Charmed baryon spectroscopy and light flavor symmetry from lattice QCD
Charmed baryon spectroscopy and light flavor symmetry from lattice QCD
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DOI：
10.1103/physrevd.92.034504
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发表时间：
2015-03
影响因子：
5
通讯作者：
G. Bali;S. Collins;P. P'erez-Rubio
中科院分区：
文献类型：
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作者：
G. Bali;S. Collins;P. P'erez-Rubio
我们确定了具有正宇称和负宇称的单魅力自旋和双魅力自旋1/2和3/2重子的基态和第一激发态质量。采用 Nf=2+1 非微扰改进的威尔逊三叶草费米子的配置，相同的夸克作用也用于价夸克，包括粲夸克。计算出π介子质量范围为 Mπ∼259–460 MeV、晶格间距为 a∼0.075 fm 的光谱。通过比较具有两种不同线性空间范围（1.8 fm 和 2.4 fm）的晶格来研究有限体积效应。从 SU(3) 极限逼近物理点，保持风味平均轻夸克质量固定。重子质量是利用奇光夸克质量差的展开式来推断的。大多数粒子落入具有良好约束外推的预期 SU(3) 多重态，例外情况具有可能更复杂的内部结构。通过对单魅力重子的质量和分裂的实验发现了总体一致。作为计算的一部分，对较低位置的粲离子、D 和 Ds 光谱进行了分析，以评估离散化误差。再现了总光谱，包括 Ds0*、Ds1 和 D1 介子，而在此单晶格间距下，超精细分裂的结果太低了 10-20 MeV。
We determine the ground state and first excited state masses of singly and doubly charmed spin 1/2 and 3/2 baryons with positive and negative parity. Configurations with Nf=2+1 nonperturbatively improved Wilson-clover fermions were employed, with the same quark action also being used for the valence quarks, including the charm. The spectrum is calculated for pion masses in the range Mπ∼259–460 MeV at a lattice spacing a∼0.075 fm. Finite volume effects are studied comparing lattices with two different linear spatial extents (1.8 fm and 2.4 fm). The physical point is approached from the SU(3) limit keeping the flavor averaged light quark mass fixed. The baryon masses are extrapolated using expansions in the strange-light quark mass difference. Most particles fall into the expected SU(3) multiplets with well-constrained extrapolations, the exceptions having a possibly more complex internal structure. Overall agreement is found with experiment for the masses and splittings of the singly charmed baryons. As part of the calculation an analysis of the lower lying charmonium, D and Ds spectra was performed in order to assess discretization errors. The gross spectra are reproduced, including the Ds0*, Ds1 and D1 mesons, while at this single lattice spacing hyperfine splittings come out 10–20 MeV too low.