重味重子分子态的唯象研究

Molecular states composed of hadrons are allowed by Quantum chromodynamics (QCD). Recently, more and more possible molecular states have been observed in experiments. It is well known that the deuteron is a bound state of a proton and neutron. Since a heavy baryon at least contains one heavy quark, its large mass reduces its kinetic energy and helps the formation of the bound states. The existence and properties of molecular states composed of heavy baryons will be investigated in the Bethe-Salpeter (BS) equation approach. In the diquark picture, we will establish the BS equation for heavy baryons with the aid of the heavy quark symmetry. The BS wave functions and the masses of the heavy baryons will be given. Then the BS equation for the molecular state composed of heavy baryons will be established. The interaction kernel will be derived from chiral perturbation theory, which respects both the chiral symmetry and the heavy quark symmetry. After solving the BS equation, the mass spetra and the decay widths of the possible molecular states composed of heavy baryons will be given. Our investigation is closely related to experiments. Our results will contribute to understanding QCD theory and provide theoretical support for experiments.

强子的分子束缚态是量子色动力学理论允许存在的新强子态之一。近年来，实验上发现了越来越多的可能的分子束缚态。众所周知，氘核是由质子和中子构成的束缚态。重味重子由于质量较大（含有重夸克），动能较小，从而有助于构成分子束缚态。我们将利用Bethe-Salpeter（BS）方程研究由重味重子构成分子束缚态的可能性和性质。我们将首先在双夸克图像下利用重夸克对称性建立重味重子的BS方程并求解得到相应的BS波函数以及重子的质量。然后将建立由重味重子构成的分子束缚态的BS方程。其中，BS方程的相互作用核将由手征微扰论的拉氏量提供，同时满足手征对称性和重夸克对称性。我们将通过求解BS方程，讨论重味重子构成分子束缚态的可能性以及相应的质量谱和衰变宽度等。研究结果与实验密切相关，将有利于深入理解量子色动力学理论，并为实验提供理论支持。

强子物理的研究是粒子物理中的重要领域。随着LHC的运行，使得这一领域的研究更加迫切。本项目重点研究了由重味重子构成分子束缚态的可能性和性质。我们在双夸克图像下利用重夸克对称性研究了重味重子的性质并讨论了重味重子构成分子束缚态的可能性以及相应的质量谱和衰变宽度等。同时，我们对中子星的性质，矢量介子及其激发态的性质，以及微扰QCD中的CP破坏做了一些有意义的工作。研究结果与实验密切相关，将有利于深入理解量子色动力学理论，并为实验提供理论支持。