The ANtarctic Impulse Transient Antenna (ANITA) is the first long-duration balloon experiment designed to search and measure the flux of Greisen-Zapsepin-Kuzmin (GZK) neutrinos. We present new limits on neutrinos fluxes of astronomical origin from data collected with the successful launch of a 2-antenna prototype instrument, called ANITA-lite, that circled the Antarctic continent for 18.4 days in January 2004. We performed a search for Ultra-High-Energy (UHE) neutrinos with energies above 3 × 1018 eV. No excess events above the background expectation were observed and a neutrino flux following E-2 spectrum for all neutrino flavors, is limited to Ev-2F < 1.6 × 10-6 GeV cm-2 s-1 sr-1 for 1018.5 eV < Ev < 1023.5 eV at 90% confidence level. The launch of ANITA is scheduled for December 2006. Looking beyond ANITA, we describe a new idea, called ARIANNA (Antarctic Ross Iceshelf ANtenna Neutrino Array), to increase the sensitivity for GZK neutrinos by one order of magnitude better than ANITA.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Astronomy and Astrophysics
- Physics and Astronomy(all)