Observation of the Radiative Decays of ψ (1S) to χc1
Journal
Physical Review Letters
Journal Volume
124
Journal Issue
12
Date Issued
2020
Author(s)
P. Katrenko et al. (Belle Collaboration)
Abstract
We report the first observation of the radiative decay of the ψ(1S) into a charmonium state. The significance of the observed signal of ψ(1S)→γχc1 is 6.3 standard deviations including systematics. The branching fraction is calculated to be B[ψ(1S)→γχc1]=[4.7-1.8+2.4(stat)-0.5+0.4(sys)×10-5]. We also searched for ψ(1S) radiative decays into χc0,2 and ηc(1S,2S), and set upper limits on their branching fractions. These results are obtained from a 24.9 fb-1 data sample collected with the Belle detector at the KEKB asymmetric-energy e+e- collider at a center-of-mass energy equal to the ψ(2S) mass using ψ(1S) tagging by the ψ(2S)→ψ(1S)π+π- transitions. ? 2020 authors. Published by the American Physical Society.
Subjects
Atomic physics; Asymmetric energy; Belle detectors; Branching fractions; Data sample; E+e- collider; Radiative decay; Standard deviation; Upper limits; Physics; article; taxonomy
SDGs
Type
journal article