$$\varvec{B^0\rightarrow K^{*0}\mu ^+\mu ^-}$$ B 0 → K ∗ 0 μ + μ - decay in the aligned two-Higgs-doublet model

Abstract

In the aligned two-Higgs-doublet model, we perform a complete one-loop computation of the short-distance Wilson coefficients $$C_{7,9,10}^{(\prime )}$$ , which are the most relevant ones for $$b\rightarrow s\ell ^+\ell ^-$$ transitions. It is found that, when the model parameter $$\left| \varsigma _{u}\right| $$ is much smaller than $$\left| \varsigma _{d}\right| $$ , the charged scalar contributes mainly to chirality-flipped $$C_{9,10}^\prime $$ , with the corresponding effects being proportional to $$\left| \varsigma _{d}\right| ^2$$ . Numerically, the charged-scalar effects fit into two categories: (A) $$C_{7,9,10}^\mathrm {H^\pm }$$ are sizable, but $$C_{9,10}^{\prime \mathrm {H^\pm }}\simeq 0$$ , corresponding to the (large $$\left| \varsigma _{u}\right| $$ , small $$\left| \varsigma _{d}\right| $$ ) region; (B) $$C_7^\mathrm {H^\pm }$$ and $$C_{9,10}^{\prime \mathrm {H^\pm }}$$ are sizable, but $$C_{9,10}^\mathrm {H^\pm }\simeq 0$$ , corresponding to the (small $$\left| \varsigma _{u}\right| $$ , large $$\left| \varsigma _{d}\right| $$ ) region. Taking into account phenomenological constraints from the inclusive radiative decay $$B\rightarrow X_{s}{\gamma }$$ , as well as the latest model-independent global analysis of $$b\rightarrow s\ell ^+\ell ^-$$ data, we obtain the much restricted parameter space of the model. We then study the impact of the allowed model parameters on the angular observables $$P_2$$ and $$P_5'$$ of $$B^0\rightarrow K^{*0}\mu ^+\mu ^-$$ decay, and we find that $$P_5'$$ could be increased significantly to be consistent with the experimental data in case B.