Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA.
Phys Rev Lett. 2013 Jul 19;111(3):032502. doi: 10.1103/PhysRevLett.111.032502.
We outline a general method for computing nuclear capture reactions on the lattice. The method consists of two major parts. In this study we detail the second part which consists of calculating an effective two-body capture reaction on the lattice at finite volume. We solve this problem by calculating the two-point Green's function using an infrared regulator and the capture amplitude to a two-body bound state. We demonstrate the details of this method by calculating on the lattice the leading M1 contribution to the radiative neutron capture on proton at low energies using pionless effective field theory. We find good agreement with exact continuum results. The approach we outline here can be used in a wide range of applications including few-body reactions in cold atomic systems and hadronic reactions in lattice quantum chromodynamics.
我们概述了一种在格点上计算核俘获反应的通用方法。该方法由两大部分组成。在本研究中，我们详细介绍了第二部分，即在有限体积上计算有效两体俘获反应。我们通过使用红外调节器和俘获振幅来计算两点格林函数来解决这个问题，以获得两体束缚态。我们通过使用无π有效场理论在格点上计算低能质子辐射中子俘获的主导 M1 贡献，展示了这种方法的细节。我们发现与精确连续体结果吻合良好。我们在这里概述的方法可用于广泛的应用，包括冷原子系统中的少体反应和格点量子色动力学中的强子反应。
