Antineutrino-neutrino and antineutrino-electron resonant annihilation through rho and other vector mesons

The ν̄e → π−π0 and νe+ → π+π0 reactions have a resonant structure whenever the energy of the s–channel equals the mass of a JP = 1 vector meson. The resonant cross sections are of the order 10−38 cm2 and correspond to cosmic ray antineutrino energies in the range 0.20 to 2.00 TeV. A similar structure occurs in the annihilation of cosmic ray antineutrinos with a relic (background) neutrino. For mν ≤ 10−3 eV the resonant energy is above GZK limit and their decay products include multiple γ–rays. Possible detection schemes are discussed, especially those which rely on Cherenkov radiation. 1 Neutrino–initiated reactions in water. The first-generation neutrino telescopes (Lake Baikal, AMANDA) are in operation and the next-generation telescopes are under construction. The main purpose of these experiments is to detect cosmic neutrinos (and/or antineutrinos) with energy in TeV-EeV region, which are believed to be coming to the earth from gamma-ray bursts and active galactic nuclei. For their detection the following neutrino interactions in water are usually considered. 1. Charged–current induced neutrino-nucleon reactions [1] νl N → l X σ(νN) ≈ 0.67 · 10 ( Eν 1 GeV ) cm , (1) and antineutrino interactions ν̄l N → l X σ(ν̄N) ≈ 0.34 · 10 ( Eν 1 GeV )