基于统一夸克模型的激发重子谱
The excited baryon spectrum from a unified quark model
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中文总结 AI 辅助
本文构建含自旋-轨道与张量相互作用的非相对论组分夸克势模型，拟合最新实验数据后复现多味区介子与重子谱，预言重重子谱并发现模型无法解决激发轻重子谱偏差，明确其有效范围。
中文摘要 AI 辅助
研究多夸克态的常用方法是在夸克势模型框架下求解少体薛定谔方程，多夸克态可包含多种味的夸克，且具有比普通强子更丰富的色结构。此类研究的可靠性要求 underlying 夸克势模型能在单一参数组下同时描述所有味区的介子和重子谱，包括轨道激发和径向激发，但目前尚无夸克势模型完全满足该要求。我们构建了一个包含自旋-轨道相互作用和张量相互作用的简单非相对论组分夸克势模型，并将模型参数重新拟合到最新实验数据，拟合过程中排除了激发轻强子和几个奇特强子候选态。所得参数组可复现所有拟合味区的谱，绝大多数偏差低于20 MeV，最大偏差仍为数十 MeV，这是非相对论组分夸克势模型的典型精度。利用相同参数，我们预言了轨道和径向激发的重重子的谱及内部结构，这些结果有待进一步实验确定；同时用相同参数计算了激发轻重子的谱，计算得到的激发轻重子谱与实验值存在显著偏差，说明我们重新拟合的模型并未解决这些长期存在的偏差问题。该结果界定了非相对论组分夸克势模型的有效范围，该模型通过在统一框架下处理所有味区的介子和重子（包括轨道和径向激发），为多夸克态的少体计算提供了可控的起点，我们也呼吁实验上对预言的态进行搜索。
英文摘要
A common approach to studying the multiquark states is to solve the few-body Schrödinger equation within a quark potential model. The multiquark states may contain quarks with several different flavors and have richer color structures than ordinary hadrons. The reliability of such an investigation requires that the underlying quark potential model can simultaneously describe the meson and baryon spectra across all flavor sectors, including orbital and radial excitations, with a single parameter set. At present, no quark potential model fully satisfies this requirement. We construct a simple nonrelativistic constituent quark potential model that includes spin--orbit and tensor interactions. We refit the model parameters to the latest experimental data. The excited light hadrons and several exotic hadron candidates are excluded from the fit. The resulting parameter set reproduces the spectra across all fitted sectors. The vast majority of deviations are below 20 MeV, while the largest deviations remain of the order of several tens of MeV, which is the typical accuracy of nonrelativistic quark potential models. Using the same parameters, we predict the spectra and internal structures of the orbitally and radially excited heavy baryons, which await further experimental determination. The excited light baryons are calculated with the same parameters. The calculated excited light baryon spectra deviate substantially from experimental values. Our refitted model does not resolve these longstanding discrepancies. The results delimit the range of validity of the nonrelativistic constituent quark potential model. By treating mesons and baryons across all flavor sectors, including both orbital and radial excitations within a unified framework, the model provides a controlled starting point for few-body calculations of multiquark states. We also urge experimental searches for the predicted states.
