Review on double beta decay experiments and comparison with theory (original) (raw)

Neutrino-less Double Beta Decay and Physics Beyond the Standard Model

Eprint Arxiv Hep Ph 9509306, 1995

A brief sketch is given of the present observational status and future prospects of the physics of neutrino mass, including a survey of the various theoretical schemes of neutrino mass generation. Emphasis is given to those which are motivated by present experimental hints from solar and atmospheric neutrinos, as well as from cosmological data related to the dark matter question. The conceptual importance of neutrino-less double beta decay as a distinctive signature of the Majorana character of neutrinos is stressed. Barring accidental cancellations this process gives the strongest laboratory constraint on neutrino mass.

Double beta decay, Majorana neutrinos, and neutrino mass

Reviews of Modern Physics, 2008

The theoretical and experimental issues relevant to neutrinoless double beta decay are reviewed. The impact that a direct observation of this exotic process would have on elementary particle physics, nuclear physics, astrophysics, and cosmology is profound. Now that neutrinos are known to have mass and experiments are becoming more sensitive, even the nonobservation of neutrinoless double beta decay will be useful. If the process is actually observed, we will immediately learn much about the neutrino. The status and discovery potential of proposed experiments are reviewed in this context, with significant emphasis on proposals favored by recent panel reviews. The importance of and challenges in the calculation of nuclear matrix elements that govern the decay are considered in detail. The increasing sensitivity of experiments and improvements in nuclear theory make the future exciting for this field at the interface of nuclear and particle physics.

Majorana neutrino masses and neutrino-less double beta decays

Nuclear Physics B - Proceedings Supplements, 2005

The present status and the perspectives of neutrino-less ββ decays and Majorane ν masses are briefly discussed. The effective ν masses to be studied by ββ decays are constrained by ν oscillation data and the cosmological observation. ββ experiments with mass sensitivities of the atmospheric and solar ν masses are very interesting.

Neutrino-less double beta decays and Majorana neutrinos

Hyperfine Interactions, 2011

Neutrino-less double beta decays (0νββ) are sensitive and realistic probes for studying the Majorana nature of neutrinos, the ν mass spectrum and the absolute mass scale, the lepton sector CP and others beyond the standard electro-weak theory. This report reviews briefly 0νββ processes and Majorana neutrinos, the present and future 0νββ experiments and 0νββ nuclear matrix elements.

Double beta decays and neutrino masses

Journal of Physics: Conference Series, 2006

Neutrino-less double beta decays (0), which violate the lepton number conservation law by ÁL ¼ 2, are of great interest for studying the fundamental properties of neutrinos beyond the standard electroweak theory. High-sensitivity 0 studies with mass sensitivities of the solar and atmosphericmasses are crucial for studying the Majorana nature of 's, the mass spectrum, the absolute-mass scale, the Majorana CP phases and other fundamental properties of neutrinos and weak interactions. Actually, high-sensitivity experiments of 0 are the unique and practical method for studying all these fundamental properties of neutrinos in the foreseeable future. On the basis of the recent oscillation studies, the effective mass sensitivity required for observing the 0 rate is of the order of the atmospheric mass scale of m A $ 50 meV in the case of the inverted mass hierarchy and of the order of the solar mass scale of m S $ 8 meV in the case of the normal hierarchy. The present detectors with sensitivities of 150-300 meV are effective in the case of the quasi-degenerate mass spectrum. Future detectors with higher sensitivities of the orders of m Am S , using different nuclei and methods (calorimetric, spectroscopic), are indispensable for establishing 0. Theoretical and experimental studies for evaluating nuclear matrix elements M 0 within 20-30% are important for extracting the sensible mass from the 0 rate. Charge exchange reactions by means of nuclear, electron and probes provide useful data for M 0. International collaboration for experimental and theoretical works are encouraged to perform next-generation experiments. High-sensitivity detectors can be used for studying rare nuclear processes such as solar 's, dark matter, charge nonconservation, and nucleon decays. This report is a brief review of double beta decays and neutrinos with emphasis on highsensitivity 0 studies for the Majorana mass.

The contribution of light Majorana neutrinos to neutrinoless double beta decay and cosmology

Journal of Cosmology and Astroparticle Physics, 2015

Cosmology is making impressive progress and it is producing stringent bounds on the sum of the neutrino masses Σ, a parameter of great importance for the current laboratory experiments. In this letter, we exploit the potential relevance of the analysis of Palanque-Delabrouille et al. [JCAP 1502[JCAP , 045 (2015] to the neutrinoless double beta decay (0νββ) search. This analysis indicates small values for the lightest neutrino mass, since the authors find Σ < 84 meV at 1σ C. L., and provides a 1σ preference for the normal hierarchy. The allowed values for the Majorana effective mass, probed by 0νββ, turn out to be < 75 meV at 3σ C. L. and lower down to less than 20 meV at 1σ C. L. . If this indication is confirmed, the impact on the 0νββ experiments will be tremendous since the possibility of detecting a signal will be out of the reach of the next generation of experiments.

