The phenomenon of quartet condensation in the ground state of an isovector pairing Hamiltonian for an even–even N = Z system is investigated. For this purpose we follow the evolution of the ground state from an unperturbed regime up to a strongly interacting one in a formalism of collective pairs. These pairs are those resulting from the diagonalization of the pairing Hamiltonian in a space of two particles coupled to isospin T = 1. The ground state is found to rapidly evolve from a product of distinct T = 0 quartets, each one formed by two of the above pairs, to a condensate of identical quartets built only with the pair corresponding to the lowest energy. This finding establishes a link between the complicated structure of the exact ground state and the simple approximation scheme of the quartet condensation model. The mechanism at the basis of this quartet condensation turns out to be the same which is responsible for the development of a pair cond...

中文翻译：

---

等矢量配对力引起的四方缩合。

研究了偶数偶数N = Z系统的等矢量哈密顿量对的基态四重态凝聚现象。为此目的，我们遵循基态从无扰动政权演变成集体对形式主义中相互作用强烈的政权的演变。这些对是由成对的哈密顿量在对等旋T = 1耦合的两个粒子的空间中的对角线化所产生的对。发现基态从不同的T = 0四元组的乘积快速演化，每个四元组由两个在上述对中，冷凝成相同四重态的冷凝物，仅用对应最低能量的那对构成。这一发现在精确的基态的复杂结构与四重态凝聚模型的简单近似方案之间建立了联系。