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arXiv 1306.4671hep-ph
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Charmonium Exotic States

Charmonium Exotic States

Raphael M. Albuquerque

摘要:

本文利用QCD求和规则方法研究了粲偶素Y(3930),Y(4140),X(4350),Y(4260),Y(4360)和Y(4660)共振态的性质。有一个强有力的证据表明,这些国家有非常规(或异国情调)的强子结构,因为它们各自的质量和衰变通道观察到的实验是不一致的预期与传统的粲偶素状态。同样的现象也发生在bottomonium扇区,最近观察到的Yb(10890)和Yb(11020)等新态可能表明存在新的bottomonium奇异态。通过这种方式,可以验证Y(4140)态可以被描述为D*sD*s(0++)分子态,或者甚至被描述为D*sD*s(0++)和D*D*(0++)分子态的混合物。对于Y(3930)和X(4350)状态,两者都不能分别描述为D*D*(0++)和D*sD* s 0(1-+)。从求和规则的观点来看,Y(4660)态可以被描述为一个π ' f0(980)分子态。对bottomonium扇区的扩展是以一种简单的方式完成的,以证明Yb ' f0(980)分子态是描述Yb(10890)态结构的一个很好的候选。在下文中,人们使用求和规则方法估计奇异的类Bc分子态的质量,其中这些新的奇异态将对应于D(*)和B(*)介子的束缚态。所有这些质量预测都可以(或不可以)在不久的将来在LHC的实验中进行检查。本文介绍了一个用双比求和规则方法研究QCD中重子质量的大型研究。对于未观测到的重子,有一个(Qqq)和两个(QQq)重夸克的结果将是一个很好的测试的求和规则的方法在预测其质量的能力。

英文摘要:

In this thesis, the QCD sum rules approach has been used to study the nature of the following charmonium resonances: Y(3930), Y(4140), X(4350), Y(4260), Y(4360) and Y(4660). There is a strong evidence that these states have non-conventional (or exotic) hadronic structures since their respective masses and decay channels observed experimentally are inconsistent with expected for a conventional charmonium state. The same phenomenon occurs on the bottomonium sector, where new states like Yb(10890) and Yb(11020) observed recently could indicate the existence of new bottomonium exotic states. In this way, one verifies that the Y(4140) state could be described as a D*sD*s (0++) molecular state or even as a mixture of D*sD*s (0++) and D*D* (0++) molecular states. For the Y(3930) and X(4350) states, both cannot be described as a D*D* (0++) and D*sD*s0 (1-+), respectively. From the sum rule point of view, the Y(4660) state could be described as a ψ' f0(980) molecular state. The extension to the bottomonium sector is done in a straightforward way to demonstrate that the Υ' f0(980) molecular state is a good candidate for describing the structure of the Yb(10890) state. In the following, one estimates the mass of the exotic Bc-like molecular states using the sum rule approach, where these new exotic states would correspond to bound states of D(*) and B(*) mesons. All of these mass predictions could (or not) be checked in a near future experiments at LHC. A large study using the Double Ratio of Sum Rules approach has been evaluated for studying the heavy baryon masses in QCD. The obtained results for the unobserved heavy baryons, with one (Qqq) and two (QQq) heavy quarks will be an excellent test for the capability of the sum rule approach in predicting their masses.

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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