Extended-soft-core Baryon-Baryon Model II. Hyperon-Nucleon Interaction
Extended-soft-core Baryon-Baryon Model II. Hyperon-Nucleon Interaction
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DOI：
10.1103/physrevc.73.044008
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发表时间：
2006-03
影响因子：
3.1
通讯作者：
T. Rijken;Y. Yamamoto
中科院分区：
文献类型：
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作者：
T. Rijken;Y. Yamamoto
YN结果来自扩展的软核(ESC)相互作用。它们由局域势和非局域势组成，这是因为(I)单玻色子交换(OBE)，它是赝标、矢量、标量和轴向介子的NONET的成员；(Ii)衍射交换；(Iii)双赝标交换；(Iv)介子对交换(MPE)。OBE和对顶点都受高斯形状因子的调节，产生在原点附近具有软行为的势。重子-重子-介子(BBM)顶点截断质量的分配取决于OBE交换介子的SU(3)分类和MPE的类似方案。ESC模型的特定版本，称为ESC04[T.A.Rijken，Phys.C73,044007(2006年)]，使用破缺的SU(3)对称性以统一的方式描述了核子-核子(NN)和超子-核子(YN)相互作用。新的成分包括(I)轴向量介子势和(Ii)标量和轴向矢量介子形状因子中的零。这些创新首次使该模型的参数接近于{sup3}p{sub0}夸克-反夸克产生模型的预测成为可能。F/(F+D)比率也是如此。此外，零的引入有助于避免更多不想要的束缚态的发生。破缺的SU(3)对称性用于连接NN和Yn通道，这使得在NN拟合后只剩下几个自由参数用于确定Yn相互作用。特别地，使用神经网络分析的耦合常数作为输入，通过SU(3)计算了介子-重子耦合常数。作为一种新的特征，对于BBM耦合，采用了具有Gell-Mann-Okubo超电荷破缺的{sup3}P{sub0}模型，允许耦合常数的中强味道对称性破缺。对有无FSB的ESC模型均有很好的拟合效果。在OBE、TME和MPE势中包含了{lambda}p和{lambda}n通道中的电荷对称性破坏，这是一种SU(2)同位旋破坏。描述了对NN和YN散射数据的同时拟合，使用了ESC模型的不同选项。对于所选择的能量为0T{SUB LAB}{SUP=}350 MeV的4233 NN数据，通常达到{chi}{SUP2}/N{SUB DATA}=1.22。对于从最近的KEK实验中得到的通常的35Yn数据和3{sigma}{sup+}p个截面，获得了E289{chi}{sup 2}/yn{subdata}{Approx_Equity}0.63。特别是，对于静态的非弹性俘获比，我们能够很好地拟合精确的实验数据r{subR}=0.468{+-0.010。本文介绍的ESC04的四个版本(a、b、c和d)对超核给出了不同的结果。所报道的G矩阵计算是对核物质中的YN({lambda}N，{sigma}N，{xi}N)对进行的。测得的井深(U{SUB{lambda}}、U{SUB{sigma}}、U{SUB{Xi}})显示了ESC04a-d的明显特征。{lambda}{lambda}相互作用与{sub{lambda}}{sub{lambda}}{sup 6}He的观测数据是一致的。通过唯象地考虑矢量介子质量的变化，研究了可能的三体效应。
The YN results are presented from the extended soft-core (ESC) interactions. They consist of local and nonlocal potentials because of (i) one-boson exchanges (OBE), which are the members of nonets of pseudoscalar, vector, scalar, and axial mesons; (ii) diffractive exchanges; (iii) two-pseudoscalar exchange; and (iv) meson-pair exchange (MPE). Both the OBE and pair vertices are regulated by Gaussian form factors producing potentials with a soft behavior near the origin. The assignment of the cutoff masses for the baryon-baryon-meson (BBM) vertices is dependent on the SU(3) classification of the exchanged mesons for OBE and a similar scheme for MPE. The particular version of the ESC model, called ESC04 [T. A. Rijken, Phys. Rev. C 73, 044007 (2006)], describes nucleon-nucleon (NN) and hyperon-nucleon (YN) interactions in a unified way using broken SU(3) symmetry. Novel ingredients are the inclusion of (i) the axial-vector meson potentials and (ii) a zero in the scalar- and axial-vector meson form factors. These innovations made it possible for the first time to keep the parameters of the model close to the predictions of the {sup 3}P{sub 0} quark-antiquark creation model. This is also the case for the F/(F+D) ratios. Furthermore, the introduction of the zero helped to avoidmore » the occurrence of unwanted bound states. Broken SU(3) symmetry serves to connect the NN and the YN channels, which leaves after fitting NN only a few free parameters for the determination of the YN interactions. In particular, the meson-baryon coupling constants are calculated via SU(3) using the coupling constants of the NN analysis as input. Here, as a novel feature, medium-strong flavor-symmetry breaking (FSB) of the coupling constants was allowed, using the {sup 3}P{sub 0} model with a Gell-Mann-Okubo hypercharge breaking for the BBM coupling. Very good fits for ESC model with and without FSB were obtained. The charge-symmetry breaking in the {lambda}p and {lambda}n channels, which is an SU(2) isospin breaking, is included in the OBE, TME, and MPE potentials. Simultaneous fits to the NN- and the YN-scattering data are described, using different options for the ESC model. For the selected 4233 NN data with energies 0{<=}T{sub lab}{<=}350 MeV, a {chi}{sup 2}/N{sub data}=1.22 was typically reached. For the usual set of 35 YN data and 3 {sigma}{sup +}p cross sections from a recent KEK experiment E289 {chi}{sup 2}/YN{sub data}{approx_equal}0.63 was obtained. In particular, we were able to fit the precise experimental datum r{sub R}=0.468{+-}0.010 for the inelastic capture ratio at rest rather well. The four versions (a,b,c, and d) of ESC04 presented in this article, give different results for hypernuclei. The reported G-matrix calculations are performed for YN ({lambda}N,{sigma}N,{xi}N) pairs in nuclear matter. The obtained well depths (U{sub {lambda}},U{sub {sigma}},U{sub {xi}}) reveal distinct features of ESC04a-d. The {lambda}{lambda} interactions are demonstrated to be consistent with the observed data of {sub {lambda}}{sub {lambda}}{sup 6}He. The possible three-body effects are investigated by considering phenomenologically the changes of the vector-meson masses.« less