Soft pattern of Rutherford scattering from heavy target mass expansion  

作　　者：Yu Jia Jia-Yue Zhang 贾宇;张佳玥(Institute of High Energy Physics and Theoretical Physics Center for Science Facilities,Chinese Academy of Sciences,Beijing 100049,China;School of Physics,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]Institute of High Energy Physics and Theoretical Physics Center for Science Facilities,Chinese Academy of Sciences,Beijing 100049,China [2]School of Physics,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Physics C》2025年第3期17-27,共11页中国物理C(英文版)

基　　金：Supported in part by the National Natural Science Foundation of China(11925506,12475090).

摘　　要：We investigate the soft behavior of the tree-level Rutherford scattering process.We consider two types of Rutherford scattering processes:One in which a low-energy massless point-like projectile(say,a spin-1/2 or spin-0 electron)hits a static massive composite target particle carrying various spins(up to spin-2),and one where a slowly-moving light projectile hits a heavy static composite target.For the first type,the unpolarized cross sections in the laboratory frame are found to exhibit universal forms in the first two orders of 1/M expansion yet differ at the next-to-next-to-leading order(though some terms at this order still remain universal or depend on the target spin in a definite manner).For the second type,at the lowest order in electron velocity expansion,through all orders in 1/M,the unpolarized cross section is universal(also not sensitive to the projectile spin).The universality partially breaks down at relative order-v^(2)/M^(2),though some terms at this order are still universal or depend on the target spin in a specific manner.We also employ the effective field theory approach to reproduce the soft behavior of the differential cross sections for when the target particle is a composite spin-1/2 fermion.

关 键 词：Rutherford scattering nucleus structure heavy quark effective theory NRQED 

分 类 号：O57[理学—粒子物理与原子核物理]