标题： π介子-核子耦合常数和散射长度的确定 显示英文标题

标题： Determination of the pion-nucleon coupling constant and scattering lengths

摘要： 我们利用来自π介子原子的负电荷π介子质子和π介子氘核散射长度的最新精确测量结果，对正向π介子-核子散射的等矢量GMO求和规则进行了严格评估。 我们推导出带电π介子-核子耦合常数，并仔细考虑了系统不确定性和统计不确定性。 这一确定直接从数据中给出了一个赝标耦合常数为14.11±0.05（统计）±0.19（系统），或一个赝矢耦合常数为0.0783（11）。 该值介于间接方法和从反向中子-质子微分散射截面直接确定的值之间。 我们还利用π介子原子数据，以高精度推导出负电荷π介子-质子和π介子-中子散射长度的相干对称和反对称和。 对称和为0.0012±0.0002（统计）±0.0008（系统），反对称和为0.0895±0.0003（统计）±0.0013（系统），单位为带电π介子质量的倒数。 为了本次分析的需要，我们改进了π介子-氘核散射长度的理论描述。 显示英文摘要

摘要： We critically evaluate the isovector GMO sum rule for forward pion-nucleon scattering using the recent precision measurements of negatively charged pion-proton and pion-deuteron scattering lengths from pionic atoms. We deduce the charged-pion-nucleon coupling constant, with careful attention to systematic and statistical uncertainties. This determination gives, directly from data a pseudoscalar coupling constant of 14.11+-0.05(statistical)+-0.19(systematic) or a pseudovector one of 0.0783(11). This value is intermediate between that of indirect methods and the direct determination from backward neutron-proton differential scattering cross sections. We also use the pionic atom data to deduce the coherent symmetric and antisymmetric sums of the negatively charged pion-proton and pion-neutron scattering lengths with high precision. The symmetric sum gives 0.0012+-0.0002(statistical)+-0.0008 (systematic) and the antisymmetric one 0.0895+-0.0003(statistical)+-0.0013(systematic), both in units of inverse charged pion-mass. For the need of the present analysis, we improve the theoretical description of the pion-deuteron scattering length.