Virtual Compton scattering off the nucleon at low energies.
Virtual Compton scattering off the nucleon at low energies.
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虚拟康普顿在低能量下散射核子。
DOI：
10.1103/physrevc.54.904
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
J. H. Koch
中科院分区：
文献类型：
--
作者：
S. Scherer;A. Korchin;J. H. Koch
We investigate the low-energy behavior of the four-point Green{close_quote}s function {Gamma}{sup {mu}{nu}} describing virtual Compton scattering off the nucleon. Using Lorentz invariance, gauge invariance, and crossing symmetry, we derive the leading terms of an expansion of the operator in the four-momenta {ital q} and {ital q}{sup {prime}} of the initial and final photon, respectively. The model-independent result is expressed in terms of the electromagnetic form factors of the free nucleon, i.e., on-shell information which one obtains from electron-nucleon scattering experiments. Model-dependent terms appear in the operator at {ital O}({ital q}{sub {alpha}}{ital q}{sub {beta}}{sup {prime}}), whereas the orders {ital O}({ital q}{sub {alpha}}{ital q}{sub {beta}}) and {ital O}({ital q}{sub {alpha}}{sup {prime}}{ital q}{sub {beta}}{sup {prime}}) are contained in the low-energy theorem for {Gamma}{sup {mu}{nu}}, i.e., no new parameters appear. We discuss the leading terms of the matrix element and comment on the use of on-shell equivalent electromagnetic vertices in the calculation of {open_quote}{open_quote}Born terms{close_quote}{close_quote} for virtual Compton scattering. {copyright} {ital 1996 The American Physical Society.}
We investigate the low-energy behavior of the four-point Green{close_quote}s function {Gamma}{sup {mu}{nu}} describing virtual Compton scattering off the nucleon. Using Lorentz invariance, gauge invariance, and crossing symmetry, we derive the leading terms of an expansion of the operator in the four-momenta {ital q} and {ital q}{sup {prime}} of the initial and final photon, respectively. The model-independent result is expressed in terms of the electromagnetic form factors of the free nucleon, i.e., on-shell information which one obtains from electron-nucleon scattering experiments. Model-dependent terms appear in the operator at {ital O}({ital q}{sub {alpha}}{ital q}{sub {beta}}{sup {prime}}), whereas the orders {ital O}({ital q}{sub {alpha}}{ital q}{sub {beta}}) and {ital O}({ital q}{sub {alpha}}{sup {prime}}{ital q}{sub {beta}}{sup {prime}}) are contained in the low-energy theorem for {Gamma}{sup {mu}{nu}}, i.e., no new parameters appear. We discuss the leading terms of the matrix element and comment on the use of on-shell equivalent electromagnetic vertices in the calculation of {open_quote}{open_quote}Born terms{close_quote}{close_quote} for virtual Compton scattering. {copyright} {ital 1996 The American Physical Society.}