A Gaussian-mixture approximation of the Bethe–Heitler model of electron energy loss by bremsstrahlung
A Gaussian-mixture approximation of the Bethe–Heitler model of electron energy loss by bremsstrahlung
复制标题
轫致辐射电子能量损失的 Bethe-Heitler 模型的高斯混合近似
DOI：
10.1016/s0010-4655(03)00292-3
复制
发表时间：
2003
影响因子：
6.3
通讯作者：
R. Frühwirth
中科院分区：
文献类型：
--
作者：
R. Frühwirth
电子的韧致辐射能量损失的分布与高斯分布有很大的不同。如果在航迹重建中要考虑韧致辐射的能量损失，则其分布必须用高斯混合来近似，以便(广义)卡尔曼滤波可以使用它。这一分布取自韧致辐射的Bethe-Heitler模型，该模型假定韧致辐射光谱可以用一个约化的量来描述，而与电子能量无关。在这种情况下，混合物的参数可以仅作为材料量的函数来参数化。给出了一组分到六组分的近似混合物的计算方法，并给出了近似质量的结果。最后，用五次多项式的形式得到了所需的混合参数。
The distribution of the energy loss by bremsstrahlung of electrons is very different from a Gaussian one. If the energy loss by bremsstrahlung is to be taken into account during track reconstruction, its distribution has to be approximated by a Gaussian mixture so that it can be used by a (generalized) Kalman filter. The distribution is taken from the Bethe–Heitler model of bremsstrahlung, which assumes that the bremsstrahlung spectrum can be described in terms of a reduced quantity, independent of the electron energy. In this case the parameters of the mixture can be parameterized as a function of the amount of material only. The algorithm for computing the approximating mixtures with one to six components is described, and results on the quality of the approximation are shown. Finally, the required parameterizations of the mixtures are obtained in terms of 5th order polynomials.