Study of $$ {mathrm{B}}_{mathrm{c}}^{+} o mathrm{J}/psi {mathrm{D}}_{mathrm{s}}^{+} $$ and $$ {mathrm{B}}_{mathrm{c}}^{+} o mathrm{J}/psi {mathrm{D}}_{mathrm{s}}^{ast +} $$ decays in pp collisions at $$ sqrt{mathrm{s}} $$ = 13 TeV with the ATLAS detector Documento