Research

Neutrinos are electrically neutral, weakly interacting elementary particles that come in three known flavors: electron, muon, and tau neutrinos. Neutrino oscillation demonstrates that neutrinos have non-zero masses and can change from one flavor to another as they propagate, providing clear evidence for physics beyond the Standard Model (SM). Understanding the origin and structure of neutrino masses remains an important open question, motivating various theoretical mass-generation models. Neutrinoless double beta decay is a particularly promising probe of the Majorana nature of neutrinos and could establish whether lepton number is violated. Beyond the SM, Non-Standard Interactions (NSIs) may modify neutrino production, propagation, and detection, offering new ways to explore fundamental interactions. Neutrinos may also possess electromagnetic properties, such as magnetic and electric dipole moments, charge radius, or other electromagnetic form factors, despite being electrically neutral. Together, these phenomena make neutrino physics a powerful avenue for probing new physics and the fundamental origin of particle masses and interactions.

The dark sector refers to hypothetical particles and interactions that have very weak or no direct interactions with ordinary matter, yet may play a crucial role in the evolution of the Universe. Dark matter, which constitutes a significant fraction of the Universe’s matter content, remains one of the most compelling mysteries in modern physics. Axions and axion-like particles (ALPs) are well-motivated light particles that can address fundamental questions such as the strong CP problem and may provide viable dark matter candidates; solar axions and ALPs produced in the Sun also offer promising opportunities to search for these particles through their interactions with matter and electromagnetic fields. Dark photons, associated with a new hidden U(1)U(1) gauge symmetry, provide another promising portal between the dark sector and the Standard Model through mechanisms such as kinetic mixing. Complementary searches using dark-matter direct-detection experiments, including XENONnT, PandaX-4T, and LZ, probe possible interactions of dark-sector particles with atomic nuclei or electrons. Together, searches across astrophysical observations, cosmological probes, and laboratory experiments offer exciting opportunities to uncover new physics beyond the Standard Model.

Primordial black holes (PBHs) are hypothetical black holes that could have formed in the early Universe from the collapse of sufficiently large density fluctuations. Their possible connection with dark matter makes PBHs an intriguing candidate for explaining part or all of the observed dark-matter abundance. PBHs can also have important implications for neutrino physics, as Hawking radiation from evaporating PBHs can produce neutrinos and other Standard Model particles, providing potential signatures in neutrino observatories. Experiments such as DUNE and JUNO can therefore probe and constrain PBH populations through searches for neutrino fluxes associated with PBH evaporation, providing complementary information on their abundance and mass distribution. In addition, the evaporation of PBHs can produce or constrain axions and axion-like particles (ALPs), whose subsequent interactions and decay signatures provide an additional probe of the dark sector and PBH evaporation. Dark-matter direct-detection experiments, including XENONnT, PandaX-4T, and LZ, can provide complementary constraints on PBH scenarios through possible particle signals associated with PBH evaporation and PBH-induced dark-matter interactions. Together, neutrino observatories, dark-matter experiments, and searches for axions/ALPs provide a powerful multi-messenger approach to testing PBH formation, evaporation, dark-matter connections, and physics beyond the Standard Model.