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arXiv · 1809.10511

Light-Neutrino Exchange and Long-Distance Contributions to $0\nu2β$ Decays: An Exploratory Study on $ππ\to ee$

Xu Feng·Lu-Chang Jin·Xin-Yu Tuo·Shi-Cheng Xia
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Abstract

We present an exploratory lattice QCD calculation of the neutrinoless double beta decay $ππ\to ee$. Under the mechanism of light-neutrino exchange, the decay amplitude involves significant long-distance contributions. The calculation reported here, with pion masses $m_π=420$ and 140 MeV, demonstrates that the decay amplitude can be computed from first principles using lattice methods. At unphysical and physical pion masses, we obtain that amplitudes are $24\%$ and $9\%$ smaller than the predication from leading order chiral perturbation theory. Our findings provide the lattice QCD inputs and constraints for effective field theory. A follow-on calculation with fully controlled systematic errors will be possible with adequate computational resources.

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Xu Feng, Lu-Chang Jin, Xin-Yu Tuo, Shi-Cheng Xia. 2019-01-09. Light-Neutrino Exchange and Long-Distance Contributions to $0\nu2β$ Decays: An Exploratory Study on $ππ\to ee$. https://doi.org/10.1103/physrevlett.122.022001

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