RESUMEN
We performed an improved search for nu(mu) --> nu(e) oscillation with the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment, using the full data sample of 9.2 x 10(19) protons on target. No evidence for a nu(e) appearance signal was found, and we set bounds on the nu(mu) --> nu(e) oscillation parameters. At Deltam(2)=2.8 x 10(-3) eV(2), the best-fit value of the K2Knu(mu) disappearance analysis, we set an upper limit of sin(2)2theta(mue) < 0.13 at a 90% confidence level.
RESUMEN
We report the result from a search for charged-current coherent pion production induced by muon neutrinos with a mean energy of 1.3 GeV. The data are collected with a fully active scintillator detector in the K2K long-baseline neutrino oscillation experiment. No evidence for coherent pion production is observed, and an upper limit of is set on the cross section ratio of coherent pion production to the total charged-current interaction at 90% confidence level. This is the first experimental limit for coherent charged pion production in the energy region of a few GeV.
RESUMEN
We present results for nu(mu) oscillation in the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment. K2K uses an accelerator-produced nu(mu) beam with a mean energy of 1.3 GeV directed at the Super-Kamiokande detector. We observed the energy-dependent disappearance of nu(mu), which we presume have oscillated to nu(tau). The probability that we would observe these results if there is no neutrino oscillation is 0.0050% (4.0 sigma).