20.500.12556/RUL-175882 Beyond neutrino mass: observable $n$-$\bar{n}$ oscillations in UV complete seesaw models Next-generation experiments, such as the Deep Underground Neutrino Experiment and the European Spallation Source, are set to improve sensitivity to neutron-antineutron oscillation, a direct probe of ∆B = 2 baryon number violation, with particularly significant gains expected at the latter. The discovery of such a rare ∆B = 2 process would indicate physics beyond the Standard Model and could point to specific unified theories that allow observable ▫$n$▫-▫$\bar{n}$▫ transitions. We accordingly examine ▫$n$▫-▫$\bar{n}$▫ oscillations within a unified framework that accounts for charged fermion masses and generates viable neutrino masses via the seesaw mechanism. More specifically, we show that ▫$n$▫-▫$\bar{n}$▫ oscillations can arise from two specific topologies within two distinct SU(5) scenarios. One topology requires a presence of two color-sextet scalars in the Type II seesaw framework, whereas the other involves a scalar sextet and a color-octet fermion in the Type III seesaw framework. While the former topology can be realized in the SO(10)/Pati-Salam frameworks, the latter finds a natural embedding in SU(5), which constitutes one of the key novelties of our work. Remarkably enough, the same dynamics responsible for fermion masses also induces baryon number violation, thus linking ▫$n$▫-▫$\bar{n}$▫ oscillations to the flavor structure of the theory. We show that, given a TeV-scale mass for one of the colored states, upcoming searches for such ∆B = 2 processes can probe for a presence of the other colored states with masses up to 1011 GeV, well beyond the reach of colliders. This positions ▫$n$▫-▫$\bar{n}$▫ oscillations as a rare low-energy portal to grand unification and ultra-heavy new physics. physics of elementary particles fizika osnovnih delcev true false true Angleški jezik Slovenski jezik Članek v reviji 2025-11-12 13:15:18 2025-11-12 13:15:19 2025-12-16 03:43:46 0000-00-00 00:00:00 2025 0 0 26 str. art. no. 24 Vol. 2025 Nov. 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 539.1 1029-8479 10.1007/JHEP11(2025)024 256728579 JHEP11(2025)024_(1).pdf JHEP11(2025)024_(1).pdf 1 EE9634D4AC44E545566BAE74789E7DC4 cb0e6b849c6a33ed54cefcb72281d6c91fa3037661652fbca50c32987a5e70a4 6a6c70f8-bfc1-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=221812 https://link.springer.com/article/10.1007/JHEP11(2025)024 0 70023c6b-bfc1-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=221813 Fakulteta za matematiko in fiziko 0 0 0