Probing the central engine of long gamma-ray bursts and hypernovae with
  gravitational waves and neutrinos
  There are the two common candidates as the viable energy source for the
central engine of long gamma-ray bursts (GRBs) and hypernovae (HNe), neutrino
annihilation and magnetic fields. We investigate gravitational wave (GW)
emission accompanied by these two mechanisms. Especially, we focus on GW
signals produced by neutrinos from a hyper-accreting disk around a massive
black hole. We show that neutrino-induced GWs are detectable for $\sim$1 Mpc
events by LISA and $\sim$ 100 Mpc by DECIGO/BBO, if the central engine is
powered by neutrinos. The GW signals depend on the viewing angle and they are
anti-correlated with neutrino ones. But, simultaneous neutrino detections are
also expected, and helpful for diagnosing the explosion mechanism when later
electromagnetic observations enable us to identify the source. GW and neutrino
observations are potentially useful for probing choked jets that do not produce
prompt emission, as well as successful jets. Even in non-detection cases,
observations of GWs and neutrinos could lead to profitable implications for the
central engine of GRBs and HNe.
