Minimal Z′ explanations of the B → K*μ+μ- anomaly

Recently LHCb has announced a discrepancy of 3.7 sigma in one of the theoretically clean observables accessible through studies of angular correlations in B -> K*mu(+)mu(-). We point out that in the most minimal Z' setup that can address this anomaly there is a model-independent triple correlation between new physics (NP) in B -> K*mu(+)mu(-), B-s - (B) over bar (s) mixing, and nonunitarity of the quark-mixing matrix. This triple correlation can be cast into a simple analytic formula that relates the NP contribution Delta C-9 to the Wilson coefficient of the semileptonic vector operator to a shift in the mass difference Delta M-Bs and a violation of vertical bar V-ud vertical bar(2) + vertical bar V-us vertical bar(2) + vertical bar V-ub vertical bar(2) = 1. In contrast to the individual observables the found relation depends only logarithmically on the Z' mass. We show that our findings allow for useful future tests of the pattern of NP suggested by the B -> K*mu(+)mu(-) anomaly.