On the Prospect of Tau Neutrino Astronomy in GeV Energies and Beyond G.-L. Lin National Chiao-Tung U. Taiwan Moriond 2005
Outline The current aspects of tau neutrino detections The reward for an effective discrimination of from other neutrino flavors— illustrated with the detection of galactic, atmospheric background considered in detail. Conclusion
The aspects of tau neutrino detections: E > 10 6 GeV Double bang events 2 showers separated by roughly 50 (E /PeV) m J. G. Learned and S. Pakvasa 1995 H. Athar, G. Parente and E. Zas 2000 E between GeV and PeV: make use of shower properties
Different shower distributions for NC and CC+ decays T. Stanev 1999 Upward atmospheric ’s ~100 GeV-- T. Stanev, 1999 Extragalactic ’s -- S. I. Dutta, M. H. Reno and I. Sarcevic, 2000 R=shower event rate/ muon event rate ( )~ ( ) in the above. It will be rewarding if one can do better in discriminating from other flavors—in the situation ( ) > ( ).
The prospect of detecting galactic : an illustration The Flux CR Interstellar medium n p =1 particle /cm 3 Intrinsic Flux: Due to oscillation: Athar, Jezabek and Yasuda, 2000 Bento, Keränen and Maalampi, 2000
in the unit cm -2 s -1 sr -1 GeV -1 Primary comic ray proton spectrum T. K. Gaisser and M. Honda, 2002
The flux of atmospheric background 2-flavor oscillation analysis Y. Ashie et al. [SK Collab.], 2004 We present the results with the best fit values H. Athar, hep-ph/ H. Athar, F.-F. Lee &GLL, hep-ph/ F.-F. Lee & GLL, hep-ph/
Neutrino energy H. Athar, F.-F. Lee and GLL, hep-ph/ Atmospheric flux before Oscillations The , K production cross Section taken from T. K. Gaisser, astro-ph/
The intrinsic tau neutrino flux can be calculated by perturbative QCD supplemented by models for D s decays. L. Pasquali, M. H. Reno and I. Sarcevic, 1999
Neutrino energy Atmospheric tau neutrino flux after oscillations Downward to Horizontal Directions, Oscillations Occur in Atmosphere F.-F. Lee and GLL, hep-ph/
Galactic =90 0 =66 0 =0 0 Neutrino energy F.-F. Lee and GLL, hep-ph/ Comparison of galactic and atmospheric ’s– downward to horizontal directions
Neutrino energy Comparison in the upward direction Galactic-plane observable through for E > TeV
Conclusion We have outlined the current strategy of identifying astrophysical . We made a detailed comparison between galactic and atmospheric neutrino flux. We showed that an effective discrimination of from other neutrino flavors is rewarding. The galactic-plane can be seen through in GeV to TeV energies.