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arXiv 2510.24596hep-lathep-phnucl-th
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来自格点QCD的低重子共振态

Low-lying baryon resonances from lattice QCD

Colin Morningstar

AI总结:

本研究利用格点量子色动力学的非微扰蒙特卡罗方法,结合散射K矩阵参数化拟合有限体积能谱,得到Δ共振态结果,发现Λ(1405)附近的双极点结构,并探讨了该方法应用于Roper共振态的前景。

摘要:

从量子色动力学计算重子共振态的性质,需要通过对场构型进行积分来评估强子算符之间的时间关联,这些场构型由与作用量相关的相位加权。通过将量子色动力学构建在虚时的时空格点上,这类积分可采用带重要性抽样的马尔可夫链蒙特卡罗方法非微扰地完成。格点有限体积内定态的能量可从时间关联中提取。包含散射$K$-矩阵和复杂“盒矩阵”的量子化条件也能给出有限体积能谱。通过对散射$K$-矩阵进行适当参数化,$K$-矩阵参数的最优拟合值是那些能产生与蒙特卡罗计算所得能谱最匹配的有限体积能谱的参数。本文给出了$Δ$共振态的结果,并概述了$Λ(1405)$共振态附近能量的散射研究,显示出双极点结构。文中还讨论了将该方法应用于罗珀(Roper)共振态的前景。

英文摘要:

Calculating the properties of baryon resonances from quantum chromodynamics requires evaluating the temporal correlations between hadronic operators using integrations over field configurations weighted by a phase associated with the action. By formulating quantum chromodynamics on a space-time lattice in imaginary time, such integrations can be carried out non-perturbatively using a Markov-chain Monte Carlo method with importance sampling. The energies of stationary states in the finite volume of the lattice can be extracted from the temporal correlations. A quantization condition involving the scattering $K$-matrix and a complicated ``box matrix'' also yields a finite-volume energy spectrum. By appropriately parametrizing the scattering $K$-matrix, the best-fit values of the $K$-matrix parameters are those that produce a finite-volume spectrum which most closely matches that obtained from the Monte Carlo computations. Results for the $Δ$ resonance are presented, and a study of scattering for energies near the $Λ(1405)$ resonance is outlined, showing a two pole structure. The prospects for applying this methodology to the Roper resonance are discussed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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