron Sumner April 30, 2018 Abstract Background: Double beta (2νββ) decay is a process in certain isotopes where two neutrons decay into two protons and emit two electrons and two electron-neutrinos. If neutrinos are their own antiparticles (called Majorana particles), a theoretical neutrinoless beta decay (0νββ), where the two neutrinos annihilate each other, should be possible. Four experiments are searching for evidence of this decay. Purpose: Searching for lepton number violation via neutrinoless beta decay (0νββ), which would prove that neutrinos are Majorana particles. Methods: Each experiment observes the decay of certain isotopes that undergo 2νββ decay in the search for 0νββ decay. The methods and isotopes used are all slightly different, but they all measure energy absorption from the decay. If 0νββ decay is observed, the resulting energy absorption would include the energy of the missing neutrinos. Results: No evidence of 0νββ decay has been found. Each experiment found a lower limit of the decay ranging from 푇/( 푋푒) > 1.0 푥 10 푦푟 to 푇/( 퐺푒) > 8.0 푥 10 푦푟 (all at 90% confidence level). An upper limit on the mass of Majorana neutrinos is shown to be within the range 푚 < (120 − 520) 푚푒푉. Conclusion: While there has not been evidence of 0νββ decay yet, continued technological advancements will increase the sensitivity of the detectors and the total mass of the isotope allowed while still being protected from background, and decrease the background noise. 1 The current interpretation of the standard model is incomplete. Currently, it is believed that each charged lepton (the electron, muon, and tauon, and their antiparticles) each have their own corresponding neutrino or antineutrino, which helps conserve lepton number in reactions. For example, consider the decay of the pion: 휋 →μ + 휈̅ The pion decays into an antimuon and a muon antineutrino. Each generation of leptons has a different lepton number (denoted as Lx, where x is the specific lepton generation) attached to it. As the Lµ for the pion is zero, the creation of the antimuon (whose Lµ=-1) must be accompanied by the muon neutrino to conserve Lµ (whose Lµ=1). However, the discovery of neutrino oscillations (where neutrinos oscillate between the three generations) shows the absolute nature of this to be untrue. And while the standard model says total lepton number is conserved, the doubt cast by neutrino oscillations, and the overall lack of knowledge on the nature of neutrinos has inspired several experiments in search of violation of total lepton number. The debate currently centers around whether neutrinos are Dirac particles (the current interpretation) or Majorana particles (particles that are their own antiparticles) and the search for neutrinoless double beta decay (0νββ). Observations of this process would prove that total lepton number is violated and that neutrinos are Majorana particles, giving us proof of physics beyond the Fig. 1: An artistic representation of 0νββ decay. Left: a normal 2νββ decay. Middle: 0νββ decay. Right: A possible example of 0νββ decay with a new, standard model. “Ordinary two-neutrino heavier element. [Credit: APS/Alan Stonebraker] “Viewpoint: The Hunt for No Neutrinos” https://physics.aps.org/articles/v11/30 (2018) double-beta decay (2νββ) is an uncommon 2 process in which two neutrons decay into two protons, two electrons, and two antineutrinos at the same time (shown in Fig. 1, left). However, if neutrinos and antineutrinos are identical, then the two antineutrinos can annihilate each other, resulting in a neutrinoless decay (shown in Fig. 1, middle) antineutrinos at the same time.” [6] These four experimental collaborations have reported new lower limits of the decay’s half-life within the past two months. The purposes of these experiments are all nearly identical, to find a 0νββ decay, and determine the lower bounds of the half-life of the decay. They all do it in a similar fashion. Each experiment monitors a large number of atoms of a given isotope that supports 2νββ decay, and searches for peaks in the energy of the electrons involved in the decay that would indicate the two neutrinos have annihilated. These experiments, however, differ in the isotope used, and how they measure electron energies. GERDA (the GERmanium Detector Array), located at the underground Laboratori Nazionali del Gran Sasso (LNGS) below Gran Sasso mountain in L’Aquila, Italy [2-3], and the Majorana Demonstrator [1], located at the Sanford Underground Research Facility in Lead, South Dakota, use 76Ge. CUORE (the Cryogenic Underground Observatory for Rare Events), also located at the LNGS [4], uses 130Te. EXO-200 (the Enriched Xenon Observatory), located at the Waste Isolation Pilot Plant near Carlsbad, New Mexico [5], uses 136Xe. Each experiment found the half-life of 0νββ decay to be on the order of 1025 years. This is why such a large amount of the isotope is necessary. Half-life is not “the time required for exactly half of the entities to decay.” It’s a measurement of the average time for half of the entities to decay. So, to simulate a half-life on that scale, hundreds of kilograms of the isotopes (which translates to ~1025 atoms) are used with the intention of only a relatively few of them to decay. 