This book includes peer-reviewed articles from the XXVI DAE-BRNS High Energy Physics (HEP) Symposium 2024, held at Varanasi in India. It highlights the latest research trends and advancements in high energy physics, astroparticle physics, and cosmology from both experimental and theoretical perspectives. The book covers progress in a wide range of topics such as Standard Model Physics, Beyond Standard Model Physics, Neutrino Physics, Dark Matter searches, Particle Astrophysics, and Cosmology, Relativistic Heavy-Ion Physics, as well as Quantum Chromodynamics (QCD) for the last two years. A significant focus is on recent progress in lattice gauge theory, offering more precise predictions of chiral and deconfinement phase transitions. This volume also explores advancements in detector development and future experimental facilities, alongside formal theoretical research and societal applications, particularly in fields like Medical Physics and Imaging.