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arXiv 1408.0763hep-phhep-th
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旋转弦模型与重子谱

A rotating string model versus baryon spectra

Jacob Sonnenschein, Dorin Weissman

摘要:

我们继续把强子描述成具有大质量端点的旋转弦。在本文中,我们提出了重子模型,并面对他们的重子雷奇轨迹。我们表明,这些是最好的拟合模型的一个单一的字符串与夸克在一端和双夸克在其他。这个模型比两端都有一个夸克的Y形弦模型更好。我们展示了这个模型是如何从一个全息重子的弦模型(其中包括一个重子顶点与N_c弦连接)发展到味探测膜的。通过对重子数据的拟合,我们发现没有明确的证据表明重子顶点质量不为零,但如果有这样的质量,它应该位于弦的端点之一。角动量平面(J,M^2)中的重子轨道(包括轻重子、奇异重子和粲重子)在弦端点加上质量时拟合得相当好,其普适斜率为0.95 GeV^-2。我们发现,夸克质量的大部分结果与前面一篇论文中从介子谱中提取的结果一致,其中介子拟合的斜率值为0.90 GeV^-2。在量子径向激发平面(n,M^2)中,我们还发现介子和重子的斜率很好地一致。我们研究了双夸克的味结构,其中我们特别感兴趣的是由多于一个比u和d夸克重的夸克组成的重子。对于这些重子,我们提出了一种方法来检查我们的结果的全息解释。

英文摘要:

We continue our program of describing hadrons as rotating strings with massive endpoints. In this paper we propose models of baryons and confront them with the baryon Regge trajectories. We show that these are best fitted by a model of a single string with a quark at one endpoint and a diquark at the other. This model is preferred over the Y-shaped string model with a quark at each endpoint. We show how the model follows from a stringy model of the holographic baryon which includes a baryonic vertex connected with N_c strings to flavor probe branes. From fitting to baryonic data we find that there is no clear evidence for a non-zero baryonic vertex mass, but if there is such a mass it should be located at one of the string endpoints. The available baryon trajectories in the angular momentum plane (J,M^2), involving light, strange, and charmed baryons, are rather well fitted when adding masses to the string endpoints, with a single universal slope of 0.95 GeV^-2. Most of the results for the quark masses are then found to be consistent with the results extracted from the meson spectra in a preceding paper, where the value of the slope emerging from the meson fits was found to be 0.90 GeV^-2. In the plane of quantum radial excitations, (n,M^2), we also find a good agreement between the meson and baryon slopes. The flavor structure of the diquark is examined, where our interest lies in particular on baryons composed of more than one quark heavier than the u and d quarks. For these baryons we present a method of checking the holographic interpretation of our results.

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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