3 The experiments all use similar methods to shield the experiment from outside background. Lead is copiously used, and, except for the CUORE experiment, a device is used to veto muon-induced events. Each experiment carefully selects events that could possibly be candidates for 0νββ decay. The CUORE experiments focuses on the decay in 130Te to the ground state of 130Xe. CUORE is 3 composed of 988 5 x 5 x 5 cm TeO2 crystals, each having a mass of 750 g (equaling 741 kg of TeO2), which can be cooled to temperatures as low as 7 mK. The crystals are arranged into 19 copper-framed towers, with each tower containing 13 floors of 4 crystals. These crystals are held in the frame by polytetrafluoroethylene (PTFE) supports. The towers are thermally connected to the mixing chamber of a 3He—4He dilution refrigerator, which is precooled by five two-stage pulse tube coolers (at approximately 40 and 4 K) and an expansion valve. Two lead shields are integrated to suppress external γ-ray backgrounds. In addition, an external lead shield surrounded by PTFE mixed with boric acid provide additional shielding. When a crystal absorbs energy, the resulting temperature increase is used to measure that energy. To accomplish this, each crystal is equipped with a thermistor (an electrical resistor whose resistance changes when heated) that is used to record thermal pulses. The data are from two month-long data collection periods which ran from May to June (dataset 1) and August to September (dataset 2) of 2017. Between the two collection periods, an active noise cancellation system was implemented on the coolers. Each collection period ended with periods devoted to calibration with 232Th γ-ray sources. This was done to verify the stability of the detector response through the collection period. In the end, it was concluded that there was no evidence for 0νββ decay of 130Te. A lower limit of the half-life was placed at 푇/( 푇푒) > 1.3 푥 10 푦푟. This combined with previous experiments from the CUORE collaboration (Cuoricino and CUORE-0) show a lower limit of 푇/( 푇푒) > 1.5 푥 10 푦푟, both of these at 90% confidence level. 4 EXO-200 (200 kg on xenon at the Enriched Xenon Observatory) is searching for 0νββ decay in 136Xe. It uses a time projection chamber (TPC), which is a particle detector that uses electric and magnetic fields in a volume of gas or liquid (in this case, a liquid), to perform reconstructions of particle interactions. The TPC is filled with liquid xenon (LXe) enriched to 80.6% 136Xe. The TPC has two drift regions split by a common cathode, each with radii of about 18 cm, and drift lengths of about 20 cm. Xenon is a scintillator, meaning it flashes light when excited by ionizing radiation. Decay particles produce light. This fact is exploited by arrays of avalanche photodiodes (APDs), which are highly sensitive and convert this light to electricity. This light is used to determine event time. A large electric field drives ionization electrons to wires for collection. The time between the light and first collection determines the z coordinate of the event, while a grid of wires determines the x and y coordinated. The total energy deposited is determined from the combination of the charge and light signals. The LXe is surrounded by several layers of passive and active shielding, including HFE-7000 cryofluid, lead, and a plastic scintillator muon veto. In addition, the Waste Isolation Pilot Plant provides an overburden of water. Like the other experiments, there is a minimum time between events required to avoid mixing between events. In this case, they are required to be 1 s from all other events. In this experiment, the data were collected in two phases. 80% of the data came Phase I, which ran from Sep. 2011 to Feb. 2014. This phase ended when EXO-200 was forced to suspend operations, because of accidents at the WIPP facility. The other 20% came from Phase II, which began in May 2016 (There isn’t an end date stated in the paper, but the manuscript was first received 1 August 2017, so I believe it ended before that.). Between the two phases, the detector was upgraded with new electronics to improve the background and readout noise. Because of these upgrades, the phase II sensitivity is comparable to that of Phase I.
