Scalar and fermion on-shell amplitudes in generalized Higgs effective field theory
Scalar and fermion on-shell amplitudes in generalized Higgs effective field theory
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DOI：
10.1103/physrevd.104.015001
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发表时间：
2021-02
影响因子：
5
通讯作者：
R. Nagai;M. Tanabashi;K. Tsumura;Yoshiki Uchida
中科院分区：
文献类型：
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作者：
R. Nagai;M. Tanabashi;K. Tsumura;Yoshiki Uchida
为了计算超标准模型粒子的散射振幅，有效场论中必须包含超标准模型粒子。我们制定了希格斯有效场论的扩展，其中包含任意数量的标量场和费米子场与任意的电荷和色电荷。BSM Higgs扇区是用非线性sigma模型描述的，与自发电弱对称性破缺一致。手征顺序计数规则安排一致的循环展开。首阶拉格朗日量按照手征序计数规则雅阁。我们用几何语言来描述粒子的相互作用。通过在标量/费米子场空间中只用协变量描述壳层上散射振幅，解决了有效拉格朗日量中的参数化冗余问题。我们引入了一个有用的坐标（法向坐标），它大大简化了壳层振幅的计算。我们发现散射振幅的高能行为决定了标量/费米子场空间中的“曲率张量”。大量的旋量波函数形式主义被证明是有用的壳层螺旋度振幅的计算。
Beyond standard model (BSM) particles should be included in effective field theory in order to compute the scattering amplitudes involving these extra particles. We formulate an extension of Higgs effective field theory which contains arbitrary number of scalar and fermion fields with arbitrary electric and chromoelectric charges. The BSM Higgs sector is described by using the non-linear sigma model in a manner consistent with the spontaneous electroweak symmetry breaking. The chiral order counting rule is arranged consistently with the loop expansion. The leading order Lagrangian is organized in accord with the chiral order counting rule. We use a geometrical language to describe the particle interactions. The parametrization redundancy in the effective Lagrangian is resolved by describing the on-shell scattering amplitudes only with the covariant quantities in the scalar/fermion field space. We introduce a useful coordinate (normal coordinate), which simplifies the computations of the on-shell amplitudes significantly. We show the high energy behaviors of the scattering amplitudes determine the "curvature tensors" in the scalar/fermion field space. The massive spinor-wavefunction formalism is shown to be useful in the computations of on-shell helicity amplitudes.