Light quark mass difference and isospin breaking in electromagnetic pion production

被引：40

作者：

Bernstein, AM ^{[1
]}

机构：

[1] MIT, Dept Phys, Cambridge, MA 02139 USA

[2] MIT, Nucl Sci Lab, Cambridge, MA 02139 USA

来源：

PHYSICS LETTERS B | 1998年 / 442卷 / 1-4期

关键词：

D O I：

10.1016/S0370-2693(98)01257-X

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

It is demonstrated that there is a dynamic isospin breaking effect in the near threshold gamma*N --> pi N reaction due to the mass difference of the up and down quarks, which also causes isospin breaking in the pi N system. The photopion reaction is affected through final state pi N interactions (formally implemented by unitarity and time reversal invariance). It is also demonstrated that the near threshold gamma N --> pi N reaction is a practical reaction to measure isospin breaking in the pi N system, which was first predicted by Weinberg about 20 years ago but has never been experimentally tested. (C) 1998 Published by Elsevier Science B.V. All rights reserved.

引用

页码：20 / 27

页数：8

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