论文标题
轻量量化中的t和真空气泡
Tadpoles and vacuum bubbles in light-front quantization
论文作者
论文摘要
我们开发了一种方法，该方法可以将真空过渡可能包括在光线计算中。这允许t的贡献对于对称性效应至关重要，但由于标准的轻度计算而缺少。这些过渡还决定了非平凡的真空和从真空气泡到物理状态的贡献。在非扰动计算中，这些单独的贡献类（t和气泡）无法过滤；取而代之的是，我们调节气泡并从物理状态的特征力中减去真空能量。关键是用有限宽度的模型函数替换动量支持的三角洲函数；宽度成为调节器，并在减法后将其删除。这种方法在自由标量理论，淬火标量Yukawa理论以及有限的Fock空间截断中说明了$ ϕ^4 $理论。
We develop a method by which vacuum transitions may be included in light-front calculations. This allows tadpole contributions which are important for symmetry-breaking effects and yet are missing from standard light-front calculations. These transitions also dictate a nontrivial vacuum and contributions from vacuum bubbles to physical states. In nonperturbative calculations these separate classes of contributions (tadpoles and bubbles) cannot be filtered; instead, we regulate the bubbles and subtract the vacuum energy from the eigenenergy of physical states. The key is replacement of momentum-conserving delta functions with model functions of finite width; the width becomes the regulator and is removed after subtractions. The approach is illustrated in free scalar theory, quenched scalar Yukawa theory, and in a limited Fock-space truncation of $ϕ^4$ theory.
