Search for the $ {B}_c^{+} $ → χc1(3872)π+ decay

A search for the decay ${B}_c^{+}$ → χ c1(3872)π + 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 9 fb −1. No significant signal is observed. Using the decay ${B}_c^{+}$ → ψ(2S)π + 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/\psi {\pi}^{+}{\pi}^{-}}}{{\mathcal{B}}_{\psi (2S)\to J/\psi {\pi}^{+}{\pi}^{-}}}