2019年12月24日
Search for an invisibly decaying $Z^{\prime}$ boson at Belle II in $e^+ e^- \to μ^+ μ^- (e^{\pm} μ^{\mp})$ plus missing energy final states
Theories beyond the standard model often predict the existence of an
additional neutral boson, the $Z^{\prime}$. Using data collected by the Belle
II experiment during 2018 at the SuperKEKB collider, we perform the first
searches for the invisible decay of a $Z^{\prime}$ in the process $e^+ e^- \to
\mu^+ \mu^- Z^{\prime}$ and of a lepton-flavor-violating $Z^{\prime}$ in $e^+
e^- \to e^{\pm} \mu^{\mp} Z^{\prime}$. We do not find any excess of events and
set 90\% credibility level upper limits on the cross sections of these
processes. We translate the former, in the framework of an $L_{\mu}-L_{\tau}$
theory, into upper limits on the $Z^{\prime}$ coupling constant at the level of
$5 \times 10^{-2}$ -- $1$ $M_{Z^\prime}\leq 6$ GeV/$c^2$.
additional neutral boson, the $Z^{\prime}$. Using data collected by the Belle
II experiment during 2018 at the SuperKEKB collider, we perform the first
searches for the invisible decay of a $Z^{\prime}$ in the process $e^+ e^- \to
\mu^+ \mu^- Z^{\prime}$ and of a lepton-flavor-violating $Z^{\prime}$ in $e^+
e^- \to e^{\pm} \mu^{\mp} Z^{\prime}$. We do not find any excess of events and
set 90\% credibility level upper limits on the cross sections of these
processes. We translate the former, in the framework of an $L_{\mu}-L_{\tau}$
theory, into upper limits on the $Z^{\prime}$ coupling constant at the level of
$5 \times 10^{-2}$ -- $1$ $M_{Z^\prime}\leq 6$ GeV/$c^2$.
- リンク情報
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- arXiv
- http://arxiv.org/abs/arXiv:1912.11276
- Arxiv Url
- http://arxiv.org/abs/1912.11276v2
- Arxiv Url
- http://arxiv.org/pdf/1912.11276v2 本文へのリンクあり
- ID情報
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- arXiv ID : arXiv:1912.11276