B. Richards

Probing New Physics Models of Neutrinoless Double Beta Decay with SuperNEMO

The possibility to probe new physics scenarios of light Majorana neutrino exchange and right-handed currents at the planned next generation neutrinoless double β decay experiment SuperNEMO is discussed. Its ability to study different isotopes and track the outgoing electrons provides the means to discriminate different underlying mechanisms for the neutrinoless double β decay by measuring the decay half-life and the electron angular and energy distributions.

Search for neutrinoless double-beta decay of

We report the results of a search for the neutrinoless double-β decay (0νββ) of Mo100, using the NEMO-3 detector to reconstruct the full topology of the final state events. With an exposure of 34.7  kg·y, no evidence for the 0νββ signal has been found, yielding a limit for the light Majorana neutrino mass mechanism of T1/2(0νββ)>1.1×1024 years (90% C.L.) once both statistical and systematic uncertainties are taken into account. Depending on the nuclear matrix elements this corresponds to an upper limit on the Majorana effective neutrino mass of ⟨mν⟩<0.3–0.9  eV (90% C.L.). Constraints on other lepton number violating mechanisms of 0νββ decays are also given. Searching for high-energy double electron events in all suitable sources of the detector, no event in the energy region [3.2–10] MeV is observed for an exposure of 47  kg·y.

^{100}Mo

Double beta decay of 100Mo to the excited states of daughter nuclei has been studied using a 600 cm3 low-background HPGe detector and an external source consisting of 2588 g of 97.5% enriched metallic 100Mo, which was formerly inside the NEMO-3 detector and used for the NEMO-3 measurements of 100Mo. The half-life for the two-neutrino double beta decay of 100Mo to the excited View the MathML source01+ state in 100Ru is measured to be T1/2=[7.5±0.6(stat)±0.6(syst)]⋅1020 yrT1/2=[7.5±0.6(stat)±0.6(syst)]⋅1020 yr. For other (0ν+2ν)(0ν+2ν) transitions to the View the MathML source21+, View the MathML source22+, View the MathML source02+, View the MathML source23+ and View the MathML source03+ levels in 100Ru, limits are obtained at the level of ∼(0.25-1.1)⋅1022 yr∼(0.25-1.1)⋅1022 yr.

with the NEMO-3 detector

We report results from the NEMO-3 experiment based on an exposure of 1275 days with 661 g of (130)Te in the form of enriched and natural tellurium foils. The ββ decay rate of (130)Te is found to be greater than zero with a significance of 7.7 standard deviations and the half-life is measured to be T(½)(2ν) = [7.0 ± 0.9(stat) ± 1.1(syst)] × 10(20) yr. This represents the most precise measurement of this half-life yet published and the first real-time observation of this decay.

Investigation of double beta decay of 100Mo to excited states of 100Ru

The development of BiPo detectors is dedicated to the measurement of extremely high radiopurity in

Measurement of the Double Beta Decay Half-life of 130Te with the NEMO-3 Detector

^{208}

Results of the BiPo-1 prototype for radiopurity measurements for the SuperNEMO double beta decay source foils

Tl and

Measurement of the Double-Beta Decay Half-Life and Search for the Neutrinoless Double-Beta Decay of

^{214}

^{48}{\rm Ca}

Bi for the SuperNEMO double beta decay source foils. A modular prototype, called BiPo-1, with 0.8

with the NEMO-3 Detector

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