Дикварковое состояние a_0 (980) мезона и вычисление его ширины распада в ковариантной модели кварков

A.N. Issadykov; M.A. Ivanov; S.A. Zhaugasheva; G.S. Nurbakova; G.G. Saidullaeva; B.A. Mukushev

Authors

A.N. Issadykov L.N. Gumilev Eurasian National University, Astana, Kazakhstan
M.A. Ivanov Joint Institute for Nuclear Research, Dubna, Russia
S.A. Zhaugasheva Al-Farabi Kazakh National University, Kazakstan, Almaty
G.S. Nurbakova Al-Farabi Kazakh National University, Kazakstan, Almaty
G.G. Saidullaeva Al-Farabi Kazakh National University, Kazakstan, Almaty
B.A. Mukushev Shakarim State University, Semey, Kazakhstan

Keywords:

diquark, covariant quark model, scalar meson, decay width, tetraquark

Abstract

In paper we study the quark structure and mechanism of the formation of a а₀(980) meson’s bound state. Recently, the quark structure of the scalar meson а₀(980) arouses great interest. Therefore, in our work we calculated the width of radiative decays for diquark states of а₀(980) meson at different values of meson’s size in the covariant quark model, which is the effective quantum field approach to hadron interactions based on lagrangian interaction of hadrons with their constituent quarks. In this model there are no threshold singularity corresponding to the birth of the quarks due to introducing the infrared cutoff in the space of Fock-Schwinger parameters. The model has several free parameters: the mass of constituent quarks, the infrared cutoff parameter and the parameter that describe effective size of hadrons.The results obtained differ from the experimental data on the order. Thus assume that а₀(980) meson is tetraquark system.