通过基矢光前量子化方法对π介子的研究

为研究介子的性质,通过基矢光前量子化方法获得介子的光前波函数。基失光前量子化是一种在哈密顿量体系下基于量子场论的非微扰方法。在哈密顿量中我们考虑了动能项、基于全息色动力学的横向禁闭势、与横向禁闭势互补的纵向禁闭势和基于QCD的夸克-胶子相互作用。我们的基矢空间包括最低阶的两个Fock空间,即领头阶■与次领头阶■。根据所得的光前波函数我们计算了介子衰变常数以及(基于领头Fock空间的)电磁半径,这些结果与粒子数据手册(PDG)上的结果相近。此外,我们计算了(基于领头Fock空间的)介子部分子分布,QCD演化后,与原先的结果相近(蓝江山等,Phys Rev Lett,2 019,122:172 001.),能够很好地描述费米国家实验室(FNAL)与欧洲核子中心(CERN)的实验数据。

Contents

We study the properties of the pion through the light-front wave function (LFWF) obtained from the basis light-front quantization (BLFQ) approach. BLFQ is a nonperturbative approach to quantum field theory based on the Hamiltonian formalism. Our Hamiltonian contains the kinetic energy terms, a transverse confining potential motivated by holographic quantum chromodynamics (QCD), a complementary longitudinal confining potential, and the quark-gluon interactions based on QCD. Our basis space includes the lowest two Fock sectors, namelyand. The obtained pion decay constant and electromagnetic radius (at the leading order Fock sector) are comparable to those from the particle data group (PDG). Next, we calculate the parton distribution function (PDF) of the pion based on the leading Fock sector LFWF. After QCD evolution, the resulting PDF is similar to the previous result (Lan et al., Phys Rev Lett, 2019, 122: 172001.), and agrees with the experimental data from the Fermi National Accelerator Laboratory (FNAL), as well as those from the European Organization for Nuclear Research (CERN).