Search for the $B_c^{+}\to {\chi }_{c1}(3872){\pi }^{+}$ decay

A search for the decay $B_c^{+}\to {\chi }_{c1}(3872){\pi }^{+}$ is reported using proton-proton collision data collected with the LHCb detector between 2011 and 2018 at centre-of-mass energies of 7, 8, and 13 $TeV$, corresponding to an integrated luminosity of $9f{b}^{-1}$. No significant signal is observed. Using the decay $B_c^{+}\to \psi (2S){\pi }^{+}$ as a normalisation channel, an upper limit for the ratio of branching fractions $${\mathcal{R}}_{\psi (2S)}^{{\chi }_{c1}(3872)}=\frac{{\mathcal{B}}_{B_c^{+}\to {\chi }_{c1}(3872){\pi }^{+}}}{{\mathcal{B}}_{B_c^{+}\to \psi (2S){\pi }^{+}}}\times \frac{{\mathcal{B}}_{{\chi }_{c1}(3872)\to J\mathrm{/}\psi {\pi }^{+}{\pi }^{-}}}{{\mathcal{B}}_{\psi (2S)\to J\mathrm{/}\psi {\pi }^{+}{\pi }^{-}}}<0.05(0.06),$$ is set at the 90,(95)% confidence level.