We have studied the inclusive photon spectra in Y(2S) and Y(3S) decays using a large statistics data sample obtained with the CLEO III detector. We present the most precise measurements of electric dipole (E1) photon transition rates and photon energies for Y(2S) → γχbJ(1P) and Y(3S) → γχbJ(2P) (J = 0, 1, 2). We measure the rate for a rare E1 transition Y(3S) → γχb0(1P) for the first time. We also set upper limits on the rates for the hindered magnetic dipole (M1) transitions to the ηb (1S) and ηb (2S) states.
ASJC Scopus subject areas
- Physics and Astronomy(all)