2020/11/08 by Dan-Dan Shen, Shen, Dan-Dan, Chong-Yang Lu +5
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #hep-ex #hep-ph
paper · pdf · doi:10.48550/arxiv.2011.03942
10 pages,3 figures,6 tables
arxiv created 2020/11/08 · arxiv updated 2020/11/10
Motivated by very recent measurement of the radiative decays of Υ(1S) to χc1 at Belle, we use the nonrelativistic QCD factorization theory and calculate the branching fractions of the radiative decays of bottomonium into S-wave and P-wave charmonium, i.e. Υ(nS) → ηc(nS)+γ and Υ(nS)→ χcJ+γ. We systematically studied the branching fractions of the radiative decays of bottomonium into charmonium. Compared to the previous calculation, we obtained the analytical expression for the decay widths and considered the color-octet contributions. For Υ(nS) → ηc(nS)+γ, the relativistic corrections are also obtained. Through the calculation, the theoretical prediction for Υ(1S)→χc1+γ is still smaller than the recent Belle measurement. Further theoretical work and experimental analysis are necessary to understand the χc1 production mechanism in upsilon decays.