A new probe of relic neutrino clustering using cosmogenic neutrinos

We propose a new probe of cosmic relic neutrinos (C$\nu$B) using their resonant scattering against cosmogenic neutrinos. Depending on the lightest neutrino mass and energy spectrum flux, Standard Model vector meson (such as hadronic $\rho$) resonance can be produced via $\nu\bar{\nu}$ annihilation. This leads to distinct absorption feature in flux at an solely determined by mass, apart from redshift. By numerical coincidence, position $\rho$-resonance overlaps with originally predicted peak Greisen-Zatsepin-Kuzmin (GZK) which offers enhanced effect higher redshifts. show that this GZK may observable future radio-based observatories, such IceCube-Gen2 radio, provided there exists large overdensity C$\nu$B distribution. therefore provides clustering redshifts, complementary laboratory probes KATRIN) zero