Precise measurements of the properties of the B 1 (5721) 0 , + and B 2 * (5747) 0,+ states and observation of B + , 0 π − , + mass structures

Invariant mass distributions of B + π − and B 0 π + combinations are investigated in order to study excited B mesons. The analysis is based on a data sample corresponding to 3.0 fb −1 of pp collision data, recorded by the LHCb detector at centre-of-mass energies of 7 and 8 TeV. Precise measurements of the masses and widths of the B 1 (5721) 0,+ and B 2 (5747) 0,+ states are reported. Clear enhancements, particularly prominent at high pion transverse momentum, are seen over background in the mass range 5850-6000 MeV in both B + π − and B 0 π + combinations. The structures are consistent with the presence of four excited B mesons, labelled B J (5840) 0,+ and B J (5960) 0,+ , whose masses and widths are obtained under different hypotheses for their quantum numbers.