He) Reaction
He) Reaction
复制标题
他）反应
DOI：
--
复制
发表时间：
--
期刊：
影响因子：
--
通讯作者：
A. Gillitzer
中科院分区：
文献类型：
--
作者：
R. Hayano;S. Hirenzaki;A. Gillitzer
我们建议用无后坐力（d, 3）反应来制备η-mesic核。这个反应已经被用来观察深束缚态，并且最近被证明是强大的。我们用光势计算了原子核内的η-mesic束缚态，用格林函数法计算了它们的形成截面。然后，我们仔细检查实验的可行性。我们发现用（d, 3 He）反应可以观察到η-介核。我们还提到了研究ω-介核形成的可能性。η介子在原子核中的束缚态（η-mesic核）是迄今尚未在实验中观察到的有趣的对象。η介子是SU(3)伪标量介子中的一员，被认为是自发手性对称破缺的Nambu-Goldstone玻色子之一。从理论上研究了Nambu-Goldstone玻色子的质量起源，即对称破缺模式[1]。由于手性对称性有望在有限密度下部分恢复，因此研究介子的行为，特别是介子在原子核中的质量，是非常有趣的。由于与N *(1535)共振的强耦合，使得η核散射长度以s波部分为主，因此η核光势具有较大的s波部分。因此，通过对η介子核的光谱研究，我们可以期望获得s波势的精确信息，这相当于原子核中η介子的质量位移。我们还期望通过对η核光势的研究，获得核物质中N *(1535)共振性质的新信息。π介子和K介子也是nambugoldstone玻色子，它们在介质中的行为已经从散射和mesic原子数据中得到了相当好的理解。相比之下，关于η介子在介质中性质的实验资料很少。Haider和Liu bbb从理论上提出了η-mesic核的存在。他们系统地研究了η-mesic核态，并提出用（π +, p）反应来形成它们。在这个反应中寻找束缚态的实验尝试导致了否定的结果b[4]。另一方面，发现d(p, 3 He)η反应在阈值处产生η介子的截面很大，并根据准束缚η−3 He体系[6]进行了分析。对于η−4 He体系也存在准束缚态。
We propose to use the recoilless (d, 3 He) reaction to produce η-mesic nuclei. This reaction has been used to observe deeply bound pionic states and proven to be powerful recently. We calculate η-mesic bound states in the nucleus using an optical potential and their formation cross section with the Green function method. Then, we carefully check the experimental feasibility. We find that η-mesic nuclei can be observed experimentally using the (d, 3 He) reaction. We also mention the possibility to study the formation of ω-mesic nuclei. Bound states of η mesons in nuclei (η-mesic nuclei) are interesting objects which have not been observed so far experimentally. The η-meson is a member of the SU(3) nonet of pseudoscalar mesons and believed to be one of the Nambu-Goldstone bosons of spontaneous chiral symmetry breaking. The origin of the mass of the Nambu-Goldstone bosons is studied theoretically in terms of a symmetry breaking pattern[1]. Since chiral symmetry is expected to be partially restored at finite density[2], it is very interesting to study the behavior of mesons, especially their masses, in the nucleus. Since the η-nucleon scattering length is dominated by the s-wave part due to the strong coupling to the N * (1535) resonance, the η-nucleus optical potential has a large s-wave part. Thus by spectroscopic studies of η-mesic nuclei, we can expect to obtain precise information on the s-wave potential, which is equivalent to the mass shift of the η-meson in the nucleus. We also expect to get new information on the properties of the N * (1535) resonance in nuclear matter by studying the η-nucleus optical potential. The in-medium behavior of π and K mesons, which are also Nambu-Goldstone bosons, has been reasonably well understood from scattering as well as mesic atom data. In contrast, there is little experimental information on the in-medium properties of the η meson. Existence of η-mesic nuclei was suggested theoretically by Haider and Liu[3]. They systematically investigated η-mesic nuclear states and proposed to use the (π + , p) reaction for their formation. Experimental attempts to find a bound state in this reaction led to negative results[4]. On the other hand, the cross section for η meson production in d(p, 3 He)η reactions at threshold was found to be large[5] and was analyzed in terms of a quasi-bound η− 3 He system[6]. For the η− 4 He system also the existence of a quasi-bound state …