Observation of a Narrow Resonance of Mass 2.46 GeV/c^2 in the D_s^*+\pi^0 Final State, and Confirmation of the D_sJ^*(2317)

Using 13.5 fb^{-1} of e^+e^- annihilation data collected with the CLEO-II detector, we have observed a new narrow resonance in the D_s^*\pi^0 final state, with a mass near 2.46 GeV/c^2. The search for such a state was motivated by the recent discovery by the BaBar Collaboration of a narrow state at 2.32 GeV/c^2, the D_{sJ}^*(2317)^+, that decays to D_s\pi^0. Reconstructing the D_s\pi^0 and D_s^*\pi^0 final states in CLEO data, we observe a peak in each of the corresponding reconstructed mass difference distributions, \Delta M_{D_s\pi^0} = M(D_s\pi^0) - M(D_s) and \Delta M_{D_s^*\pi^0} = M(D_s^*\pi^0) - M(D_s^*), both of them at values around 350 MeV/c^2. These peaks constitute statistically significant evidence for two distinct states, at 2.32 and 2.46 GeV/c^2, taking into account the background source that each state comprises for the other in light of the nearly identical values of \Delta M observed for the two peaks. We have measured the mean mass differences \Delta M_{D_s\pi^0} = 350.4 \pm 1.2[stat.] \pm 1.0 [syst.] MeV/c^2 for the $D_{sJ}^*(2317)^+$ state, and \Delta M_{D_s^*\pi^0} = 351.6 \pm 1.7[stat.] \pm 1.0 [syst.] MeV/c^2 for the new state at 2.46 GeV/c^2. We have also searched, but find no evidence, for decays of D_{sJ}^*(2317) into the alternate final states D_s^*\gamma, D_s\gamma, and D_s\pi^+\pi^-. The observations of the two states at 2.32 and 2.46 GeV/c^2, in the D_s\pi^0 and D_s^*\pi^0 decay channels respectively, are consistent with their possible interpretations as c s-bar mesons with orbital angular momentum L=1, and spin-parity J^P = 0^+ and 1^+.Comment: 12 pages postscript, Updated Author List, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to 8th CIPANP May 200

Measurement of sigma_Total in e+e- Annihilations Below 10.56 GeV

Using the CLEO III detector, we measure absolute cross sections for e+e- -> hadrons at seven center-of-mass energies between 6.964 and 10.538 GeV. R, the ratio of hadronic and muon pair production cross sections, is measured at these energies with a r.m.s. error <2% allowing determinations of the strong coupling alpha_s. Using the expected evolution of alpha_s with energy we find alpha_s(M_Z^2)=0.126 +/- 0.005 ^{+0.015}_{-0.011}, and Lambda=0.31^{+0.09+0.29}_{-0.08-0.21}.Comment: Comments: Presented at "The 2007 Europhysics Conference on High Energy Physics," Manchester, England, 19-25 July 2007, to appear in the proceedings. Three pages, 1 figur

Search for neutrinos from decaying dark matter with IceCube

This work is licensed under a Creative Commons Attribution 4.0 International License.With the observation of high-energy astrophysical neutrinos by the IceCube Neutrino Observatory, interest has risen in models of PeV-mass decaying dark matter particles to explain the observed flux. We present two dedicated experimental analyses to test this hypothesis. One analysis uses 6 years of IceCube data focusing on muon neutrino ‘track’ events from the Northern Hemisphere, while the second analysis uses 2 years of ‘cascade’ events from the full sky. Known background components and the hypothetical flux from unstable dark matter are fitted to the experimental data. Since no significant excess is observed in either analysis, lower limits on the lifetime of dark matter particles are derived: we obtain the strongest constraint to date, excluding lifetimes shorter than 10^28 s at 90% CL for dark matter masses above 10 TeV

Relativistic Magnetic Monopole Flux Constraints from RICE

We report an upper limit on the flux of relativistic monopoles based on the non-observation of in-ice showers by the Radio Ice Cherenkov Experiment (RICE) at the South Pole. We obtain a 95% C.L. limit of order 10^{-18}/(cm^2-s-sr) for intermediate mass monopoles of 10^7<gamma<10^{12} at the anticipated energy E=10^{16} GeV. This bound is over an order of magnitude stronger than all previously published experimental limits for this range of boost parameters gamma, and exceeds two orders of magnitude improvement over most of the range. We review the physics of radio detection, describe a Monte Carlo simulation including continuous and stochastic energy losses, and compare to previous experimental limits.Comment: 16 pages, 6 figures. Accepted for publication in Phys. Rev. D. Minor revisions, including expanded discussion of monopole energy uncertaint

Simulation of a Hybrid Optical/Radio/Acoustic Extension to IceCube for EeV Neutrino Detection

Astrophysical neutrinos at $\sim$EeV energies promise to be an interesting source for astrophysics and particle physics. Detecting the predicted cosmogenic (``GZK'') neutrinos at 10$^{16}$ - 10$^{20}$ eV would test models of cosmic ray production at these energies and probe particle physics at $\sim$100 TeV center-of-mass energy. While IceCube could detect $\sim$1 GZK event per year, it is necessary to detect 10 or more events per year in order to study temporal, angular, and spectral distributions. The IceCube observatory may be able to achieve such event rates with an extension including optical, radio, and acoustic receivers. We present results from simulating such a hybrid detector.Comment: 4 pages, 2 figures; to appear in the Proceedings of the 29th ICRC, Pune, Indi