E1 Transitions from the Υ'' State and the Fine Structure of the χ'b States
Abstract
Using the CUSB-II detector at the Cornell Electron Storage Ring, we have made precision measurements of the electric dipole transition rates from Υ'' toχ'b, which are in excellent agreement with theory. The fine-structure splitting is found to beM(χ'b2)-M(χ'b1=13.5+/-0.4+/-0.5 MeV and(χ'b1)-M(χ'b0)=23.2+/-0.7+/-0.7 MeV, leading to a ratioR=0.584+/-0.024+/-0.02. The fine structure measures the relative contributions of the spin-orbit interaction a=9.5+/-0.2+/-0.1 MeV and tensor interaction b=2.3+/-0.1+/-0.1 MeV. We also find that the long-range confining potential transforms as a Lorentz scalar.
- Publication:
-
Physical Review Letters
- Pub Date:
- June 1991
- DOI:
- 10.1103/PhysRevLett.66.3113
- Bibcode:
- 1991PhRvL..66.3113N
- Keywords:
-
- 14.40.Gx;
- 12.40.Qq;
- 13.40.Hq;
- Mesons with S=C=B=0 mass>2.5 GeV;
- Electromagnetic decays