Dark matter contribution to $b\to s μ^+ μ^-$ anomaly in local $U(1)_{L_μ-L_τ}$ model

Seungwon Baek

Published 2017-07-14Version 1

We propose a local $U(1)_{L_\mu-L_\tau}$ model to explain $b \to s \mu^+ \mu^-$ anomaly observed at the LHCb and Belle experiments. The model also has a natural dark matter candidate. We introduce colored $SU(2)_L$-doublet scalar $\widetilde{q}$ to mediate $b \to s$ transition at one-loop level. The $U(1)_{L_\mu-L_\tau}$ is spontaneously broken by the scalar $S$. All the new particles are charged under $U(1)_{L_\mu-L_\tau}$. We can obtain $C_9^{\mu,{\rm NP}} \sim -1$ to explain the $b \to s\mu^+\mu^-$ anomaly and explain the correct dark matter relic density of the universe, $\Omega_{\rm DM} h^2 \approx 0.12$ while evading constraints from other FCNC processes such as $b \to s \gamma$ or $B_s-\overline{B}_s$ mixing. Our model can be tested by searching for new colored scalar at the LHC and $B \to K^* \nu \overline{\nu}$ process at Belle-II.