We present measurements of nu(mu) disappearance in K2K, the KEK to Kamioka long-baseline neutrino oscillation experiment. One-hundred and twelve beam-originated neutrino events are observed in the fiducial volume of Super-Kamiokande with an expectation of 158.1(-8.6)(+9.2) events without oscillation. A distortion of the energy spectrum is also seen in 58 single-ring muonlike events with reconstructed energies. The probability that the observations are explained by the expectation for no neutrino oscillation is 0.0015% (4.3 sigma). In a two-flavor oscillation scenario, the allowed Delta m(2) region at sin(2)2 theta=1 is between 1.9 and 3.5x10(-3) eV(2) at the 90% C.L. with a best-fit value of 2.8x10(-3) eV(2)

Aims. Observations of shell-type supernova remnants (SNRs) in the GeV to multi-TeV γ-ray band, coupled with those at millimetre radio wavelengths, are motivated by the search for cosmic-ray accelerators in our Galaxy. The old-age mixed-morphology SNR W 28 (distance ∼2 kpc) is a prime target due to its interaction with molecular clouds along its northeastern boundary and other clouds situated nearby. Methods. We observed the W 28 field (for ∼40 h) at very high energy (VHE) γ-ray energies (E > 0.1 TeV) with the HESS. Cherenkov telescopes. A reanalysis of EGRET E > 100 MeV data was also undertaken. Results from the NANTEN 4 m telescope Galactic plane survey and other CO observations were used to study molecular clouds. Results. We have discovered VHE γ-ray emission (HESS J1801−233) coincident with the northeastern boundary of W 28 and a complex of sources (HESS J1800−240A, B and C) ∼0.5 • south of W 28 in the Galactic disc. The EGRET source (GRO J1801−2320) is centred on HESS J1801−233 but may also be related to HESS J1800−240 given the large EGRET point spread function. The VHE differential photon spectra are well fit by pure power laws with indices Γ ∼ 2.3 to 2.7. The spectral indices of HESS J1800−240A, B, and C are consistent within statistical errors. All VHE sources are ∼10 in intrinsic radius except for HESS J1800−240C, which appears pointlike. The NANTEN 12 CO(J = 1−0) data reveal molecular clouds positionally associating with the VHE emission, spanning a ∼15 km s −1 range in local standard of rest velocity. Conclusions. The VHE/molecular cloud association could indicate a hadronic origin for HESS J1801−233 and HESS J1800−240, and several cloud components in projection may contribute to the VHE emission. The clouds have components covering a broad velocity range encompassing the distance estimates for W 28 (∼2 kpc) and extending up to ∼4 kpc. Assuming hadronic origin and distances of 2 and 4 kpc for cloud components, the required cosmic-ray density enhancement factors (with respect to the solar value) are in the range ∼10 to ∼30. If situated at 2 kpc distance, such cosmic-ray densities may be supplied by SNRs like W 28. Additionally and/or alternatively, particle acceleration may come from several catalogued SNRs and SNR candidates, the energetic ultra compact HII region W 28A2, and the HII regions M 8 and M 20, along with their associated open clusters. Further sub-mm observations would be recommended to probe in detail the dynamics of the molecular clouds at velocites >10 km s −1 and their possible connection to W 28. Key words. gamma rays: observationsEnergy spectra are only available in electronic form at

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).

Supernova remnants ($=$ SNR) are suggested to be sites of cosmic-ray acceleration. In particular, it has been an issue of keen interest whether cosmic ray protons are being accelerated in a SNR which emits TeV $\gamma$-rays. A crucial observational test for this is to find dense molecular gas towards the SNR, because such molecular gas can best verify the existence of cosmic-ray protons via pion decay to $\gamma$-rays. Here, we show that new high-resolution mm-wave observations of interstellar CO molecule have revealed molecular gas at 1 kpc distance interacting with the TeV $\gamma$-ray SNR G 347.3$-$0.5, and that a molecular cloud of $\sim 200$ solar masses is clearly associated with the TeV $\gamma$-ray peak, providing strong evidence for proton acceleration. We have estimated the total energy of accelerated protons to be $\sim 1048 \,\mathrm{erg}$, which corresponds to an acceleration efficiency of $\sim 0.001$, posing an observational constraint on the proton acceleration.