// BNL has somewhat tricky signal definition for the selection:
// P_visible = visible 4-momentum, so the three tracks total momentum
// P_visible > 150 MeV/c2
// Theta_Pvis_nu (angle between visible momentum and neutrino direction) < 50 degrees
// At least one negative track leaves chamber without interacting or stops consistent with muon
// THESE ARE NOT IMPLEMENTED BUT SHOULD BE KNOWN BY ANYONE WHO FITS THIS DATA! (see Kitagaki et al. 2556)
//
// The only actual restriction seems to be the final state particles. There's no mention of E_nu restrictions either (events span to 10GeV in fig 2, Kitagaki)
// There's a mention of uncertainity in the neutrino flux for Enu > 6.0 GeV