Department of Physics, University of Pisa, 56127 Pisa, Italy and INFN-Pisa, 56127 Pisa, Italy.
Phys Rev Lett. 2013 May 10;110(19):192503. doi: 10.1103/PhysRevLett.110.192503.
The astrophysical S factor for proton-proton weak capture is calculated in chiral effective field theory over the center-of-mass relative-energy range 0-100 keV. The chiral two-nucleon potential derived up to next-to-next-to-next-to leading order is augmented by the full electromagnetic interaction including, beyond Coulomb, two-photon and vacuum-polarization corrections. The low-energy constants entering the weak current operators are fixed so as to reproduce the A=3 binding energies and magnetic moments and the Gamow-Teller matrix element in tritium β decay. Contributions from S and P partial waves in the incoming two-proton channel are retained. The S factor at zero energy is found to be S(0)=(4.030±0.006)×10(-23) MeV fm(2), with a P-wave contribution of 0.020×10(-23) MeV fm(2). The theoretical uncertainty is due to the fitting procedure of the low-energy constants and to the cutoff dependence.
在质心系相对能量范围为 0-100keV 的情况下，我们在手征有效场理论中计算了质子-质子弱俘获的天体物理 S 因子。我们将截至次领头阶的手征两核势与包括库仑势之外的双光子和真空极化修正的完整电磁相互作用相结合。弱电流算符中的低能常数被固定，以便重现 A=3 束缚能和磁矩以及氚β衰变中的 Gamow-Teller 矩阵元。保留了入射两质子通道中 S 和 P 部分波的贡献。在零能量下，S 因子为 S(0)=(4.030±0.006)×10(-23) MeV fm(2)，其中 P 波贡献为 0.020×10(-23) MeV fm(2)。理论不确定性来自于低能常数的拟合过程和截止依赖。
