Extensive Air Shower Radio Detection: Recent Results and Outlook

A prototype system for detecting radio pulses associated with extensive cosmic ray air showers is described. Sensitivity is compared with that in previous experiments, and lessons are noted for future studies.Comment: 17 pages, LaTeX, 7 figures, invited talk presented by J. Rosner at RADHEP-2000 Conference, UCLA, Nov. 16-18, 2000, Proceedings published by AIP. Some figures and text changed; one reference update

A prototype system for detecting the radio-frequency pulse associated with cosmic ray air showers

The development of a system to detect the radio-frequency (RF) pulse associated with extensive air showers of cosmic rays is described. This work was performed at the CASA/MIA array in Utah, with the intention of designing equipment that can be used in conjunction with the Auger Giant Array. A small subset of data (less than 40 out of a total of 600 hours of running time), taken under low-noise conditions, permitted upper limits to be placed on the rate for pulses accompanying showers of energies around $10^{17}$ eV.Comment: 53 pages, LaTeX, 19 figures, published in Nuclear Instruments and Methods. Revised version; some references update

The B -> pi K Puzzle and New Physics

The present B -> pi K data is studied in the context of the standard model (SM) and with new physics (NP). We confirm that the SM has difficulties explaining the B -> pi K measurements. By adopting an effective-lagrangian parametrization of NP effects, we are able to rule out several classes of NP. Our model-independent analysis shows that the B -> pi K data can be accommodated by NP in the electroweak penguin sector.Comment: 4 pages (revtex

Synchrotron Radiation at Radio Frequencies from Cosmic Ray Air Showers

We review some of the properties of extensive cosmic ray air showers and describe a simple model of the radio-frequency radiation generated by shower electrons and positrons as they bend in the Earth's magnetic field. We perform simulations by calculating the trajectory and radiation of a few thousand charged shower particles. The results are then transformed to predict the strength and polarization of the electromagnetic radiation emitted by the whole shower.Comment: 18 pages, LaTeX, 7 figures, accepted for publication in Astropart. Phys. Added pancake profiles (fig. 1

Phenomenology of charmless hadronic B decays

The decays of $B$ mesons to a pair of charmless pseudoscalar mesons ($PP$ decays) or to a vector and pseudoscalar meson ($VP$ decays) have been analyzed within the framework of flavor SU(3) symmetry and the Kobayashi-Maskawa mechanism of CP violation. Separate $PP$ and $VP$ fits proved to be successful in describing the experimental data (branching ratios, CP asymmetries and time-dependent parameters). Decay magnitudes and relative weak and strong phases have been extracted from the fits. Values of the weak phase $\gamma$ were found to be consistent with the current indirect bounds from other analyses of CKM parameters.Comment: Talk presented at the Sixth International Conference on Hyperons, Charm and Beauty Hadrons, IIT, Chicago, June 27 - July 3, 200

Measuring the Relative Strong Phase in D0→K∗+K−D^0 \to K^{*+} K^- and D0→K∗−K+D^0 \to K^{*-} K^+ Decays

In a recently suggested method for measuring the weak phase $\gamma$ in $B^\pm \to K^\pm (KK^*)_D$ decays, the relative strong phase $\delta_D$ in $D^0 \to K^{*+} K^-$ and $D^0 \to K^{*-} K^+$ decays (equivalently, in $D^0 \to K^{*+} K^-$ and \od \to K^{*+} K^-) plays a role. It is shown how a study of the Dalitz plot in $D^0 \to K^+ K^- \pi^0$ can yield information on this phase, and the size of the data sample which would give a useful measurement is estimated.Comment: 13 pages, latex, 5 figures, submitted to Phys. Rev. D. Appendix and some text on additional resonant contributions adde

Determination of gamma from charmless B^+/- -> M^0 M^+/- decays using U-spin

U-spin multiplet approach is applied to the full set of charmless hadronic B+/- --> M0 M+/- decays for the purpose of precise extraction of the unitarity angle gamma. Each of the four data sets, P0 P+/-, P0 V+/-, V0 P+/- and V0 V+/-, with P = pseudoscalar and V = vector, can be used to yield a precise value of gamma. The crucial advantage of this method over the common SU(3) symmetry based quark-diagrammatic approach is that no assumptions regarding relative sizes of topological decay amplitudes need to be made. As a result, this method avoids an uncontrollable theoretical uncertainty that is related to the neglect of some topological diagrams (e.g., exchange and annihilation graphs) in the SU(3) approach. Application of the U-spin approach to the current data yields: gamma=54^{+12}_{-11} degrees. We find that improved measurements of phi pi+/- and K*0bar K+/- branching ratios would lead to appreciably better extraction of gamma. In this method, which is completely data driven, in a few years we should be able to obtain a model independent determination of gamma with an accuracy of O(few degrees).Comment: 5 pages; minor changes, further clarification on key differences with the SU(3) approach; added reference

Charmless B→PPB \to PP decays using flavor SU(3) symmetry

The decays of $B$ mesons to a pair of charmless pseudoscalar ($P$) mesons are analyzed within a framework of flavor SU(3). Symmetry breaking is taken into account in tree ($T$) amplitudes through ratios of decay constants; exact SU(3) is assumed elsewhere. Acceptable fits to $B \to \pi \pi$ and $B \to K \pi$ branching ratios and CP asymmetries are obtained with tree, color-suppressed ($C$), penguin ($P$), and electroweak penguin ($P_{EW}$) amplitudes. Crucial additional terms for describing processes involving $\eta$ and $\eta'$ include a large flavor-singlet penguin amplitude ($S$) as proposed earlier and a penguin amplitude $P_{tu}$ associated with intermediate $t$ and $u$ quarks. For the $B^+ \to \pi^+ \eta'$ mode a term $S_{tu}$ associated with intermediate $t$ and $u$ quarks also may be needed. Values of the weak phase $\gamma$ are obtained consistent with an earlier analysis of $B \to VP$ decays, where $V$ denotes a vector meson, and with other analyses of CKM parameters.Comment: 26 pages, 1 figure. To be submitted to Phys. Rev. D. Reference update