Effective Field Theories from Soft Limits of Scattering Amplitudes.
Effective Field Theories from Soft Limits of Scattering Amplitudes.
复制标题
来自散射幅度软极限的有效场论。
DOI：
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发表时间：
2014
影响因子：
8.6
通讯作者：
J. Trnka
中科院分区：
文献类型：
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作者：
C. Cheung;K. Kampf;J. Novotný;J. Trnka
我们从纯粹由洛伦兹不变性、因式分解、导数的固定幂次计数顺序和振幅在软极限中消失的固定顺序构造的壳上散射振幅推导出标量有效场理论——拉格朗日理论、对称性理论和所有理论。这些约束在振幅中留下了自由参数，这些参数是著名理论的耦合常数：南布-戈德斯通玻色子，狄拉克-玻生-因菲尔德标量和伽利略内移对称性。此外，软极限意味着诺特电流的条件，这些条件可以反向推导出每个理论的拉格朗日量。我们根据两个数字对所有标量有效场论进行了自然分类，这两个数字编码了相应振幅的导数幂计数和软行为。在没有一致振幅的情况下，相应的理论不存在。
We derive scalar effective field theories-Lagrangians, symmetries, and all-from on-shell scattering amplitudes constructed purely from Lorentz invariance, factorization, a fixed power counting order in derivatives, and a fixed order at which amplitudes vanish in the soft limit. These constraints leave free parameters in the amplitude which are the coupling constants of well-known theories: Nambu-Goldstone bosons, Dirac-Born-Infeld scalars, and Galilean internal shift symmetries. Moreover, soft limits imply conditions on the Noether current which can then be inverted to derive Lagrangians for each theory. We propose a natural classification of all scalar effective field theories according to two numbers which encode the derivative power counting and soft behavior of the corresponding amplitudes. In those cases where there is no consistent amplitude, the corresponding theory does not exist.