AZƏRBAYCAN RESPUBLİKASININ ELM VƏ TƏHSİL NAZİRLİYİ Bakı Dövlət Universiteti

The Department of Theoretical Physics was established from the High Energy Laboratory, which was active in Baku from 1990 to 2005. Founded in 1990 with the approval of the USSR Committee for Atomic Energy, the laboratory focused on two primary research areas: theoretical studies of strong interactions among elementary particles within quantum chromodynamics and the development and application of semiconductor vertex detectors for detecting high-energy particles. The detectors designed at the laboratory underwent testing at the Institute of High Energy in Protvino, Russia, under the "Poleks" program. Starting in 1993, the laboratory expanded its theoretical research to include topics such as the Drell- Yan process, the calculation of meson electromagnetic form factors through various methods, the exploration of high twist effects in hadronic collisions, the analysis of particle motion in external chromospheres according to Yang-Mills theory, and the calculation of invariant groups in mathematical physics. In 2005, the laboratory was integrated into the Department of Theoretical Physics at the Institute of Physical Problems, operating as an independent group from 2008 to 2019. In 2019, the Department of Theoretical Physics was officially established based on the High Energy group. The scientific findings produced by the department's Research Associates are published in reputable international journals. Furthermore, these results have been shared at various scientific conferences in the USA, France, Germany, Italy, Turkey, Iran, and Pakistan. Department personnel actively engage in grant projects of diverse levels and collaborate on research initiatives with numerous scientific centers, institutes, and universities globally. Subject: Investigation of the characteristics of hadrons and their associated processes. Objective: Key objectives in high energy physics include examining the internal structure of mesons and baryons, conducting comparative analyses of their masses, coupling constants, and decay channels based on experimental data, and advancing various mathematical techniques. Alongside conventional hadrons composed of two and three quarks, significant scientific pursuits involve exploring the internal structures of multiquark systems—such as tetraquarks, pentaquarks, and hexaquarks. According to the standard model, mesons are formed from quark-antiquark pairs, while baryons consist of three quarks. However, quantum chromodynamics does not restrict the existence of multiquark hadrons. Since the discovery of the exotic resonance X(3872) in 2003, research in this field has accelerated, resulting in the identification of new particles and the formulation of theoretical methods. In addition to the excitation theory of quantum chromodynamics (QCD), various other methodologies are extensively employed in calculations involving hadronic processes, including the light-cone sum rules of QCD, group-theoretical approaches, mathematical optimization techniques, and non-perturbative methods grounded in integral equations of quantum field theory. The dynamics of physical systems under various types of close interactions are also investigated within hadronic physics, providing insights into bound states, resonant states, and scattering phenomena.