Measurement of B-hadron masses at CDF run II

Abstract

We measure the mass of b-hadrons in exclusive J/[psi]-decay modes. The correct momentum scale is established by the following steps: validate and quantify distortions or systematic effects in the Central Outer Tracker and Silicon Vertex Detector, apply and fine tune the energy loss corrections per track, and finally tune the magnetic field scale. With the momentum scale established, we find: m(B⁺) = 5279.10 ± 0.41 (stat) ± 0.36 (sys), m(B⁰) = 5279.63 ± 0.53 (stat) ± 0.33 (sys), m(B[s]⁰) = 5366.01 ± 0.73 (stat) ± 0.33 (sys), m(A[b]) = 5619.7 ± 1.2 (stat) ± 1.2 (sys) MeV/c². The measurements of the A[b] and B[s], masses are the current world best. The value of the A[b] mass is consistent with the CDF run I measurement resolving a discrepancy in the PDG average.