2019/10/31 by Yu Meng, Chuan Liu, Ke-Long Zhang · 1 citation
Physics and Astronomy · #hep-lat #hep-ex #hep-ph
paper · pdf · doi:10.1103/physrevd.102.054506
published as Phys. Rev. D 102, 054506 (2020) · 6 pages 5 figures. Updated version compared with older version that has been withdrawn. Two ensembles are studied so that the size of finite lattice spacing errors can be estimated
arxiv created 2020/03/14 · arxiv updated 2020/09/23
Three photon decay rate of J/ψ is studied using two Nf=2 twisted mass gauge ensembles with lattice spacings a≃ 0.085 fm (I) and 0.067 fm(II). Using a new method, only the correlation functions directly related to the physical decay width are computed with all polarizations of the initial and final states summed over. Our results for such rare decay on the two ensembles are: BI,II(J/ψ→ 3γ)=(1.614 ± 0.016 ± 0.261)× 10-5,(1.809 ± 0.051 ± 0.295)× 10-5 where the first errors are statistical and the second are estimates from systematics. We also propose a method to analyze the Dalitz plot of the corresponding process based on the lattice data which can provide direct information for the experiments.