Radio-frequency probes of Antarctic ice at South Pole

Using hardware developed for the ARA (Askaryan Radio Array) particle astrophysics experiment, we herein report on the amplitude and temporal characteristics of polarized surface radar echo data collected in South Polar ice using radio sounding equipment with 0.5-ns echo-time sampling. We observe strong echoes at 6, 9.6, 13.9, 17, and 19 μs following vertical pulse emission from the surface, corresponding to reflectors in the upper half of the ice sheet. The synchronicity of those echoes for all broadcast azimuthal polarizations affirms the lack of observable birefringence over the upper half of the ice sheet. Of the five strongest echoes, three exhibit an evident amplitude correlation with the local surface ice flow direction, qualitatively consistent with measurements in East Antarctica. Combined with other radio echo sounding data, we conclude that observed birefringent asymmetries at South Pole are generated entirely in the lower half of the ice sheet. By contrast, birefringent asymmetries are observed at shallow depths in East Antarctica.The authors particularly thank Chris Allen and John Paden (University of Kansas), John Ralston (University of Kansas), Rebecca Boon (Pennsylvania State University), Joe MacGregor (University of Texas), and Kenny Matsuoka (Norwegian Polar Institute) for very helpful discussions, as well as our colleagues on the RICE and ANITA experiments. We also thank Andy Bricker of Lawrence High School (Lawrence, KS) for his assistance working with Lawrence High School students who performed essential antenna calibrations. This work was supported by the National Science Foundation’s Office of Polar Programs (grant OPP-0826747) and QuarkNet programs. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation

Effect of animal fats on the physical properties of palm fat

Palm fat is one of the most commonly used fats in food industry. The main role of palm fat is to develop the desired texture of food products. Fat blends were developed to find the most appropriate mixture fitting the technological needs. In our work palm mid fraction (PMF) was mixed with anhydrous milk fat (AMF), goose fat (G), and lard (L) in a 1:1 ratio. Anhydrous milk fat represents fat consisting of a wide range of fatty acids. Goose fat is a soft, easily melting fat, and lard is characterized as animal fat with wide melting temperature interval. The measurements aimed to establish the miscibility of the fats and the effect of animal fats on the melting-solidification profile of palm mid fraction. SFC vs temperature curves, Differential Scanning Calorimetry (DSC) melting thermograms describe the melting profile of the samples. Isotherm crystallization by SFC vs time curves and DSC cooling thermograms were measured to characterize the solidification of pure fats and the blends. Since the SFC curves did not show crosspoints we concluded that fats blended in a 1:1 ratio were miscible. Anhydrous milk fat strongly modified the properties of palm mid fraction, the blend became similar to anhydrous milk fat. Goose fat had no strong modification effect on palm mid fraction and could be considered as a softening agent. The effect of lard was complex: melting and solidification behaviour of the blend differed from the characteristics of both parent fats

New limits for neutrinoless tau decays

Neutrinoless 3-prong tau lepton decays into a charged lepton and either two charged particles or one neutral meson have been searched for using 4.79fb^(-1) of data collected with the CLEO II detector at Cornell Electron Storage Ring. This analysis represents an update of a previous study and the addition of six decay channels. In all channels the numbers of events found are compatible with background estimates and branching fraction upper limits are set for 28 different decay modes. These limits are either more stringent than those set previously or represent the first attempt to find these decays

Search for color-suppressed B hadronic decay processes at the Υ(4S) resonance

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.57.5363.Using 3.1fb(-1) of data accumulated at the Υ(4S) by the CLEO-II detector, corresponding to 3.3×10(6) BB¯ pairs, we have searched for the color-suppressed B hadronic decay processes B(0)→D(0)(D*(0))X(0), where X(0) is a light neutral meson π(0), ρ(0(, η, η′ or ω. The D*(0) mesons are reconstructed in D*(0)→D(0)π(0) and the D(0) mesons in D(0)→K(-)π(+), K(-)π(+)π(0) and K(-)π(+)π(+)π(-) decay modes. No obvious signal is observed. We set 90% C.L. upper limits on these modes, varying from 1.2×10(-4) for B(0)→D(0)π(0) to 1.9×10(-3) for B(0)→D*(0)η′

Search for astrophysical tau neutrinos in three years of IceCube data

The IceCube Neutrino Observatory has observed a diffuse flux of TeV-PeV astrophysical neutrinos at 5.7σ significance from an all-flavor search. The direct detection of tau neutrinos in this flux has yet to occur. Tau neutrinos become distinguishable from other flavors in IceCube at energies above a few hundred TeV, when the cascade from the tau neutrino charged current interaction becomes resolvable from the cascade from the tau lepton decay. This paper presents results from the first dedicated search for tau neutrinos with energies between 214 TeV and 72 PeV in the full IceCube detector. The analysis searches for IceCube optical sensors that observe two separate pulses in a single event—one from the tau neutrino interaction and a second from the tau decay. No candidate events were observed in three years of IceCube data. For the first time, a differential upper limit on astrophysical tau neutrinos is derived around the PeV energy region, which is nearly 3 orders of magnitude lower in energy than previous limits from dedicated tau neutrino searches

