We investigate Majorana dark matter in a new variant of $U(1{)}_{L_{\mu }-L_{\tau }}$ gauge extension of the Standard Model, where the scalar sector is enriched with an inert doublet and a ($\overline{3}$, 1, $1/3$) scalar leptoquark. We compute the weakly interacting massive particle–nucleon cross section in the leptoquark portal and the relic density mediated by inert doublet components, the leptoquark, and the new $Z^{\prime }$ boson. We constrain the parameter space consistent with the Planck limit on the relic density and the PICO-60 and LUX bounds on the spin-dependent direct detection cross section. Furthermore, we constrain the new couplings from the present experimental data on $\mathrm{Br}(\tau \to \mu {\nu }_{\tau }{\overline{\nu }}_{\mu })$, $\mathrm{Br}(B\to X_s\gamma )$, $\mathrm{Br}({\overline{B}}^0\to {\overline{K}}^0{\mu }^{+}{\mu }^{-})$, $\mathrm{Br}(B^{+}\to K^{+}{\tau }^{+}{\tau }^{-})$, and $B_s-\overline{B_s}$ mixing, which occur at the one-loop level in the presence of the $Z^{\prime }$ and leptoquark. Using the allowed parameter space, we estimate the form-factor-independent $P_{4,5}^{\prime }$ observables and the lepton nonuniversality parameters $R_K$, $R_{K^{*}}$, and $R_{\varphi }$. We also briefly discuss neutrino mass generation at the one-loop level and the viable parameter region to explain current neutrino oscillation data.

• Received 10 September 2018
• Revised 21 January 2019

DOI:https://doi.org/10.1103/PhysRevD.99.035042

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP³.

Published by the American Physical Society