Observation of I (2S) →γηb (1S) Decay
Journal
Physical Review Letters
Journal Volume
121
Journal Issue
23
Date Issued
2018
Author(s)
B. G. Fulsom et al. (Belle Collaboration)
Abstract
We report the observation of I(2S)→γηb(1S) decay based on an analysis of the inclusive photon spectrum of 24.7 fb-1 of e+e- collisions at the I(2S) center-of-mass energy collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. We measure a branching fraction of B[I(2S)→γηb(1S)]=(6.1-0.7-0.6+0.6+0.9)×10-4 and derive an ηb(1S) mass of 9394.8-3.1-2.7+2.7+4.5 MeV/c2, where the uncertainties are statistical and systematic, respectively. The significance of our measurement is greater than 7 standard deviations, constituting the first observation of this decay mode. ? 2018 authors. Published by the American Physical Society.
Subjects
Atomic physics; Asymmetric energy; Belle detectors; Branching fractions; Center-of-mass energies; Decay mode; E+e- collider; Photon spectra; Standard deviation; Physics
SDGs
Type
journal article