AN IMPROVED PARAMETRIZATION OF THE OPTICAL-POTENTIAL FOR PIONIC ATOMS

被引：51

作者：

KONIJN, J ^{[1
]}

DELAAT, CTAM ^{[1
]}

TAAL, A ^{[1
]}

KOCH, JH ^{[1
]}

机构：

[1] UNIV AMSTERDAM,INST THEORET PHYS,AMSTERDAM,NETHERLANDS

来源：

NUCLEAR PHYSICS A | 1990年 / 519卷 / 04期

关键词：

D O I：

10.1016/0375-9474(90)90435-O

中图分类号：

O57 [原子核物理学、高能物理学];

学科分类号：

070202 ;

摘要：

We try to find an improved phenomenological optical potential for pionic atoms in two steps. First, we perform a new fit of the parameters in the standard optical potentials by using a large data base of 140 pionic atom data. A chi-2 is obtained that is substantially lower than with any previous parameter set. In a second step, we extend the number of parameters by using a more general form for the terms quadratic in the nuclear density. This extended version yields a reduction of the chi-2 by about a factor of two. The new fit includes a good description of shifts and widths of the deeply bound 3d orbits in heavy nuclei such as Ta-181, Re(nat), Pt(nat), Au-197, Pb-208 and Bi-209. The value of the additional parameters in the extended version are difficult to interpret in the context of the chosen form of the optical potential and indicate that higher-order effects play a role.

引用

页码：773 / 804

页数：32

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