Load more

Recommended publications
  • The Gran Sasso Underground Laboratory Program
    The Gran Sasso Underground Laboratory Program Eugenio Coccia INFN Gran Sasso and University of Rome “Tor Vergata” [email protected] XXXIII International Meeting on Fundamental Physics Benasque - March 7, 2005 Underground Laboratories Boulby UK Modane France Canfranc Spain INFN Gran Sasso National Laboratory LNGSLNGS ROME QuickTime™ and a Photo - JPEG decompressor are needed to see this picture. L’AQUILA Tunnel of 10.4 km TERAMO In 1979 A. Zichichi proposed to the Parliament the project of a large underground laboratory close to the Gran Sasso highway tunnel, then under construction In 1982 the Parliament approved the construction, finished in 1987 In 1989 the first experiment, MACRO, started taking data LABORATORI NAZIONALI DEL GRAN SASSO - INFN Largest underground laboratory for astroparticle physics 1400 m rock coverage cosmic µ reduction= 10–6 (1 /m2 h) underground area: 18 000 m2 external facilities Research lines easy access • Neutrino physics 756 scientists from 25 countries Permanent staff = 66 positions (mass, oscillations, stellar physics) • Dark matter • Nuclear reactions of astrophysics interest • Gravitational waves • Geophysics • Biology LNGS Users Foreigners: 356 from 24 countries Italians: 364 Permanent Staff: 64 people Administration Public relationships support Secretariats (visa, work permissions) Outreach Environmental issues Prevention, safety, security External facilities General, safety, electrical plants Civil works Chemistry Cryogenics Mechanical shop Electronics Computing and networks Offices Assembly halls Lab
    [Show full text]
  • Required Sensitivity to Search the Neutrinoless Double Beta Decay in 124Sn
    Required sensitivity to search the neutrinoless double beta decay in 124Sn Manoj Kumar Singh,1;2∗ Lakhwinder Singh,1;2 Vivek Sharma,1;2 Manoj Kumar Singh,1 Abhishek Kumar,1 Akash Pandey,1 Venktesh Singh,1∗ Henry Tsz-King Wong2 1 Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221005, India. 2 Institute of Physics, Academia Sinica, Taipei 11529, Taiwan. E-mail: ∗ [email protected] E-mail: ∗ [email protected] Abstract. The INdias TIN (TIN.TIN) detector is under development in the search for neutrinoless double-β decay (0νββ) using 90% enriched 124Sn isotope as the target mass. This detector will be housed in the upcoming underground facility of the India based Neutrino Observatory. We present the most important experimental parameters that would be used in the study of required sensitivity for the TIN.TIN experiment to probe the neutrino mass hierarchy. The sensitivity of the TIN.TIN detector in the presence of sole two neutrino double-β decay (2νββ) decay background is studied at various energy resolutions. The most optimistic and pessimistic scenario to probe the neutrino mass hierarchy at 3σ sensitivity level and 90% C.L. is also discussed. Keywords: Double Beta Decay, Nuclear Matrix Element, Neutrino Mass Hierarchy. arXiv:1802.04484v2 [hep-ph] 25 Oct 2018 PACS numbers: 12.60.Fr, 11.15.Ex, 23.40-s, 14.60.Pq Required sensitivity to search the neutrinoless double beta decay in 124Sn 2 1. Introduction Neutrinoless double-β decay (0νββ) is an interesting venue to look for the most important question whether neutrinos have Majorana or Dirac nature.
    [Show full text]
  • Nuclear Physics
    Nuclear Physics Overview One of the enduring mysteries of the universe is the nature of matter—what are its basic constituents and how do they interact to form the properties we observe? The largest contribution by far to the mass of the visible matter we are familiar with comes from protons and heavier nuclei. The mission of the Nuclear Physics (NP) program is to discover, explore, and understand all forms of nuclear matter. Although the fundamental particles that compose nuclear matter—quarks and gluons—are themselves relatively well understood, exactly how they interact and combine to form the different types of matter observed in the universe today and during its evolution remains largely unknown. Nuclear physicists seek to understand not just the familiar forms of matter we see around us, but also exotic forms such as those that existed in the first moments after the Big Bang and that exist today inside neutron stars, and to understand why matter takes on the specific forms now observed in nature. Nuclear physics addresses three broad, yet tightly interrelated, scientific thrusts: Quantum Chromodynamics (QCD); Nuclei and Nuclear Astrophysics; and Fundamental Symmetries: . QCD seeks to develop a complete understanding of how the fundamental particles that compose nuclear matter, the quarks and gluons, assemble themselves into composite nuclear particles such as protons and neutrons, how nuclear forces arise between these composite particles that lead to nuclei, and how novel forms of bulk, strongly interacting matter behave, such as the quark-gluon plasma that formed in the early universe. Nuclei and Nuclear Astrophysics seeks to understand how protons and neutrons combine to form atomic nuclei, including some now being observed for the first time, and how these nuclei have arisen during the 13.8 billion years since the birth of the cosmos.
