Green Jeremy R, Hanlon Andrew D, Junnarkar Parikshit M, Wittig Hartmut
Theoretical Physics Department, CERN, 1211 Geneva 23, Switzerland.
Helmholtz-Institut Mainz, Johannes Gutenberg-Universität, 55099 Mainz, Germany; GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany; and Physics Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
Phys Rev Lett. 2021 Dec 10;127(24):242003. doi: 10.1103/PhysRevLett.127.242003.
We present the first study of baryon-baryon interactions in the continuum limit of lattice QCD, finding unexpectedly large lattice artifacts. Specifically, we determine the binding energy of the H dibaryon at a single quark-mass point. The calculation is performed at six values of the lattice spacing a, using O(a)-improved Wilson fermions at the SU(3)-symmetric point with m_{π}=m_{K}≈420 MeV. Energy levels are extracted by applying a variational method to correlation matrices of bilocal two-baryon interpolating operators computed using the distillation technique. Our analysis employs Lüscher's finite-volume quantization condition to determine the scattering phase shifts from the spectrum and vice versa, both above and below the two-baryon threshold. We perform global fits to the lattice spectra using parametrizations of the phase shift, supplemented by terms describing discretization effects, then extrapolate the lattice spacing to zero. The phase shift and the binding energy determined from it are found to be strongly affected by lattice artifacts. Our estimate of the binding energy in the continuum limit of three-flavor QCD is B_{H}^{SU(3){f}}=4.56±1.13{stat}±0.63_{syst} MeV.
我们展示了在格点量子色动力学连续极限下对重子-重子相互作用的首次研究，发现了出乎意料的大格点赝品。具体而言，我们在单个夸克质量点确定了H双重子的结合能。计算在六个格点间距a的值下进行，在具有mπ = mK ≈ 420 MeV的SU(3)对称点使用O(a)改进的威尔逊费米子。通过对使用蒸馏技术计算的双局域双重子插值算符的关联矩阵应用变分方法来提取能级。我们的分析采用吕舍尔的有限体积量子化条件，从能谱确定散射相移，反之亦然，在双重子阈值之上和之下均如此。我们使用相移的参数化对格点能谱进行全局拟合，并辅以描述离散化效应的项，然后将格点间距外推到零。发现相移及其确定的结合能受到格点赝品的强烈影响。我们在三味量子色动力学连续极限下对结合能的估计是BH^SU(3)_f = 4.56 ± 1.13_stat ± 约0.63_syst MeV。
