Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia.
University of Tuzla, Faculty of Natural Sciences and Mathematics, Univerzitetska 4, 75000 Tuzla, Bosnia and Herzegovina.
Sci Rep. 2017 Mar 27;7:45246. doi: 10.1038/srep45246.
All resonances, from hydrogen nuclei excited by the high-energy gamma rays in deep space to newly discovered particles produced in Large Hadron Collider, should be described by the same fundamental physical quantities. However, two distinct sets of properties are used to describe resonances: the pole parameters (complex pole position and residue) and the Breit-Wigner parameters (mass, width, and branching fractions). There is an ongoing decades-old debate on which one of them should be abandoned. In this study of nucleon resonances appearing in the elastic pion-nucleon scattering we discover an intricate interplay of the parameters from both sets, and realize that neither set is completely independent or fundamental on its own.
所有共振，从深空中高能伽马射线激发的氢核到在大型强子对撞机中发现的新粒子，都应该用相同的基本物理量来描述。然而，有两套截然不同的性质被用来描述共振：极点参数（复极点位置和留数）和 Breit-Wigner 参数（质量、宽度和分支比）。几十年来，人们一直在争论应该放弃哪一个。在这项研究中，我们发现了在弹性π-核子散射中出现的核子共振的参数之间存在着复杂的相互作用，并且意识到这两个参数集都不是完全独立或基本的。
