Unstable particles near threshold
Unstable particles near threshold
复制标题
接近阈值的不稳定粒子
DOI：
10.3938/jkps.69.16
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发表时间：
2015
影响因子：
0.6
通讯作者：
H. Kim
中科院分区：
文献类型：
--
作者：
Dongjin Chway;T. Jung;H. Kim
我们探索不稳定粒子的物理学，当母粒子的质量大约是它的子粒子质量的总和。在这种情况下，用于窄宽度近似的常规波函数重整化因子定义不清。我们提出了一个简单的解决方案，允许使用窄宽度近似，通过定义波函数重整化因子和分支比在谱密度方面。我们通过计算希格斯门户模型中的横截面来测试新的定义，并获得了显着的改进。同时，不稳定粒子没有单一的衰减宽度，在所有时间尺度上都发生非指数衰减。
We explore the physics of unstable particles when the mother particle’s mass is approximately the sum of the masses of its daughter particles. In this case, the conventional wave function renormalization factor used for the narrow width approximation is ill-defined. We propose a simple resolution of the problem that allows the use of the narrow width approximation by defining the wave function renormalization factor and the branching ratio in terms of the spectral density. We test new definitions by calculating the cross section in the Higgs portal model and a significant improvement is obtained. Meanwhile, no single decay width can be assigned to the unstable particles and non-exponential decay occurs at all time scales.