BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:Cosmic neutrino absorption spectroscopy
DTSTART;VALUE=DATE-TIME:20050621T100000Z
DTEND;VALUE=DATE-TIME:20050621T110000Z
DTSTAMP;VALUE=DATE-TIME:20261113T063102Z
UID:indico-event-1440@indico.ific.uv.es
DESCRIPTION:Annihilation of extremely energetic cosmic neutrinos on the re
 lic-neutrino background can give rise to absorption lines at energies corr
 esponding to formation of the electroweak gauge boson $Z^{0}$. The positio
 ns of the absorption dips are set by the masses of the relic neutrinos. Su
 itably intense sources of extremely energetic ($10^{21}$ -- $10^{25}$-eV) 
 cosmic neutrinos might therefore enable the determination of the absolute 
 neutrino masses and the flavor composition of the mass eigenstates. Severa
 l factors--other than neutrino mass and composition--distort the absorptio
 n lines\, however. We analyze the influence of the time-evolution of the r
 elic-neutrino density and the consequences of neutrino decay. We consider 
 the sensitivity of the lineshape to the age and character of extremely ene
 rgetic neutrino sources\, and to the thermal history of the Universe\, ref
 lected in the expansion rate. We take into account Fermi motion arising fr
 om the thermal distribution of the relic-neutrino gas. We also note the im
 plications of Dirac vs. Majorana relics\, and briefly consider unconventio
 nal neutrino histories.\n\nhttps://indico.ific.uv.es/event/1440/
LOCATION:Dpto. de Física Teórica (UVEG) Sala Seminarios
URL:https://indico.ific.uv.es/event/1440/
END:VEVENT
END:VCALENDAR