τ vector and axial vector spectral functions in the extended linear sigma model

FAIR Next Generation ScientistS 2014

Habersetzer, A.^1 ; Giacosa, F.^1,2

Institut für Theoretische Physik, Goethe-Universität, Max-von-Laue-Str. 1, Frankfurt

60438, Germany^1

Institute of Physics, Jan Kochanowski University, Kielce

25-406, Poland^2

关键词: Axial vector;    Electroweak interactions;    Line shape;    Nonresonant;    Sigma model;    Spectral function;    W bosons;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/599/1/012011/pdf
DOI  :  10.1088/1742-6596/599/1/012011

来源: IOP

【 摘 要 】

The extended linear sigma model describes the vacuum phenomenology of scalar, pseudoscalar, vector and axial-vector mesons at energies1 GeV. We combine the chiral U(2)L× U(2)Rsymmetry of this model with a local SU(2)L× U(1)Ysymmetry and obtain a gauge invariant effective description for electroweak interaction of hadrons in the vacuum. Vector and axial-vector spectral functions can be described well by two intermediate resonances ρ and a1. They are implemented into this model as chiral partners and yield the predominant contributions to both spectral functions. However, the contributions that arise from the non resonant decay channels of the weak charged W bosons are essential for reproducing the lineshapes of the spectral functions.