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arXiv · 2111.01053

Complementarity between neutrinoless double beta decay and collider searches for heavy neutrinos in composite-fermion models

S. Biondini·S. Dell'Oro·R. Leonardi·S. Marcocci·O. Panella·M. Presilla·F. Vissani
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Abstract

Composite-fermion models predict excited quarks and leptons with mass scales which can potentially be observed at high-energy colliders like the LHC; the most recent exclusion limits from the CMS and ATLAS Collaborations corner excited-fermion masses and the compositeness scale to the multi-TeV range. At the same time, hypothetical composite Majorana neutrinos would lead to observable effects in neutrinoless double beta decay ($0\nu \beta \beta$) experiments. In this work, we show that the current composite-neutrino exclusion limit $M_N>4.6$ TeV, as extracted from direct searches at the LHC, can indeed be further improved to $M_N>8.8$ TeV by including the bound on the nuclear transition $^{136}$Xe $\to$ $^{136}$Ba $+2e^-$. Looking ahead, the forthcoming HL-LHC will allow probing a larger portion of the parameter-space, nevertheless, it will still benefit from the complementary limit provided by $0 \nu \beta \beta$ future detectors to explore composite-neutrino masses up to $12.6$ TeV.

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S. Biondini, S. Dell'Oro, R. Leonardi, S. Marcocci, O. Panella, M. Presilla, F. Vissani. 2021-11-01. Complementarity between neutrinoless double beta decay and collider searches for heavy neutrinos in composite-fermion models. https://arxiv.org/abs/2111.01053

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