Volumetric budget and grain-size fractionation of a geological sediment routing system: Eocene Escanilla Formation, south-central Pyrenees

The supply of sediment and its characteristic grain-size mix are key controls on depositional facies and stratigraphic architectures in sedimentary basins. Consequently, constraints on sediment caliber, budgets, and fluxes are a prerequisite for effective stratigraphic prediction. Here, we investigate a mid- to late Eocene (41.6–33.9 Ma) sediment routing system in the Spanish Pyrenees. We derive a full volumetric sediment budget, weighted for grain-size fractions, partitioned between terrestrial and marine depositional sectors, and we quantify sediment fluxes between depocenters. The paleo–sediment routing system was controlled by syndepositional thrust tectonics and consisted of two major feeder systems eroding the high Pyrenees that supplied a river system draining parallel to the regional tectonic strike and that ultimately exported sediment to coastal, shallow- marine and deep-marine depo centers. We show significant changes in both the volume and grain-size distribution of sediment eroded from the Pyrenean mountain belt during three different time intervals in the mid- to late Eocene, which controlled the characteristics of stratigraphy preserved in a series of wedge-top basins The time-averaged sediment discharge from source areas increased from ~250 km3/m.y. to 700 km3/m.y. over the 7.7 m.y. interval investigated. This temporal increase in sediment supply caused major westward progradation of facies belts and led to substantial sediment bypass through the terrestrial routing system to the (initially) marine Jaca Basin. The grain-size mix, measured as size fractions of gravel, sand, and fi ner than sand, also changed over the three time intervals intervals. Integration of volumetric and grain-size information from source to sink provides an estimate of the long-term grain-size distribution of the sediment supply, comprising 9% gravel, 24% sand, and 67% finer than sand. The techniques and concepts used in the Escanilla study can profitably be applied to paleo–sediment routing systems in other tectonic and climatic settings and to catchments with a range of bedrock lithology and vegetation. This will promote a better generic understanding of the dynamics of source-to sink systems and provide a powerful tool for forward stratigraphic modeling. The sediment routing system approach has the potential to contribute strongly to new models of sequence stratigraphy

Non-commutative oscillator with Kepler-type dynamical symmetry

A 3-dimensional non-commutative oscillator with no mass term but with a certain momentum-dependent potential admits a conserved Runge-Lenz vector, derived from the dual description in momentum space. The latter corresponds to a Dirac monopole with a fine-tuned inverse-square plus Newtonian potential, introduced by McIntosh, Cisneros, and by Zwanziger some time ago. The trajectories are (arcs of) ellipses, which, in the commutative limit, reduce to the circular hodographs of the Kepler problem. The dynamical symmetry allows for an algebraic determination of the bound-state spectrum and actually extends to the conformal algebra o(4,2).Comment: 10 pages, 3 figures. Published versio

Evaluation of the potential for virus dispersal during hand drying: a comparison of three methods

Aims To use a MS2 bacteriophage model to compare three hand-drying methods, paper towels (PT), a warm air dryer (WAD) and a jet air dryer (JAD), for their potential to disperse viruses and contaminate the immediate environment during use. Methods and Results Participants washed their gloved hands with a suspension of MS2 bacteriophage and hands were dried with one of the three hand-drying devices. The quantity of MS2 present in the areas around each device was determined using a plaque assay. Samples were collected from plates containing the indicator strain, placed at varying heights and distances and also from the air. Over a height range of 0.15-1.65 m, the JAD dispersed an average of >60 and >1300-fold more plaque-forming units (pfu) compared to the WAD and PT (P 20 and >190-fold more pfu in total compared to WAD and PT at all distances tested up to 3 m (P 50 and >100-fold more pfu compared to the WAD and PT (P <0.001), respectively. Conclusions Use of the JAD lead to significantly greater and further dispersal of MS2 bacteriophage from artificially contaminated hands when compared to the WAD and PT. Significance and Impact of Study The choice of hand drying device should be considered carefully in areas where infection prevention concerns are paramount, such as healthcare settings and the food industry

