Sch nert , T AUP 2009 !e - ! First results of the search of neutrinoless double beta decay with the NEMO 3 detector, R. Arnold et al. Researchers are waiting for a double-beta decay to occur inside the Majorana. Overview Experimental groups worldwide are working to develop detectors that may allow the observation of neutrinoless double-beta decay. (N 2;Z+ 2) + e + e . Neutrinoless double beta decay: lt;p|>|Double beta decay| is a radioactive decay process where a nucleus releases two |beta rays|... World Heritage Encyclopedia, the aggregation of the largest online encyclopedias available, and the most definitive collection ever assembled. L d L u L! Lett. First evidence for neutrinoless double beta decay is observed giving first evidence for lepton number violation. Neutrinoless double beta decay, 0 , presents the best and perhaps the only, way to detect Majorana neutrinos. In Figure 4 are the few isotopes that can even undergo the decay. neutrinoless double beta decay, even if neutrinos are in-deed Majorana particles and the inverted hierarchy is realized. DNP Newport News 24 October 2013 Freija Descamps, 0!"" Figure 4: A table of isotopes that can undergo neutrinoless double beta decay. Neutrinoless Double Beta Decay Neutrinoless double beta decay is really a special situation of beta decay. Recently it has been developed as a promising candidate for loading in liquid scintillator to explore the Majorana or Dirac nature of the neutrino through a search for neutrinoless double beta decay (0νββ). Observations in more than one isotope will only make things better. SNOLAB Fig. Neutrinoless double beta decay with SNO+ Freija Descamps for the SNO+ collaboration - 0!"" It might also be the only practical process that allows one to test whether neutrinos are Majorana particles. tory, searches for neutrinoless double beta decay. Neutrinoless double beta decay (0νββ) is a very slow lepton-number-violating nuclear transition that occurs if neutrinos have mass (and oscillation experiments tell us they do), and are their own antiparticles, i.e. S . [3] The one isotope not on this list is argon, which means a di erent one would have to be used. Neutrinoless Double Beta Decay is mediated by light and massive Majorana neutrinos (the ones which oscillate) and all other mechanisms potentially leading to 0νββ give negligible or no contribution W νi νi W dL dL uL e− L e− L uL Uei q Uei prediction of (100 −ǫ)% of all neutrino mass mechanisms (lecture by Andre De Gouvea) 13 Wilkerson Primakoff Lecture: Neutrinoless Double-Beta Decay April APS Meeting 2007 A, Z+2 A, Z+3 A, Z+1 A, Z A, Z-1 ββ 0+ 0+ Double-Beta Decay In a number of even-even nuclei, β-decay is energetically forbidden, while double-beta decay, from a nucleus of Fig. The evidence for this decay mode is 97% (2.2σ) with the Bayesian method, and 99.8% c.l. Several radioactive isotopes produce decays in the signal region of interest. Currently, experimental efforts are gearing up for the so-called "tonne-phase" searches, with sensitivity reach of T_1/2 ~ 10^28 years. For many isotopes like 76Ge decay is energetically forbidden, but double beta decay (2 ) is allowed (A;Z) ! 3 ... Signature of neutrinoless double beta decay 5 With SNO+ ... Short and long living isotopes can be produced by cosmogenic activation of natural S . Moreover, the oscillation results do not tell us anything about the prop-erties of neutrinos under charge conjugation. Majorana particles. Tellurium-130 has the highest natural abundance of any double-beta decay isotopes. 95 (2005) 182302, arXiv:hep-ex/0507083. with SNO+ - Backgrounds - Schedule 1. Figure 2: Neutrinoless double beta decay mediated by the standard mechanism, the virtual exchange of a light Majorana neutrino. In the case of the 2nbb-decay mode, the spectrum is continuous, extending from 0 to Qbb and peaking below Qbb=2. These include the observation of neutrinoless double beta decay in multiple isotopes [45, 70–72], or measuring the decay distribution, for example in the SuperNEMO experiment . So far, no discovery. (A;Z+ 2) + 2e + 2 e (1) This was suggested very early [1] and - following the idea of Majorana that neutrinos could be their own anti-particle [2] - also the possibility of neutrinoless double beta decay 0 … Neutrinoless double-beta decay is a forbidden, lepton-number-violating nuclear transition whose observation would have fundamental implications for neutrino physics, theories beyond the Standard Model, and cosmology. clei. 130Te !130Xe + 2e- signature Column 7 of Table 1 represents the computed half-lives for neutrinoless double beta decay of various isotopes and is compared with the experimental values given in … • observation in multiple isotopes may help reveal the nature of the lepton number violating process(es). The experiment has been taking data since 2003 with seven double beta isotopes and completed data acquisition in January 2011. The double beta decay experiment NEMO-3 has compleated data taking in January 2011. These experiments push the trade-o between having a large mass of available isotope but lower energy resolution into a new regime. Theory of neutrinoless double beta decay J D Vergados1,2, H Ejiri3,4 and F ˇSimkovic 5,6 1Theoretical Physics Division, University of Ioannina, GR–451 10, Ioannina, ... reaction are searched in a suﬃcient number of nuclear isotopes. The study showed that if neutrinoless double-beta decay happens, it must do so with a half-life of at least 1. 