Searches for 25 rare and forbidden decays of D+ and $$ {D}_s^{+} $$ mesons

A search is performed for rare and forbidden charm decays of the form $D_{(s)}^+ \to h^\pm \ell^+ \ell^{(\prime)\mp}$, where $h^\pm$ a pion or kaon $\ell^{(')\pm}$ an electron muon. The measurements are using proton-proton collision data, corresponding to integrated luminosity $1.6\text{fb}^{-1}$, collected by LHCb experiment in 2016. No evidence observed 25 decay modes that investigated $90\%$ confidence level limits on branching fractions set between $1.4\times10^{-8}$ $6.4\times10^{-6}$. In most cases, these results represent improvement existing one two orders magnitude.