Neutrinoless Double-Beta Decay: A Roadmap for Matching Theory to Experiment

arXiv (Cornell University), 2022

The observation of neutrino oscillations and hence non-zero neutrino masses provided a milestone in the search for physics beyond the Standard Model. But even though we now know that neutrinos are massive, the nature of neutrino masses, i.e., whether they are Dirac or Majorana, remains an open question. A smoking-gun signature of Majorana neutrinos is the observation of neutrinoless double-beta decay, a process that violates the lepton-number conservation of the Standard Model. This white paper focuses on the theoretical aspects of the neutrinoless double-beta decay program and lays out a roadmap for future developments. The roadmap is a multi-scale path starting from high-energy models of neutrinoless double-beta decay all the way to the low-energy nuclear many-body problem that needs to be solved to supplement measurements of the decay rate. The path goes through a systematic effective-field-theory description of the underlying processes at various scales and needs to be supplemented by lattice quantum chromodynamics input. The white paper also discusses the interplay between neutrinoless double-beta decay, experiments at the Large Hadron Collider and results from astrophysics and cosmology in probing simplified models of lepton-number violation at the TeV scale, and the generation of the matter-antimatter asymmetry via leptogenesis. This white paper is prepared for the topical groups TF11 (Theory of Neutrino Physics), TF05 (Lattice Gauge Theory), RF04 (Baryon and Lepton Number Violating Processes), NF03 (Beyond the Standard Model) and NF05

Neutrinoless double beta decay: Experimental challenges

Proceedings of Neutrino Oscillation Workshop — PoS(NOW2018)

The evidence for neutrino flavor oscillations has convincingly shown that neutrino has a finite mass. However, the fundamental question whether neutrino is Majorana or Dirac particle is still unanswered. The only known practical way to probe the Majorana nature of neutrinos experimentally is via the discovery of the neutrinoless double beta (0νβ β) decay. Moreover, this process violates lepton number conservation. Hence, it is forbidden within the Standard Model of particle physics and, therefore, the discovery of 0νβ β decay will confirm the existence of New Physics. That is the reason why during decades, this search remains worldwide ranked amongst the top research priorities. Many 0νβ β experiments with a target mass around hundred kg are ongoing and several of next-generation tonne-scale projects are being prepared. The status of some of them is reviewed.

Neutrinoless double beta decay and heavy sterile neutrinos

Nuclear Physics B, 2012

The experimental rate of neutrinoless double beta decay can be saturated by the exchange of virtual sterile neutrinos, that mix with the ordinary neutrinos and are heavier than 200 MeV. Interestingly, this hypothesis is subject only to marginal experimental constraints, because of the new nuclear matrix elements. This possibility is analyzed in the context of the Type I seesaw model, performing also exploratory investigations of the implications for heavy neutrino mass spectra, rare decays of mesons, LHC, and lepton flavor violation. The heavy sterile neutrinos can saturate the rate only when their masses are below some 10 TeV, but in this case, the suppression of the light-neutrino masses has to be more than the ratio of the electroweak scale and the heavy-neutrino scale; i.e., more suppressed than the naive seesaw expectation. We classify the cases when this condition holds true in the minimal version of the seesaw model, showing its compatibility (1) with neutrinoless double beta rate being dominated by heavy neutrinos and (2) with any light neutrino mass spectra. The absence of excessive finetunings and the radiative stability of light neutrino mass matrices, together with a saturating sterile neutrino contribution, imply an upper bound on the heavy neutrino masses of about 10 GeV. We extend our analysis to the Extended seesaw scenario, where the light and the heavy sterile neutrino contributions are completely decoupled, allowing the sterile neutrinos to saturate the present experimental bound on neutrinoless double beta decay. In the models analyzed, the rate of this process is not strictly connected with the values of the light neutrino masses, and a fast transition rate is compatible with neutrinos lighter than 100 meV. * of lepton number violation, or in other terms, as potential additional contributors to 0ν2β. The main goal of the present paper is a systematic study of this possibility, considered occasionally in the past . Note incidentally that the possibility that the heavy neutrinos are not ultra-heavy, and thus can be potentially tested experimentally, is the first one that has been considered in . 2