摘要
我们为 neutrondeuteron 的计算使用有效的地理论(水蜥) 在很低的精力的放射的俘获。我们在场这里水蜥的使用计算一低精力相片原子在在直到到领先的顺序的 next-to-next 的热中子精力的三身体的系统，光子极化参数和 foreaft 不对称现象看得见(N <SUP>2</SUP > LO ) ，与电的四极贡献的包括。总共的光子极化参数被发现是 R <SUB > c </SUB>= 0.421 ?
We use effective field theory （EFT） for the calculation of neutron-deuteron radiative capture at very low energies. We present here the use of EFT to calculate a low-energy photo-nuclear observable in three-body systems, the photon polarization parameter and and fore-aft asymmetry at thermal neutron energies up to next-to-next to leading order （N2 LO）, with inclasion of the electric quadrupole contribution. The photon polarization parameter in total is found to be Rc = -0.421±0.003 and is in good agreement with the other modern theoretical calculations based on modern nucleon-nucleon potentials. In comparison with our previous work, a satisfactory agreement with the available experimental data is found by inclusion of the electric quadrupole contribution.
