Dispersion analysis of the strange vector form factors of the nucleon
Dispersion analysis of the strange vector form factors of the nucleon
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DOI：
10.1103/physrevc.56.510
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发表时间：
1996-07
影响因子：
3.1
通讯作者：
H. Forkel
中科院分区：
文献类型：
--
作者：
H. Forkel
We analyze the nucleon matrix element of the strange quark vector current in a nucleon-model-independent dispersive approach with input from the current world data set for the isoscalar electromagnetic form factors. The update of Jaffe{close_quote}s minimal three-pole {ital Ansatz} for the spectral functions yields a 40{percent} larger (Sachs) strangeness radius (r{sub s}{sup 2}){sub Sachs}=0.20 fm{sup 2} and a by 20{percent} reduced magnitude of the strangeness magnetic moment {mu}{sub s}={minus}0.26. In the pole approximation these values are shown to be upper bounds. After extending the {ital Ansatz} in order to implement the asymptotic QCD momentum dependence (which the three-pole form factors cannot reproduce), we find the magnitude of the three-pole results reduced by up to a factor of 2.5. The signs of the leading moments originate primarily from the large {phi}-meson couplings and are generic in the pole approximation. {copyright} {ital 1997} {ital The American Physical Society}
We analyze the nucleon matrix element of the strange quark vector current in a nucleon-model-independent dispersive approach with input from the current world data set for the isoscalar electromagnetic form factors. The update of Jaffe{close_quote}s minimal three-pole {ital Ansatz} for the spectral functions yields a 40{percent} larger (Sachs) strangeness radius (r{sub s}{sup 2}){sub Sachs}=0.20 fm{sup 2} and a by 20{percent} reduced magnitude of the strangeness magnetic moment {mu}{sub s}={minus}0.26. In the pole approximation these values are shown to be upper bounds. After extending the {ital Ansatz} in order to implement the asymptotic QCD momentum dependence (which the three-pole form factors cannot reproduce), we find the magnitude of the three-pole results reduced by up to a factor of 2.5. The signs of the leading moments originate primarily from the large {phi}-meson couplings and are generic in the pole approximation. {copyright} {ital 1997} {ital The American Physical Society}