共查询到20条相似文献,搜索用时 71 毫秒
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最近,文献[1]将辅助场方法应用于准相对论性夸克模型中,获得了一个解析的非奇异轻介子质量公式。本文将这种方法推广到奇异轻介子的情况,得到了一个味道依赖的轻介子质量公式。结果表明,质量公式预言的低激发态质量谱与实验值吻合良好,平均误差在30 MeV左右。质量公式预言的高激发态质量谱和其他文献(特别是弦模型)的计算相比,也符合较好。Recently, with the help of auxiliary field method, Ref.[1] obtains an analytical mass formula for nonstrange light mesons in quasi-relativistic quark model. In this work, we generalize this method to the case of strange light mesons, and obtain a mesonic mass formula which is flavor-dependent. The results show that the mass of low excitations given by the mass formula are in good agreement with the experimental data and the average error is around 30 MeV. Our mass predictions for the high states also agree well with the other calculations in the literatures, particularly, the string model calculations. 相似文献
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本工作重新考察了相对论弦模型和准相对论夸克模型中轻介子的类雷吉谱。基于辅助场技术,提出了非奇异轻介子的一个解析质量公式,由此推导出了一个准线性的Regge-Chew-Frautschi轨迹关系,并将此关系用相应介子的实验数据(PDG)进行了检验。检验结果表明,和实验观测数据比较,夸克模型对介子质量的预言与弦模型的相符,但在角动量较大时,夸克模型的预言稍微优于弦模型。We revisit the Regge-like spectra of light mesons in the relativistic string model and the simirelativistic quark model. An analytical mass formula is proposed for light mesons based on the auxiliary field technique, and a quasi-linear Regge-Chew-Frautschi plot with flavor dependence is derived and verified with the experimental data(PDG) for light mesons.The results show that the quark model predictions for meson masses agree with those of the string model, but are slightly better when the angular momentum is relatively large as compared with the observed data. 相似文献
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核子中奇异-反奇异夸克分布的不对称性是核子结构研究中的重要非微扰效应,
然而至今未被实验所直接检验.为了探讨测量这种奇异分布不对称性的有效方法,考察了轻味夸克碎裂效应对测量奇异分布不对称性的影响.建议通过直接测量高能中微子和反中微子的带电流深度非弹散射中的带电和中性D介子的微分截面来测量奇异分布的不对称性.这种方法能够使奇异分布不对称性与轻味夸克碎裂的效应相分离. 相似文献
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从单胶子交换正反夸克对产生模型出发,计算了N-N相互作用中方盒图的等效两介子交换势,它随r的变化关系与唯象σ介子交换势随r的变化关系的趋势是一致的. 相似文献
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对于以赝标介子场为背景场的夸克模型,我们使用Seeley-DeWitt系数算出了味无关轴矢流,这个流与质子中的夸克自旋成分直接相关.在大Nc展开下,这个流是O(1). 相似文献
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研究了e^ e^-湮没中“初始”轻夸克和胶子劈裂产生的e^-组合为D^-介子(包括D^-,Ds^-,D^-0)或D^-*介子(包括D*^-,Ds^*-,D^-*0)的过程.发现尤其在√s=Mz处,其产额相对较大,当限制D^-或D^-*的能量大于20GeV时,它和c夸克碎裂产物的不变质量谱在稍大于2MD^-附近有一个峰,这是该过程区别于其它D^-或^-*介子产生过程的显著特征.此过程产生的矢量介子基本上是纵向极化的,与实验上观测到的D^-*介子的纵向极化一致. 相似文献
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本文用共有夸克模型讨论了核内弱相互作用过程中的夸克效应,计算出了不同超核中Λ粒子非介子衰变的宽度,并与其它模型的计算结果及实验值进行了比较. 相似文献
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利用夸克模型,考虑π介子云对质子,特别是中子的形状因子的影响,计算了质子和中子的电磁形状因子.对中子的性质给予了较好的描述. 相似文献
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Based on a relativistic quark model approach, the transition properties of the first nucleon resonance △(1232), and the coupling constants gπNN, g△πN are investigated. Tvo different vays to remove the center of mass motion are considered. The results of the relativistic approaches with and without center ofmass correction are compared with those of nonrelativistic constituent quark model. Moreover, pion meson cloud effect on these calculated observables is explicitly addressed. Better results are obtained by taking the pion meson cloud into account. 相似文献
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ZHENG Yu-Ming FUCHS C. SRISAWAS Pornrad FAESSLER Amand YAN Yu-Peng KOBDAJ Chinorat XING Yong-Zhong 《理论物理通讯》2008,50(9):725-728
The sigma meson production in p + ^12C and p A- ^40Ca reactions at the incident energy Ep = 1.5 GeV is investigated within the Quantum Molecular Dynamics model. The simulation results indicate a distinctive A dependence of the sigma production, that is, the increase of A is followed by an increase of the production cross sections. We find that the σ meson production in proton-induced reactions is strongly medium-dependent, and the produced σ mesons decaying in a denser medium experience a stronger mass shift towards lower masses. This mass shift is an experimentally accessible observable in the final state pion pairs, which do not suffer from reabsorption by the surrounding nucleons. It is pointed out that the ratio of measured sigma cross sections as a function of the sigma invariant-mass from various reactions is a good probe to explore the existence of the σ meson in a dense nuclear environment. 相似文献
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A power law potential which is an equal admixture of scalar and vector parts with effective powerv ∞ 1/m
q
, is proposed as a quark confining potential in the Dirac equation. The model is capable of predicting the meson spectroscopy
encompassing both light and heavy quark-antiquark systems in a unified way. 相似文献
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We calculate the meson mass spectra in a quark potential model by using the complete Fermi-Breit potential including the terms of orbit-orbit interaction, spin-orbit coupling, and tensor force interaction. We find that these terms give nontrivial contributions to the calculated meson spectra. The orbit-orbit coupling term may lead to an instability of the solution of the Schrodinger equation and should be regularized. 相似文献
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We calculate the meson mass spectra in a quark potential model by using the complete Fermi-Breit potential including the terms of orbit-orbit interaction, spin-orbit coupling, and tensor force interaction. We find that these terms give nontrivial contributions to the calculated meson spectra. The orbit-orbit coupling term may lead to an instability of the solution of the Schr5dinger equation and should be regularized. 相似文献
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In a previous work, we proposed an extended Nmnbu-Jona-Lasinio (NJL) model including heavy quark flavors. In this work, we will calculate strong and radiative decays of vector mesons in this extended NJL model, including light p, w, K*, θ and heavy D*, D*s, B*, Bs*. 相似文献