Observation of an excited $B_c^{+}$ state

LHCb collaboration, R. Aaij, C. Abellán Beteta +848

Using $pp$ collision data corresponding to an integrated luminosity of $8.5{\mathrm{fb}}^{-1}$ recorded by the LHCb experiment at centre-of-mass energies of $\sqrt{s}=7$, $8$ and…