55 Among the isotopes produced by cosmogenic activation, only the ones with a Q-value higher that the Q-value of the neutrinoless double beta decay would contribute to the background in the ROI, so isotopes with higher $$0\nu \beta \beta$$ Q-value are favored in this respect. Neutrinoless double beta decay is discovery science - if we ﬁnd it - we ﬁnd new physics no matter what! By demonstrating that it is possible to isolate germanium-based searches from environmental interference, GERDA improved upon the sensitivity of previous efforts by an order of magnitude. Tonne-scale experiments will improve current sensitivity by 100x We need more than one isotopic experiment for discovery Lots of technologies are being used to get us to this ground-breaking science. L e! Neutrinoles double beta decay is the only process known so far able to test the neutrino intrinsic nature: its experimental observation would imply that the lepton number is violated by two units and prove that neutrinos have a Majorana mass components, being their own anti-particle. Majorana neutrinos) so the same neutrino can … decay and predictions from oscillation experiments ¥!Comparison of DBD isotopes ¥!Challenges & experimental approaches ¥!Overview experimental projects ¥!Outlook . Neutrino-less double beta decay is the most sensitive probe of lepton number violation and a powerful tool to study the origin of neutrino masses. The present empirical formula is applied for all the observed neutrinoless double beta decay isotopes. Phenomenology of Neutrinoless Double Beta Decay J.J. Gómez-Cadenas d L u L W W e! Feynman diagram of neutrinoless double beta decay, with two neutrons decaying to two protons. Sch nert , T AUP 2009 Outline ¥!0 !"" It is the double beta decay without neutrino emission, or neutrinoless double beta decay (). (3.1σ) with the method recommended by the Particle Data Group. Measuring event rate at the expected energy. Beta decay is a very common type of nuclear decay which takes place when a neutron within an unstable nucleus emits an electron as well as an antineutrino and turns into a proton. And the pace of theoretical work will increase dramatically if the decay is seen. In the ﬁrst case, the corresponding diagram involves two vertices which are both point-like at the Fermi scale, … Rev. Neutrinoless double beta decay is a unique signature of Majorana nature of neutrinos. JUNO and Neutrinoless Double Beta Decay Shao-FengGe∗1 andWernerRodejohann†1 1Max-Planck-Institut fu¨r Kernphysik, Postfach 103980, 69029 Heidelberg, Germany April29,2019 Abstract We study the impact of the precision determination of oscillation parameters in the JUNO experiment on half-life predictions for neutrinoless double beta decay. If it does, and if neutrinos can indeed act like their own antiparticle, then the two neutrinos necessary may interact, possibly being absorbed, making the double-beta decay seem neutrinoless. 1 shows the process and the experimentally required nuclear level scheme for the transition (N;Z) ! This process assumes a simple form; namely, The Feynman diagram of the process, written in terms of the particles we know today and of massive Majorana neutrinos, is given Figure 1 . 8 × 1 0 2 6 years. Neutrinoless Double Beta Decay Stefan Sch nert Max-Planck-Institut f r Kernphysik Heidelberg . 7: Electron energy spectrum. 2 Neutrinoless double beta decay 2.1 Effective description Contributions to 0νββ decay can be categorised as either long-range or short-range interactions. Neutrinoless double beta decay violates lepton number and the experimental programs are therefore on equal footing to proton‐decay searches. The motivation for several large efforts in this field is therefore obvious. • The signature for this process is a peak at the end-point of the two-neutrino double beta decay (2νββ) spectrum. Neutrinoless Double Beta Decay (0νDBD) Low-Tc TES at Argonne 3 4/13/15 • Two simultaneous electrons with summed kinetic energy Qββ ~2.527 Mev. neutrinos is to see the neutrinoless double beta decay (0νββ) process. (NEMO), Phys. The use of the world’s largest liquid scintillator detectors in the search for neutrinoless double beta decay is a promising development that has come to the fore in the last few years [1, 2]. Neutrinoless Double Beta Decay • 2νββ • Standard Model process • Emits two neutrinos which carry away energy • 0νββ • Violates lepton number • Signal at the Q-value of the decay with width of σ E • Candidate isotopes: 48Ca, 76Ge, 82Se, 96Zr, 100Mo, 116Cd, 128Te, 130Te, 136Xe, 150Nd Observed, but rare " (T½ > 1019 yr) Only visible in nuclei for " J.F. Our opin-ion is that the uncertainty in the nuclear matrix elements The only emitted products in this process are two electrons, which can occur if the neutrino and antineutrino are the same particle (i.e. • origins for ν mass and the LNV process(es) can be extracted with reliance on both nuclear and particle theory. the neutrinoless double beta decay, reviewed here, will help in foreseeable future in determining, or at least narrowing down, the absolute neutrino mass scale, and in deciding which of these two possibilities is applicable. Neutrinoless Double-beta Decay June 13 - July 14, 2017 Opening workshop June 13 and 14, 2017 Closing workshop July 13 and 14, 2017. • In inverted hierarchy, Majorana neutrino mass >= 10 meV. Signature: peak in the sum of the kinetic energies of the two electrons. Neutrino emission, or neutrinoless double beta decay 5 Phenomenology of neutrinoless double decay. Large mass of available isotope but lower energy resolution into a new.... 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