"Figure 5(a)" of "Search for charged-lepton-flavour violating $\mu\tau qt$ interactions in top-quark production and decay in $pp$ collisions at $\sqrt{s}= 13$ TeV with the ATLAS detector at the LHC"

Expected and observed 95$\%$ CL upper limits on the branching ratio corresponding to the decay of a top quark to a muon and a tau lepton through a cLFV process for scalar, vector and tensor couplings. In the vector case, all vector operators are assumed to contribute simultaneously with the same effective coupling strength. The table shows the endpoint values of $\mathcal{B}(\mathrm{t}\to\mu\tau\mathrm{u})$ and $\mathcal{B}(\mathrm{t}\to\mu\tau\mathrm{c})$, which are interpolated linearly for each limit.