NEUTRINO PRODUCTION FROM ACCRETING X-RAY PULSARS

There exist electrostatic acceleration regions (accelerator gaps) abov e the inner part of a Keplerian accretion disc of an x-ray pulsar whic h can accelerate positively charged particles (protons/ions) to extrem e relativistic energies (greater-than-or-equal-to 10(15) eV) towards t he accretion disc. The subsequent hadronic collisions between such ult rarelativistic protons (ions) and the disc material can produce numero us secondary mesons whose decay generates a luminous neutrino flux. Al though the neutrinos can directly escape from the collision regions wi thout any energy loss, the disc magnetic field can modify the neutrino spectrum because their unstable charged parent particles can lose ene rgy via synchrotron radiation. This can provide direct information on the structure of the accretion disc. In calculating the meson producti on rate, we have used an improved scaling violation model which has th e effect of enhancing the neutrino production rate. It appears that a large fraction of the accretion power of x-ray pulsars (approximately 10(37) erg s-1) could be carried away by the neutrino flux. It may be possible to detect these neutrino sources in future.