Physics of Atomic Nuclei ( IF 0.3 ) Pub Date : 2020-10-13 , DOI: 10.1134/s1063778820050117 M. V. Egorov
Abstract
The coherent photoproduction of \(\pi^{0}\pi^{0}\) and \(\pi^{0}\eta\) on nuclei in the mass-number region of \(A\leqslant 7\) is studied systematically over the range between the threshold and the laboratory photon energy of \(E_{\gamma}=2\) GeV. The amplitude for photoproduction on nuclei is constructed on the basis of the impulse approximation with allowance for a number of processes responsible for meson–nucleus final-state interaction. The pion-rescattering processes \(\pi N\to\pi N\) and \(\pi N\to\eta N\) occurring on spectator nucleons, \(\pi^{+/-}\pi^{0}\pi^{0}\) and \(\pi^{+/-}\pi^{0}\eta\) production followed by \(\pi^{+/-}\) absorption by spectator nucleons, and three-body \(\pi\)–NN and \(\eta\)–NN interactions are described for the first time within a unified microscopic approach.
中文翻译:
在光核上中性伪标量介子$$ \ boldsymbol {\ pi ^ {0} \ pi ^ {0}} $$和$$ \ boldsymbol {\ pi ^ {0} \ eta} $$在光核上的相干光产生
摘要
\(\ pi ^ {0} \ pi ^ {0} \)和\(\ pi ^ {0} \ eta \)在\(A \ leqslant 7 \)的质量数区域上的相干光产生在阈值和\(E _ {\ gamma} = 2 \) GeV的实验室光子能量之间的范围内,系统地研究了Sn。原子核上光产生的幅度是基于脉冲近似法构造的,并考虑了介子-原子核最终态相互作用的许多过程。pion散射过程\(\ pi N \ to \ pi N \)和\(\ pi N \ to \ eta N \)发生在旁观者核子上(\(\ pi ^ {+/-} \ pi ^ {0 } \ pi ^ {0} \)和\(\ pi ^ {+/-} \ pi ^ {0} \ eta \)生产观众核子对\(\ pi ^ {+/-} \)的吸收,以及三体\(\ pi \) – NN和\(\ eta \) – NN相互作用是首次在统一的微观方法中进行描述。