论文部分内容阅读
(全国物理竞赛决赛题)(1)质量不为零的ω介子静止时衰变为三个质量相同的π介子,即ω→3π。讨论每次衰变产生的三个π介子的动能T_1、T_2、T_3可能取的全部值。通常表示每一组动能值(T_1、T_2、T_3)的方法如下:(1)作一个等边三角形A_1A_2A_3,取其高Q为三个π介子的动能之和Q=T_1+T_2+T_3。在三角形内取一点P,令P点到顶点A_1的对边距离为T_1(i=1,2,3)每一点对应一组动能值,可以用P点可能存在的区域来表示。这个区域称为运动学允许区。试在△A_1 A_2 A_2中找ω→3π的运动学允许区(设衰变后π介子的速度比光速小很多)。
(National Physics Competition final question) (1) The non-zero mass of the ω meson decays into three pions of the same mass at rest, ω → 3π. The possible values of the kinetic energy T_1, T_2, T_3 of three pion generated by each decay are discussed. The general method of representing each set of kinetic energy values (T_1, T_2, T_3) is as follows: (1) Make an equilateral triangle A_1A_2A_3 and take the sum of the kinetic energies Q = T_1 + T_2 + T_3 of the high Q as three pions. In the triangle, take a point P, so that the distance from the point P to the vertex A_1 is T_1 (i = 1, 2, 3). Each point corresponds to a group of kinetic energy values, which can be expressed by the area where the P point may exist. This area is called the Kinematics Allowed Area. Try to find the kinematic permissible region of ω → 3π in △ A_1 A_2 A_2 (assuming that the decay p-meson is much slower than the speed of light).