    [Show full text]
  • THE BOREXINO IMPACT in the GLOBAL ANALYSIS of NEUTRINO DATA Settore Scientifico Disciplinare FIS/04
    UNIVERSITA’ DEGLI STUDI DI MILANO DIPARTIMENTO DI FISICA SCUOLA DI DOTTORATO IN FISICA, ASTROFISICA E FISICA APPLICATA CICLO XXIV THE BOREXINO IMPACT IN THE GLOBAL ANALYSIS OF NEUTRINO DATA Settore Scientifico Disciplinare FIS/04 Tesi di Dottorato di: Alessandra Carlotta Re Tutore: Prof.ssa Emanuela Meroni Coordinatore: Prof. Marco Bersanelli Anno Accademico 2010-2011 Contents Introduction1 1 Neutrino Physics3 1.1 Neutrinos in the Standard Model . .4 1.2 Massive neutrinos . .7 1.3 Solar Neutrinos . .8 1.3.1 pp chain . .9 1.3.2 CNO chain . 13 1.3.3 The Standard Solar Model . 13 1.4 Other sources of neutrinos . 17 1.5 Neutrino Oscillation . 18 1.5.1 Vacuum oscillations . 20 1.5.2 Matter-enhanced oscillations . 22 1.5.3 The MSW effect for solar neutrinos . 26 1.6 Solar neutrino experiments . 28 1.7 Reactor neutrino experiments . 33 1.8 The global analysis of neutrino data . 34 2 The Borexino experiment 37 2.1 The LNGS underground laboratory . 38 2.2 The detector design . 40 2.3 Signal processing and Data Acquisition System . 44 2.4 Calibration and monitoring . 45 2.5 Neutrino detection in Borexino . 47 2.5.1 Neutrino scattering cross-section . 48 2.6 7Be solar neutrino . 48 2.6.1 Seasonal variations . 50 2.7 Radioactive backgrounds in Borexino . 51 I CONTENTS 2.7.1 External backgrounds . 53 2.7.2 Internal backgrounds . 54 2.8 Physics goals and achieved results . 57 2.8.1 7Be solar neutrino flux measurement . 57 2.8.2 The day-night asymmetry measurement . 58 2.8.3 8B neutrino flux measurement .
    [Show full text]
  • RES-NOVA Sensitivity to Core-Collapse and Failed Core-Collapse Supernova Neutrinos
    Prepared for submission to JCAP RES-NOVA sensitivity to core-collapse and failed core-collapse supernova neutrinos L. Pattavinaa;b;1 N. Ferreiro Iachellinic;1 L. Pagnaninia;d L. Canonicac E. Celib;d M. Clemenzae F. Ferronid;f E. Fiorinie A. Garaic L. Gironie M. Mancusoc S. Nisia F. Petriccac S. Pirroa S. Pozzie A. Puiua;d J. Rotheb S. Schönertb L. Shtembaric R. Straussb V. Wagnerb aINFN Laboratori Nazionali del Gran Sasso, 67100 Assergi, Italy bPhysik-Department and Excellence Cluster Origins, Technische Universität München, 85747 Garching, Germany arXiv:2103.08672v2 [astro-ph.IM] 16 Aug 2021 cMax-Planck-Institut für Physik, 80805 München, Germany dGran Sasso Science Institute, 67100, L’Aquila, Italy eINFN Sezione Milano - Bicocca and Dipartimento di Fisica, Università di Milano - Bicocca, 20126 Milano, Italy f INFN Sezione di Roma1, 00185, Roma, Italy 1Corresponding authors. E-mail: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], ettore.fi[email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected] Abstract. RES-NOVA is a new proposed experiment for the investigation of astrophysical neutrino sources with archaeological Pb-based cryogenic detectors. RES-NOVA will exploit Coherent Elastic neutrino-Nucleus Scattering (CEνNS) as detection channel, thus it will be equally sensitive to all neutrino flavors produced by Supernovae (SNe).
