Rudjer Bošković Institute, Bijenička 54, HR-10000 Zagreb, Croatia.
Phys Rev Lett. 2013 Sep 13;111(11):112004. doi: 10.1103/PhysRevLett.111.112004.
We show that a slightly modified Breit-Wigner formula can successfully describe the total cross section even for the broad resonances, from the light ρ(770) to the heavy Z boson. In addition to the mass, width, and branching fraction, we include another resonance parameter that turns out to be directly related to the pole residue phase. The new formula has two mathematically equivalent forms: one with the pole and the other with the Breit-Wigner parameters.
我们表明，一个略有修改的 Breit-Wigner 公式可以成功地描述总截面，即使对于从轻 ρ(770)到重 Z 玻色子的宽共振也是如此。除了质量、宽度和分支比之外，我们还包括另一个与极点残数相位直接相关的共振参数。新公式有两种数学上等效的形式：一种带有极点，另一种带有 Breit-Wigner 参数。
