- First Name:Taka
- Last Name:Kajino
- Working Group Presenter
- Title:UHE-Neutrinos and nucleosyntehsis in collapsar as evidence for GRB central engines
- Presentation Type:Talk
- Presentation Work Group:Neutrino Astronomy
- Abstract:Gamma-ray bursts (GRBs) are presumed to be powered by still unknown central engines for the time-scales in the range 1 ms $¥sim$ a few seconds. We propose that the GRB central engines would be a viable site for strong meson synchrotron emission if they were the compact astrophysical objects such as neutron stars or rotating black holes with extremely strong magnetic fields $H ¥sim10^{15}$ G and if protons or heavy nuclei were accelerated to ultra-relativistic energies of order $¥sim 10^{12}-10^{22}$ eV. We show that the charged scalar mesons like $¥pi^{¥pm}$, vector mesons like $¥rho$, and even heavier mesons like $D_S, J/¥Psi$ and $¥Upsilon$, could be emitted with high intensity a thousand times larger than photons through strong couplings to ultra-relativistic nucleons. These meson synchrotron emission processes eventually produce a burst of three flavors of ultra high-energy cosmic neutrinos with $10^{12}$ eV $¥leq E_{¥nu}$. We estimate the spectra of $¥mu$-- and $¥tau$--neutrinos, which might be produced by the decay of massive mesons like $¥Upsilon$. These neutrinos could be detected during the early time duration of short GRBs.