The Dilemma of Baryon Asymmetry in the Cosmos: State of the Art and Research Frontiers in December 2025

The observable universe presents a fundamental enigma that challenges the foundations of contemporary physics: the almost absolute predominance of matter over antimatter. This work reviews the state of the art regarding the Baryon Asymmetry of the Universe (BAU) as of late 2025 (ηB ≈ 6.1 × 10⁻¹⁰). We analyze recent tensions in primordial nucleosynthesis (EMPRESS collaboration) and neutrino asymmetry, as well as the consolidation of leptogenesis following the joint results from T2K and NOvA. Finally, we discuss the prospects for detecting new physics through searches for Electric Dipole Moments (ACME III, n2EDM) and intensity‑frontier experiments such as SHiP and MATHUSLA.