    [Show full text]
  • Full TIPP 2011 Program Book
    Second International Conference on Technology and Instrumentation in Particle Physics June 9-14, 2011 Program & Abstracts Sheraton Chicago Hotel and Towers, Chicago IL ii TIPP 2011 — June 9-14, 2011 Table of Contents Acknowledgements .................................................................................................................................... v Session Conveners ...................................................................................................................................vii Session Chairs .......................................................................................................................................... ix Agenda ....................................................................................................................................................... 1 Abstracts .................................................................................................................................................. 35 Poster Abstracts ..................................................................................................................................... 197 Abstract Index ........................................................................................................................................ 231 Poster Index ........................................................................................................................................... 247 Author List .............................................................................................................................................
    [Show full text]
  • Status and Outlook of the CUORE and CUPID Experimental Calorimetry Programs: an Overview
    Status and Outlook of the CUORE and CUPID Experimental Calorimetry Programs: An Overview Danielle H. Speller for the CUORE and CUPID Collaborations Johns Hopkins University August 5, 2020 Slides provided by CUORE, CUPID, CUPID‐Mo, and Acknowledgements CUPID‐0 Collaborations 8/5/2020 Danielle H. Speller (JHU), CUORE/CUPID, Snowmass Neutrino Workshop 2 Searching for Neutrinoless Double‐Beta Decay with CUORE CUORE: The Cryogenic Underground Observatory for Rare Events • The first tonne‐scale 0νββ experiment operating with thermal detectors • Main objective: 0νββ in 130Te 3 • 988 TeO2 crystals, 5×5×5 cm each • Total mass: 742 kg TeO2 • 130Te mass: 206 kg (all natural abundance) • Macrocalorimeter operation in ~10 mK cryostat Heat bath ~10 mK Thermistor (NTD-Ge) • Located underground at LNGS (Italy) (Copper) • Expected energy resolution at 2615 keV: 5 keV Absorber Crystal (TeO2) FWHM • Background goal: 0.01 cts/(keV∙kg ∙yr) at Qββ 0ν 25 • Sensitivity: T1/2 = 9×10 yr (90% C.I.) in 5 Energy Cryogenics 102, 9‐21 (2019). Thermal coupling release arxiv:1904.05745 years of data collection (Eur. Phys. J. C (2017) (PTFE) Cryogenics 93, 56‐65 (2018). 77:532) arxiv:1712.02753 Danielle H. Speller (JHU), CUORE/CUPID, Snowmass Neutrino 8/5/2020 3 Workshop • Total analyzed exposure: region of interest Recent Results: Improved 372.5 kg∙yr • Median exclusion sensitivity: • Resolution (expo.‐weighted 1.7 x 1025 yr 130 harmonic avg, Qββ): 7.0±0.4 0ν 25 • T1/2 > 3.2 x 10 yr (90% C.I.) Limit on 0νββ in Te with keV Bayesian lower limit on 130Te • Background: 1.38±0.07 x 10‐2 half‐life CUORE (2020) cts/(keV∙kg∙yr) in the 0νββ Phys.
    [Show full text]
  • Neutrinoless Double Beta Decay Searches
    FLASY2019: 8th Workshop on Flavor Symmetries and Consequences in 2016 Symmetry Magazine Accelerators and Cosmology Neutrinoless Double Beta Decay Ke Han (韩柯) Shanghai Jiao Tong University Searches: Status and Prospects 07/18, 2019 Outline .General considerations for NLDBD experiments .Current status and plans for NLDBD searches worldwide .Opportunities at CJPL-II NLDBD proposals in China PandaX series experiments for NLDBD of 136Xe 07/22/19 KE HAN (SJTU), FLASY2019 2 Majorana neutrino and NLDBD From Physics World 1935, Goeppert-Mayer 1937, Majorana 1939, Furry Two-Neutrino double beta decay Majorana Neutrino Neutrinoless double beta decay NLDBD 1930, Pauli 1933, Fermi + 2 + (2 ) Idea of neutrino Beta decay theory 136 136 − 07/22/19 54 → KE56 HAN (SJTU), FLASY2019 3 ̅ NLDBD probes the nature of neutrinos . Majorana or Dirac . Lepton number violation . Measures effective Majorana mass: relate 0νββ to the neutrino oscillation physics Normal Inverted Phase space factor Current Experiments Nuclear matrix element Effective Majorana neutrino mass: 07/22/19 KE HAN (SJTU), FLASY2019 4 Detection of double beta decay . Examples: . Measure energies of emitted electrons + 2 + (2 ) . Electron tracks are a huge plus 136 136 − 54 → 56 + 2 + (2)̅ . Daughter nuclei identification 130 130 − 52 → 54 ̅ 2νββ 0νββ T-REX: arXiv:1512.07926 Sum of two electrons energy Simulated track of 0νββ in high pressure Xe 07/22/19 KE HAN (SJTU), FLASY2019 5 Impressive experimental progress . ~100 kg of isotopes . ~100-person collaborations . Deep underground . Shielding + clean detector 1E+27 1E+25 1E+23 1E+21 life limit (year) life - 1E+19 half 1E+17 Sn Ca νββ Ge Te 0 1E+15 Xe 1E+13 1940 1950 1960 1970 1980 1990 2000 2010 2020 Year .
