Single-pole nature of Λ(1405) and structure of K⁻pp

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• 作者：Yoshinori Akaishi ; Toshimitsu Yamazaki ; Mitsuaki Obu ; Masanobu Wada
• 关键词：Kaonic nucleus ; super-strong nuclear force ; single pole of &#x39b ; (1405)
• 刊名：Nuclear Physics A
• 出版年：2010
• 出版时间：1 April 2010
• 年：2010
• 卷：835
• 期：1-4
• 页码：67-74
• 全文大小：661 K

文摘

We have studied the structure of K⁻pp by solving this system in a variational treatment, starting from Ansatz that Λ(1405) is a K⁻p quasi-bound state, Λ^* with mass 1405 MeV/c². The structure of K⁻pp reveals a molecular feature, namely, the K⁻ in an “atomic center”, Λ^*, plays a key role in producing strong covalent bonding with the other proton. Deeply bound nuclear systems are formed by this “super-strong” nuclear force due to migrating real bosons, , a la Heitler-London-Heisenberg, which overcompensates the stiff nuclear incompressibility. Theoretical background of the Λ(1405) Ansatz is discussed in connection with the double-pole picture of Λ(1405) based on chiral SU(3) dynamics. Detailed analysis reveals single-pole nature of the observable Λ(1405). There are two kinds of Σπ invariant masses experimentally observable, the usual T₂₂ invariant mass and the conversion T₂₁ invariant mass. It is of virtual importance to determine whether the Λ^* mass is 1405 MeV or 1420 MeV. The T₂₁ invariant mass from K⁻ absorption at rest in deuteron can provide decisive information about this Λ^* mass problem.