We observe a narrow enhancement near 2m(p) in the invariant mass spectrum of pp pairs from radiative J/psi-->gammapp decays. No similar structure is seen in J/psi-->pi(0)pp decays. The results are based on an analysis of a 58 x 10(6) event sample of J/psi decays accumulated with the BESII detector at the Beijing electron-positron collider. The enhancement can be fit with either an S- or P-wave Breit-Wigner resonance function. In the case of the S-wave fit, the peak mass is below 2m(p) at M=1859(+3)(-10) (stat)+5-25(syst) MeV/c(2) and the total width is Gamma<30 MeV/c(2) at the 90% confidence level. These mass and width values are not consistent with the properties of any known particle.

The Glashow resonance at E_\nu=6.3 PeV is a measure of the \bar\nu_e content of the astrophysical neutrino flux. The fractional \bar\nu_e content depends on the neutrino production model at the cosmic neutrino source, and the environment at the source. Thus, the strength of the Glashow resonance event rate is a potential window into astrophysical sources. We quantify the "Glashow resonometer" and comment on the significance that no Glashow events are observed in the IceCube three-year data.Comment: 11 pages, 2 tables, 1 figure. Version to appear as a Rapid Communication in PR

We report values of R = sigma(e(+)e(-)-->hadrons)/sigma(e(+)e(-)-->mu(+)mu(-)) for 85 center-of-mass energies between 2 and 5 GeV measured with the upgraded Beijing Spectrometer at the Beijing Electron-Positron Collider.

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Over cosmic distances, astrophysical neutrino oscillations average out to a classical flavor propagation matrix P. Thus, flavor ratios injected at the cosmic source W e , W µ , W τ evolve to flavor ratios at Earthly detectors w e , w µ , w τ according to w = P W . The unitary constraint reduces the Euclidean octant to a "flavor triangle". We prove a theorem that the area of the Earthly flavor triangle is proportional to Det(P). One more constraint would further reduce the dimensionality of the flavor triangle at Earth (two) to a line (one).We discuss four motivated such constraints. The first is the possibility of a vanishing determinant for P.We give a formula for a unique δ(θ ij 's) that yields the vanishing determinant. Next we consider the thinness of the Earthly flavor triangle. We relate this thinness to the small deviations of the two angles θ 32 and θ 13 from maximal mixing and zero, respectively. Then we consider the confusion resulting from the tau neutrino decay topologies, which are showers at low energy, "double-bang" showers in the PeV range, and a mixture of showers and tracks at even higher energies. We examine the simple low-energy regime, where there are just two topologies, w shower = w e + w τ and w track = w µ . We apply the statistical uncertainty to be expected from IceCube to this model. Finally, we consider ramifications of the expected lack of ν τ injection at cosmic sources. In particular, this constraint reduces the Earthly triangle to a boundary line of the triangle. Some tests of this "no ν τ injection" hypothesis are given.PACS numbers: 14.60. Pq, 95.55.Vj, 95.85.Ry