2020/04/30 by Chuan Liu, Yu Meng, Ke-Long Zhang
Mathematics · Physics and Astronomy · #Combinatorics #Gauge theory #High-Energy Particle Collisions Research #Identity (music) #Lattice (music) #Lattice gauge theory #Mathematical physics #Mathematics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #hep-ex #hep-lat #hep-ph
paper · pdf · doi:10.1103/physrevd.102.034502
published as Phys. Rev. D 102, 034502 (2020) · 9 pages, 5 figures
openalex created_date 2020/04/17 · openalex publication_date 2020/08/05 · arxiv created 2020/08/07 · arxiv updated 2020/08/12 · openalex updated_date 2026/08/05
Using a recently proposed method [Y. Meng, C. Liu, and K. L. Zhang, arXiv:1910.11597v3], we study the two-photon decay rate of \ensuremathηc using two Nf=2 twisted mass gauge ensembles with lattice spacings 0.067 fm and 0.085 fm. The results obtained from these two ensembles can be extrapolated in a naive fashion to the continuum limit, yielding a result that is consistent with the experimental one within two standard deviations. To be specific, we obtain the results for two-photon decay of \ensuremathηc as B(\ensuremathηc\ensuremath→2\ensuremathγ)=1.29(3)(18)\ifmmode×\else\texttimes\fi10^\ensuremath-4 where the first error is statistical and the second is our estimate for the systematic error caused by the finite lattice spacing. It turns out that Ward identity for the vector current is of vital importance within this new method. We verify that the Ward identity is violated for local current with a finite lattice spacing, however it will be restored after the continuum limit is taken.