    [Show full text]
  • The World Underground Scientific Facilities a Compendium
    A. Bettini G. Galilei Physics Department. Padua University INFN. Padua Canfranc Underground Laboratory [email protected] THE WORLD UNDERGROUND SCIENTIFIC FACILITIES A COMPENDIUM Abstract. Underground laboratories provide the low radioactive background environment necessary to explore the highest energy scales that cannot be reached with accelerators, by searching for extremely rare phenomena. I have requested to the Directors of the Laboratories a standard set of questions on the principal characteristics of their laboratory and collected them in this compendium. I included the ideas and plans for short-range developments. However, next-generation structures, such as those for megaton-size detectors, are not discussed. A short version of this work will be published in the Proccedings of TAUP 2007. 1 2 PREFACE . 4 EUROPE...................................................................................................................................... 6 BNO. BAKSAN NEUTRINO OBSERVATORY (RUSSIA)............................................................................ 6 BUL. BOULBY PALMER LABORATORY (UK)....................................................................................... 9 CUPP. CENTRE FOR UNDERGROUND PHYSICS AT PYHÄSALMI (FINLAND)............................................ 11 LNGS. LABORATORI NAZIONALI DEL GRAN SASSO. L’AQUILA (ITALY) ............................................... 13 LSC. LABORATORIO SUBTERRÁNEO DE CANFRANC (SPAIN).............................................................. 16 LSM. LABORATOIRE
    [Show full text]
  • The Start up of the CUORE Experiment at LNGS CUORE
    The start up of the CUORE experiment at LNGS CUORE Photo credit: Yury Suvorov Antonio Branca @ INFN Padova On behalf of the CUORE Collaboration WIN2017 @ UC Irvine – 19-24 June 2017 Double beta decay (DBD) CUORE 2ν DBD: (A, Z) → (A, Z + 2)+ 2e− + 2ν 0ν DBD: (A, Z) → (A, Z + 2)+ 2e− - proposed in 1935 by - proposed in 1937 by Maria Goeppert-Mayer; Eore Majorana; - 2nd order process allowed - requires pHysics beyond in the Standard Model; Standard Model; τ ~ 1019−21 yr τ >1024−25 yr Energy spectrum of the two electrons in DBD 0ν DBD Signature: monocHromac line in the energy spectrum at the energy value smeared by detector resoluOon! 19-24 June 2017 A. Branca - WIN2017 @ UCI 2 Double beta decay (DBD) II CUORE EffecOve Majorana mass m = f (Δm , Δm , m ,α ,α ,δ) THe 0ν DBD Half-life: ββ 1,2 2,3 1 1 2 2 0⌫ 1 0⌫ 0⌫ 2 mββ (T1/2)− = G (Q, Z) M |h 2 i| | | me PHase space 5 Nuclear Matrix Element factor ~Q ßß (theoreOcal uncertainty ~2-3) (accurately calculable) ISM | 9 IBM ν 0 QRPA-T |M 8 QRPA-J Physics consequences if 0ν DBD is observed: PHFB GCM 7 6 • proof of the Majorana nature of neutrino; 5 • constrain on the neutrino mass HierarcHy and scale; 4 3 • lepton number violaon (ΔL = 2): a possible source 2 of maer-anOmaer asymmetry in the universe; 1 0 48Ca 76Ge 82Se 96Zr 100Mo 116Cd 124Sn 128Te 130Te 130Xe 150Nd 19-24 June 2017 A. Branca - WIN2017 @ UCI 3 Sensitivity CUORE Half-life corresponding to the minimum number of detectable signal events above background at a given C.L.
