Can new heavy gauge bosons be observed in ultra-high energy cosmic neutrino events?

A wide range of models beyond the Standard Model predict charged and neutral resonances, generically called $W^{\prime }$ and $Z^{\prime }$ bosons, respectively. In this paper we study the impact of such resonances on the deep inelastic scattering of ultra-high energy neutrinos as well as on the resonant charged current ${\overline{\nu }}_e{e}^{-}$ scattering (Glashow resonance). We find that the effects of such resonances cannot be observed with the Pierre Auger Observatory or any foreseeable upgrade of it.

Figure 1

Total cross sections for CC ${\nu }_{\mu }N$ DIS (red line), NC ${\nu }_{\mu }N$ DIS (green line) and the Glashow resonance (solid black line) as a dependence on the incoming neutrino energy. The vertical line at $E_{\nu }=10^8\mathrm{GeV}$ indicates the lower energy threshold of the Auger Observatory. The red and green crosses show the CC DIS and NC DIS cross sections, respectively, in the SSM with $M_{W^{\prime }}=M_{Z^{\prime }}=4\mathrm{TeV}$. The resonant ${\overline{\nu }}_e{e}^{-}$ scattering including the contribution from the $W^{\prime }$ resonance is represented by the dashed, black line.

Figure 2

The $\mathrm{CC}+\mathrm{NC}$ ${\nu }_{\mu }N$ DIS cross sections in different G(221) models scaled to the cross section in the SM. The areas have been obtained by fixing either $M_{W^{\prime }}=4\mathrm{TeV}$ or $M_{Z^{\prime }}=4\mathrm{TeV}$ and scanning over the allowed parameter range of the model. For details we refer to Ref. [8]. For comparison we also show the ratio obtained with the SSM using $M_{W^{\prime }}=M_{Z^{\prime }}=4\mathrm{TeV}$.