Internal structure of exotic hadrons by high-energy exclusive reactions
Internal structure of exotic hadrons by high-energy exclusive reactions
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DOI：
10.7566/jpscp.8.022005
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发表时间：
2014-10
期刊：
影响因子：
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通讯作者：
H. Kawamura;S. Kumano;T. Sekihara
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文献类型：
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作者：
H. Kawamura;S. Kumano;T. Sekihara
我们建议利用高能排他反应来探测奇异强子候选者的内部结构。首先，微扰QCD的组分计数规则可以用来寻找奇异强子候选者的内部组态。这是因为参与排他反应的组分数（$n$）是通过大动量转移时截面$d\sigma/dt \propto 1/s^{n-2}$的标度行为来确定的，其中$s$是质心能量的平方。作为一个例子，我们证明了$\Lambda \，（1405）$的内部结构应该被发现，例如，通过反应$\pi^- + p \到K^0 + \Lambda（1405）$。第二，奇异强子候选者的内部结构，应该用强子层析术与广义部分子分布（GPD）和广义分布振幅（GDA）在排他性反应。奇异的性质应该反映在GPD中，GPD包含两个因素，纵向部分子分布的组分计数规则和横向形状因子的强子大小建议。在正负电子湮灭中，GDA应该通过双光子过程$\gamma^* \gamma \to h\bar h$来研究，例如$h=f_0$或$a_0$。由于GDA包含的信息上的一个类时的形状因子，奇异的性质应该通过研究$h\bar h$不变的质量依赖的横截面。奇异强子候选者的内部结构应该通过在J-PARC和KEKB等设施上的排他反应来澄清。
We propose to use high-energy exclusive reactions for probing internal structure of exotic hadron candidates. First, the constituent counting rule of perturbative QCD can be used for finding internal configurations of an exotic hadron candidate. It is because the number of constituents ($n$), which participate in the exclusive reaction, is found by the scaling behavior of the cross section $d\sigma/dt \propto 1/s^{n-2}$ at large momentum transfer, where $s$ is the center-of-mass energy squared. As an example, we show that the internal structure of $\Lambda \, (1405)$ should be found, for example, by the reaction $\pi^- + p \to K^0 + \Lambda (1405)$. Second, the internal structure of exotic hadron candidates should be investigated by hadron tomography with generalized parton distributions (GPDs) and generalized distribution amplitudes (GDAs) in exclusive reactions. Exotic nature should be reflected in the GPDs which contain two factors, longitudinal parton distributions as indicated by the constituent counting rule and transverse form factors as suggested by the hadron size. The GDAs should be investigated by the two-photon process $\gamma^* \gamma \to h\bar h$, for example $h=f_0$ or $a_0$, in electron-positron annihilation. Since the GDAs contain information on a time-like form factor, exotic nature should be found by studying the $h\bar h$ invariant mass dependence of the cross section. The internal structure of exotic hadron candidates should be clarified by the exclusive reactions at facilities such as J-PARC and KEKB.