Neutrino Floor in Leptophilic $U(1)$ Models: Modification in $U(1)_{L_{\mu}-L_{\tau}}$

Understand

In this work, we investigate the beyond standard model (BSM) impact of leptophilic U(1) models, namely $ U(1)_{L_\mu-L_e}$, $U(1)_{L_e-L_\tau}$ and $U(1)_{L_\mu-L_\tau}$ on coherent elastic neutrino-nucleus scattering (CE$\nu$NS) and hence its effect on dark matter (DM) direct detection experiments.

• Imposing the latest relevant experimental constraints on these models, we obtain $\mathcal{O}(50\%)$ enhancement for case of $U(1)_{L_\mu-L_\tau}$ in a region $m_Z' \approx 20~$MeV.
• Subsequently, we observe that the enhancement seen in CE$\nu$NS is roughly getting translated to enhancement by a factor of 2.7 (for Germanium based detectors) and 1.8 (for Xenon based detectors) in the neutrino scattering event rate which eventually enhances the neutrino floor by same amount.
• This enhancement is more prominent in the region with DM masses less than 10 GeV.