    [Show full text]
  • Tracking Ghost Particles High Performance Computing for the Icecube Neutrino Observatory
    Tracking Ghost Particles high performance computing for the IceCube Neutrino Observatory Tyce DeYoung Department of Physics and Astronomy Michigan State University Outline • Neutrinos and the IceCube Neutrino Observatory • Tracking Neutrinos Through Ice • Tracking Neutrinos Through the Earth 2 Tyce DeYoung Neutrinos – Nature’s “Ghost Particles” • Neutrinos are fundamental particles, but very strange • A million times lighter than any other known particle • Barely interact with other matter • “Oscillate” between the three different types – an electron neutrino will spontaneously change into a tau neutrino 4 Tyce DeYoung The Science of IceCube I NTERNATIONAL JOURNAL OF HIGH-ENERGY PHYSICS CERNCOURIER WELCOME V OLUME 54 NUMBER 10 D ECEMBER 2014 • Learning about our Universe CERN Courier – digital edition Welcome to the digital edition of the December 2014 issue of CERN Courier. 4HE%UROPEAN0HYSICAL*OURNAL#As CERN’s 60th-anniversary year comes to an end, CERN Courier gives a voice to some of the organization’s4HE%UROPEAN0HYSICAL*OURNAL pioneers who are no longer with us. WPMVNFrOVNCFSrKVMZr Extracts from audio recordings5IF&VSPQFBO1IZTJDBM+PVSOBM$ in CERN’s archives bring to life the spirit WPMVNFrOVNCFSrKVMZrof adventure of the early CERN. One of the studies that CERN pioneered • The Earth is constantly bombarded was the measurement of the “g-2” parameter of the muon – an experiment that in its latest incarnation is setting up in Fermilab. The year also saw the 50th anniversary of the International Centre for Theoretical Physics in Trieste, and an interview with the centre’s%0* current director reveals interesting# 3FDPHOJ[FECZ&VSPQFBO1IZTJDBM4PDJFUZ "*!7ATT 0-OTYLINSKIAND234HORNE -3HARIFAND23ALEEM similarities and contrasts between the two organizations. The end of the year 5IFFõFDUPG-)$KFUEBUBPO.4581%'T 4UVEZPGJOnBUJPOBSZHFOFSBMJ[FEDPTNJD also offers the traditional seasonal Bookshelf.
    [Show full text]
  • Particle Detectors for Non-Accelerator Physics
    29. Detectors for non-accelerator physics 1 Written 2009 (see the various sections for authors). 29. PARTICLE DETECTORS FOR NON-ACCEL. PHYSICS . 1 29.1.Introduction........................... 1 29.2. High-energy cosmic-ray hadron and gamma-ray detectors . 2 29.2.1.Atmosphericfluorescencedetectors............... 2 29.2.2. Atmospheric Cherenkov telescopes for high-energy γ- rayastronomy.......................... 4 29.3.Largeneutrinodetectors...................... 6 29.3.1.Deepliquiddetectorsforrareprocesses.............. 6 29.3.1.1. Liquid scintillator detectors . 8 29.3.1.2.WaterCherenkovdetectors................. 9 29.3.2.Neutrinotelescopes...................... 11 29.4. Large time-projection chambers for rare event detection . 16 29.5. Sub-Kelvin detectors . 20 29.5.1.ThermalPhonons....................... 21 29.5.2. Athermal Phonons and Superconducting Quasiparticles . 24 29.5.3. Ionization and Scintillation . 25 29.6.Low-radioactivitybackgroundtechniques............... 26 29.6.1.Definingtheproblem...................... 26 29.6.2.Environmentalradioactivity.................. 27 29.6.3. Radioimpurities in detector or shielding components . 28 29.6.4.Radonanditsprogeny..................... 29 29.6.5.Cosmicrays......................... 30 29.6.6.Neutrons........................... 30 29. PARTICLE DETECTORS FOR NON-ACCELERATOR PHYSICS 29.1. Introduction Non-accelerator experiments have become increasingly important in particle physics. These include classical cosmic ray experiments, neutrino oscillation measurements, and searches for double-beta
    [Show full text]