Abstract
Using the Columbia University–Stony Brook (CUSB-II) detector we have studied the inclusive photon spectrum from 2.9× Υ(5S) decays. We observe a strong signal due to →Bγ decays. From this we obtain (i) the average -B mass difference, 46.7±0.4 MeV, (ii) the photon yield per Υ(5S) decay, 〈γ/Υ(5S)〉=1.09±0.06, and (iii) the average velocity of the ’s, 〈β〉=0.156±0.010, for a mix of nonstrange (B) and strange () mesons from Υ(5S) decays. From the shape of the photon line, we find that both B and mesons are produced with nearly equal values for the hyperfine splitting of the B and meson systems.
- Received 8 August 1990
DOI:https://doi.org/10.1103/PhysRevLett.65.2947
©1990 American Physical Society