Precise measurements of the properties of the B_1(5721)^(0,+) and B_2*(5747)^(0,+) states and observation of B^(+,0) pi^(-,+) mass structures

TL;DR

This paper reports precise measurements of excited B meson states and observes new mass structures in B pi combinations, enhancing understanding of heavy meson spectroscopy.

Contribution

It provides the first precise measurements of B_1(5721) and B_2*(5747) states and reports observation of new B meson mass structures in high-energy proton-proton collisions.

Findings

Measured masses and widths of B_1(5721) and B_2*(5747) states.

Observed mass structures around 5850-6000 MeV in B pi combinations.

Identified potential new excited B meson states B_J(5840) and B_J(5960).

Abstract

Invariant mass distributions of B+pi- and B0pi+ 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+pi- and B0pi+ 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.