Theoretical Studies of Hadronic and Nuclear Dynamics

我们的研究重点是研究核-强子动力学，特别强调它与量子色动力学（QCD）的关系，夸克和胶子的基本理论。特别感兴趣的是研究手性对称性的作用，手性对称性是QCD的基本对称性之一。被称为手性微扰理论的有效场理论提供了一个系统和实用的框架，将量子光盘的对称性转化为强子的对称性，强子是实际构成原子核的粒子。本研究广泛运用了这种形式主义。为了描述那些目前超出手性微扰理论适用性的现象，使用了近似反映QCD对称性并可应用于复杂核的模型。具体地说，建议研究：核手性微扰理论应用于少核子系统的结果；少核子系统弱过程辐射修正的有效场理论估计及对现有介子-氘核俘获反应和中微子-氘核反应理论处理的系统改进核手性微扰理论在高能量动量转移非弹性反应中的应用中微子-氘核反应超过介子产生阈值。众所周知，有效场论方法在我们试图将原子核的性质与夸克和胶子的潜在动力学联系起来时非常有用。我们的研究不仅加深了对核强子物理的认识，而且对核天体物理学和寻找标准模型之外的物理具有重要意义。我们的研究与正在进行的和未来的中微子实验有着特别密切的联系，这些实验旨在寻找非标准物理的信号。预算允许我们聘请一名博士后和一名本科生加入我们的研究工作。

The focus of our research is to investigate nuclear-hadronic dynamics with a particular emphasis on its relation to quantum chromodynamics (QCD), the fundamental theory of quarks and gluons. Of particular interest is studying the role of chiral symmetry, which is one of the basic symmetries of QCD. The effective field theory named chiral perturbation theory offers a systematic and practical framework to translate the symmetries of QCD into those of hadrons, particles that actually constitute atomic nuclei. The proposed research makes extensive use of this formalism. To describe those phenomena that are at present beyond the applicability of chiral perturbation theory, models are used that approximately reflect the symmetries of QCD and that can be applied to complex nuclei. Specifically, it is proposed to study: eonsequences of nuclear chiral perturbation theory as applied to few-nucleon systems; effective-field-theoretical estimation of radiative corrections for weak processes in few-nucleon systems and systematic improvements of the existing theoretical treatments of the muon-deuteron capture reaction and neutrino-deuteron reactions; nuclear chiral perturbation theory applied to inelastic reactions involving rather high energy-momentum transfers; and neutrino-deuteron reactions beyond the pion-production threshold. The effective field theory approach is known to be highly useful in our attempt to relate the properties of atomic nuclei to the underlying dynamics of the quarks and gluons. Our investigations not only deepen the understanding of nuclear-hadron physics but also have important bearing upon nuclear astrophysics and search for physics beyond the standard model. Our study has particularly close connections with the on-going and future neutrino experiments that are meant to look for signals for non-standard physics. The budget allows us to hire a post-doctoral fellow and an undergraduate student to join our research effort.