Comparing and contrasting the νμ→ντ and νμ→νs solutions to the atmospheric neutrino problem with SuperKamiokande data -: art. no. 013006

The nu(mu) --> nu(tau) and nu(mu) --> nu(s) solutions to the atmospheric neutrino problem are compared with SuperKamiokande data. The differences between these solutions due to matter effects in the Earth are calculated for the ratio of mu-like to e-like events and for up-down flux asymmetries. These quantities are chosen because they are relatively insensitive to theoretical uncertainties in the overall neutrino flux normalization and detection cross sections and efficiencies. A chi(2) analysis using these quantities is performed yielding 3 sigma ranges which are approximately given by (0.725 - 1.0, 4 X 10(-4) - 2 X 10(-2) eV(2)) and (0.74 - 1.0, 1 X 10(-3) - 2 X 10(-2) eV(2)) for (sin(2)2 theta, Delta m(2)) for the nu(mu) --> nu(tau) and nu(mu) --> nu(s) solutions, respectively. Values of Delta m(2) smaller than about 2 X 10(-3) eV(2) are disfavored for the nu(mu) --> nu(s) solution, suggesting that future long baseline experiments should see a positive signal if this scenario is the correct one. [S0556-2821(98)00913-8].