[m(χc1) = 3510.71±0.04±0.09 MeV; m(χc2) = 3556.10±0.06±0.11 MeV] [m(χc2) – m(χc1) = 45.39±0.07±0.03 MeV] [Γ(χc2) = 2.10±0.20±0.02 MeV] Today, at the open session of the Large Hadron Collider Committee, LHCC, the LHCb collaboration presented the result of a precise mass measurements of χc1 and χc2 mesons, performed for the first time by utilising the newly…