Measurement of Resonance Parameters of Orbitally Excited Narrow B0 Mesons

We report a measurement of resonance parameters of the orbitally excited (L =1) narrow B0 mesons in decays to B(*)+ pi+- using 1.7 fb-1 of data collected by the CDF II detector at the Fermilab Tevatron. The mass and width of the B*0_2 state are measured to be m(B*0_2) 5740.2+1.7_-1.8(stat.)+0.9_-0.8(syst.) MeV/c2 and Gamma(B*0_2) 22.7+3.8_-3.2 (stat.)3.2_-10.2(syst.) MeV/c2. The mass difference between the B*0_2 and B0_1 states is measured to be 14.9+2.2_-2.5(stat.)+1/2_-1.4(syst.) MeV/c2, resulting in a B0_1 mass of 5725.3+1.6_-2.2(stat.)+1.4_-1.5(syst.) MeV/c2. This is currently the most precise measurement of the masses of these states and the first measurement of the B*0_2 width.