Mohamad-Ziad Charif - Antares

Figure 5.1: Dark Matter neutrino differential flux showing the difference betweenW + W − and τ + τ − annihilation channels.The softest neutrino flux is due to χ ¯χ → b¯b. The hard flux has been studiedwith two different channels. In most general models the hardest flux is producedby χ ¯χ → τ + τ − (Figure 5.1). However assuming the SUSY models it is commonto use fluxes produced by χ ¯χ → W + W − since in such models the branching ratioto τ + τ − is usually suppressed in comparison with W + W − . However since allν µ + ¯ν µ spectrum are normalized to 1 we would expect to see small differencesbetween τ and W annihilation channels when calculating the limits to neutrinofluxes.It is interesting to note that by examining Figure 5.1 , and 5.3 we notice thatthe ¯ν flux is higher than the ν. This is due to the fact that ν have higher interactionprobability with the Sun’s matter than ¯ν, resulting in larger absorption of ν than¯ν inside the Sun. Another remark is that we can see the effect of the neutrinooscillations on the fluxes. Nevertheless there is no reason to assume that theseoscillations can be detected with the current detector.Another note to be taken into consideration is that the absorption for neutrinoswith energies above 1 TeV in the Sun is considerable, we would expect to seethat the neutrino spectrum from the annihilation of WIMPS with masses higherthan 1 TeV has some sort of high energy cutoff as see in figure 5.2, so we wouldexpect that the limits of Soft and Hard spectra converge at very high WIMP masses(above 5 TeV).77