论文标题
针对$ q \ bar q q \ bar q $ -Quark Systems的弦描述
Towards a Stringy Description for the $Q\bar Q q\bar q$-Quark System
论文作者
论文摘要
对于两种光口味的情况，我们提出了一个由一个重的夸克和一个轻夸克对制成的系统的杂片描述，目的是探索两个较重的夸张夸克 - 夸克 - 对夸克 - 对夸克对的效果。我们的分析揭示了与字符串重新连接，断裂和灭绝的三个关键分离。特别是，对于基态潜力，仅弦重新连接的过程就很重要。我们发现，四夸克州在小分离下对第一个激发状态的潜力做出了主要的贡献，这与$ qq \ bar q \ bar q $ quark System的差异很大，在该系统中，它对基础状态的潜力确实如此。另一个很大的区别是完整的diquark图片$ [qq] [\ bar q \ bar q] $而不是部分图片$ qq [\ bar q \ bar q] $用于Tetraquark State。另一方面，在下面可以将系统歼灭的尺度视为紧凑型tetraquarks，在两种情况下都非常接近，如果现象学规则$ e_ {qq} = \ frac {1} {1} {2} {2} {q \ bar q} $持有。对于与晶格QCD一致的筛选长度也是如此。
For the case of two light flavors we propose the stringy description of the system made of one heavy and one light quark-antiquark pair, with the aim of exploring the two lower-lying Born-Oppenheimer potentials as a function of a separation of the heavy quark-antiquark pair. Our analysis reveals three critical separations related to the processes of string reconnection, breaking and junction annihilation. In particular, for the ground state potential only the process of string reconnection matters. We find that a tetraquark state makes the dominant contribution to the potential of the first excited state at small separations, and this is the big difference with the $QQ\bar q\bar q$-quark system where it does so to the ground state potential. Another big difference is the emergence of the full diquark picture $[Qq][\bar Q\bar q]$ rather than the partial picture $QQ[\bar q\bar q]$ for the tetraquark state. On the other hand, the scales of string junction annihilation, below which the systems can be thought of mainly as the compact tetraquarks, are very close for both cases and become almost the same if the phenomenological rule $E_{QQ}=\frac{1}{2} E_{Q\bar Q}$ holds. The same is also true for the screening lengths whose values are in agreement with lattice QCD.