Hadronic transitions Υ(2S)→Υ(1S)

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.58.052004.Using a 73.6pb(-1) data sample of Υ(2S) events collected with the CLEO II detector at the Cornell Electron Storage Ring, we have investigated the hadronic transitions between the Υ(2S) and the Υ(1S). The dipion transition Υ(2S)→Υ(1S)π(+)π(-) was studied using two different analysis techniques. Selecting events in which Υ(1S)→e(+)e(-),μ(+)μ(-) (“exclusive” analysis), and using the Υ(1S) leptonic branching fractions world averages from the PDG review, we obtained B(Υ(2S)→Υ(1S)π(+)π(-))=0.189±0.004±0.010, while using a method allowing Υ(1S)→anything (“inclusive” analysis) we obtained B(Υ(2S)→Υ(1S)π(+)π(-))=0.196±0.002±0.010. The appropriate weighted average of the two measurements gives B(Υ(2S)→Υ(1S)π(+)π(-))=0.192±0.002±0.010. Combining the exclusive and inclusive results we derive the Υ(1S) leptonic branching fractions Bee=0.0229±0.0008±0.0011 and Bμμ=0.0249±0.0008±0.0013. We also studied Υ(2S)→Υ(1S)π(0)π(0) and obtained B(Υ(2S)→Υ(1S)π(0)π(0))=0.092±0.006±0.008. Parameters of the ππ system (dipion invariant mass spectra, angular distributions) were analyzed and found to be consistent with current theoretical models. Lastly, we searched for the η and single π(0) transitions and obtained the 90% confidence level upper limits B(Υ(2S)→Υ(1S)η)<0.0028 and B(Υ(2S)→Υ(1S)π(0))<0.0011

Neutrino oscillation studies with IceCube-DeepCore

IceCube, a gigaton-scale neutrino detector located at the South Pole, was primarily designed to search for astrophysical neutrinos with energies of PeV and higher. This goal has been achieved with the detection of the highest energy neutrinos to date. At the other end of the energy spectrum, the DeepCore extension lowers the energy threshold of the detector to approximately 10 GeV and opens the door for oscillation studies using atmospheric neutrinos. An analysis of the disappearance of these neutrinos has been completed, with the results produced being complementary with dedicated oscillation experiments. Following a review of the detector principle and performance, the method used to make these calculations, as well as the results, is detailed. Finally, the future prospects of IceCube-DeepCore and the next generation of neutrino experiments at the South Pole (IceCube-Gen2, specifically the PINGU sub-detector) are briefly discussed.SCOAP

Experimental tests of lepton universality in τ decay

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.55.2559.The branching fractions for τ→eνν(τ), μνν(τ), and hν(τ) are measured using data collected with the CLEO detector at the CESR e(+)e(-) collider: Be=0.1776±0.0006±0.0017, Bμ=0.1737±0.0008±0.0018, and B(h)=0.1152±0.0005±0.0012, where the first error is statistical, the second systematic, and h refers to either a charged π or K. Also measured is the τ mass, mτ=(1778.2±1.4) MeV. Lepton universality is affirmed by the relative branching fractions (B(μ)/B(e)=0.9777±0.0063±0.0087, B(h)/B(e)=0.6484±0.0041±0.0060) and the charged-current gauge coupling-constant ratios (g(μ)/g(e)=1.0026±0.0055, g(τ)/g(μ)=0.9990±0.0098). The τ mass result may be recast as a τ neutrino mass limit, m(ν)(τ)<60 MeV at 95% C.L

Measurements of the meson-photon transition form factors of light pseudoscalar mesons at large momentum transfer

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.57.33.Using the CLEO II detector, we have measured the differential cross sections for exclusive two-photon production of light pseudoscalar mesons π(0), η, and η′. From our measurements we have obtained the form factors associated with the electromagnetic transitions γ*γ⃗ meson. We have measured these form factors in the momentum transfer ranges from 1.5 to 9, 20, and 30GeV(2) for π(0), η, and η′, respectively, and have made comparisons to various theoretical predictions

The Search for Transient Astrphysical Neutrino Emission With Icecube-Deepcore

We present the results of a search for astrophysical sources of brief transient neutrino emission using IceCube and DeepCore data acquired between 2012 May 15 and 2013 April 30. While the search methods employed in this analysis are similar to those used in previous IceCube point source searches, the data set being examined consists of a sample of predominantly sub-TeV muon-neutrinos from the Northern Sky (−5$^\circ \lt \delta \lt 90^\circ$) obtained through a novel event selection method. This search represents a first attempt by IceCube to identify astrophysical neutrino sources in this relatively unexplored energy range. The reconstructed direction and time of arrival of neutrino events are used to search for any significant self-correlation in the data set. The data revealed no significant source of transient neutrino emission. This result has been used to construct limits at timescales ranging from roughly 1 s to 10 days for generic soft-spectra transients. We also present limits on a specific model of neutrino emission from soft jets in core-collapse supernovae