Search for CP Violation in Charged D Meson Decays

We report results of a search for CP violation in the singly Cabibbo-suppressed decays D+ -> K- K+ pi+, phi pi+, K*(892)0 K+, and pi- pi+ pi+ based on data from the charm hadroproduction experiment E791 at Fermilab. We search for a difference in the D+ and D- decay rates for each of the final states. No evidence for a difference is seen. The decay rate asymmetry parameters A(CP), defined as the difference in the D+ and D- decay rates divided by the sum of the decay rates, are measured to be: A(CP)(K K pi) = -0.014 +/- 0.029, A(CP)(phi pi) = -0.028 +/- 0.036, A(CP)(K*(892) K) = -0.010 +/- 0.050, and A(CP)(pi pi pi) = -0.017 +/- 0.042.Comment: 13 pages, 5 figures, 1 table; Elsevier LaTe

Branching Fractions for D0 -> K+K- and D0 -> pi+pi-, and a Search for CP Violation in D0 Decays

Using the large hadroproduced charm sample collected in experiment E791 at Fermilab, we have measured ratios of branching fractions for the two-body singly-Cabibbo-suppressed charged decays of the D0: (D0 -> KK)/(D0 -> Kpi) = 0.109 +- 0.003 +- 0.003, (D0 -> pipi)/(D0 -> Kpi) = 0.040 +- 0.002 +- 0.003, and (D0 -> KK)/(D0 -> pipi) = 2.75 +- 0.15 +- 0.16. We have looked for differences in the decay rates of D0 and D0bar to the CP eigenstates K+K- and pi+pi-, and have measured the CP asymmetry parameters A_CP(K+K-) = -0.010 +- 0.049 +- 0.012 and A_CP(pi+pi-) = -0.049 +- 0.078 +- 0.030, both consistent with zero.Comment: 10 Postscript pages, including 2 figures. Submitted to Phys. Lett.

Search for Rare and Forbidden Dilepton Decays of the D+, Ds, and D0 Charmed Mesons

We report the results of a search for flavor-changing neutral current, lepton-flavor violating, and lepton-number violating decays of D+, Ds, and D0 mesons (and their antiparticles) into modes containing muons and electrons. Using data from Fermilab charm hadroproduction experiment E791, we examine the pi,l,l and K,l,l decay modes of D+ and Ds and the l+l- decay modes of D0. No evidence for any of these decays is found. Therefore, we present branching-fraction upper limits at 90% confidence level for the 24 decay modes examined. Eight of these modes have no previously reported limits, and fourteen are reported with significant improvements over previously published results.Comment: 12 pages, 3 figures, LaTeX, elsart.cls, epsf.sty, amsmath.sty Submitted to Physics Letters

Asymmetries between the production of D+ and D- mesons from 500 GeV/c pi- nucleon interactions as a function of xF and pt**2

We present asymmetries between the production of D+ and D- mesons in Fermilab experiment E791 as a function of xF and pt**2. The data used here consist of 74,000 fully-reconstructed charmed mesons produced by a 500 GeV/c pi- beam on C and Pt foils. The measurements are compared to results of models which predict differences between the production of heavy-quark mesons that have a light quark in common with the beam (leading particles) and those that do not (non-leading particles). While the default models do not agree with our data, we can reach agreement with one of them, PYTHIA, by making a limited number of changes to parameters used

The First VERITAS Telescope

The first atmospheric Cherenkov telescope of VERITAS (the Very Energetic Radiation Imaging Telescope Array System) has been in operation since February 2005. We present here a technical description of the instrument and a summary of its performance. The calibration methods are described, along with the results of Monte Carlo simulations of the telescope and comparisons between real and simulated data. The analysis of TeV $\gamma$-ray observations of the Crab Nebula, including the reconstructed energy spectrum, is shown to give results consistent with earlier measurements. The telescope is operating as expected and has met or exceeded all design specifications.Comment: Accepted by Astroparticle Physic