Project GRAND is a 100m × 100m air shower array of proportional wire chambers (PWCs). There are 64 stations each with eight 1.29 m 2 PWC planes arranged in four orthogonal pairs placed vertically above one another to geometrically measure the angles of charged secondaries. A steel plate above the bottom pair of PWCs differentiates muons (which pass undeflected through the steel) from non-penetrating particles. FLUKA Monte Carlo studies show that a TeV gamma ray striking the atmosphere at normal incidence produces 0.23 muons which reach ground level where their angles and identities are measured. Thus, paradoxically, secondary muons are used as a signature for gamma ray primaries. The data are examined for possible angular and time coincidences with eight gamma ray bursts (GRBs) detected by BATSE. Seven of the GRBs were selected because of their good acceptance by GRAND and high BATSE fluence. The eighth GRB was added due to its possible coincident detection by Milagrito. For each of the eight candidate GRBs, the number of excess counts during the BATSE T90 time interval and within ±5• of BATSE's direction was obtained. The highest statistical significance reported in this paper (2.7σ) is for the event that was predicted to be the most likely to be observed (GRB 971110).

Based on rotationally resolved sub-Doppler spectroscopy and optical–optical double resonance (OODR) experiments on cold Na3 molecules in a collimated supersonic argon beam seeded with sodium, 51 rotational transitions selectively excited by OODR in the complex electronic A 2A2←X 2B2 system of Na3 could be assigned unambigiously. Accurate values of the rotational constants and the molecular geometrical parameters have been derived from these measurements.

The extent to which atmospheric neutrino interactions can mimic nucleon decay into modes with a strange particle in the final state is evaluated using $;-deuterium interactions recorded by the 12-Foot Bubble Chamber at the ANL Zero Gradient Synchrotron. Event distributions representative of atmospheric neutrinos with 1 < E , < 5 GeV are studied. Such neutrino interactions in massive underground detectors will yield KO and K' mesons with respective rates of 1 . 5 i 0 . 8 and 4.2i-2.3 per kiloton year. However, the neutrino-induced events have final-state invariant mass and net momentum which are distinctly different from the values that characterize nucleon decay. Consequently, at lifetime levels corresponding to ten kiloton years of detector exposure, experimental searches capable of reconstructing these variables will not encounter substantial neutrino background for nucleon-decay modes leading to K mesons in the final state.

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