Reanalysis of the GALLEX solar neutrino flux and source experiments

After the completion of the gallium solar neutrino experiments at the Laboratori Nazionali del Gran Sasso (GALLEX}: 1991-1997; GNO: 1998-2003) we have retrospectively updated the GALLEX results with the help of new technical data that were impossible to acquire for principle reasons before the completion of the low rate measurement phase (that is, before the end of the GNO solar runs). Subsequent high rate experiments have allowed the calibration of absolute internal counter efficiencies and of an advanced pulse shape analysis for counter background discrimination. The updated overall result for GALLEX (only) is (73.4 +7.1 -7.3) SNU. This is 5.3% below the old value of (77.5 + 7.5 -7.8) SNU (PLB 447 (1999) 127-133) with a substantially reduced error. A similar reduction is obtained from the reanalysis of the 51Cr neutrino source experiments of 1994/1995.Comment: Accepted by Physics Letters B January 13, 201

Sifting data in the real world

In the real world, experimental data are rarely, if ever, distributed as a normal (Gaussian) distribution. As an example, a large set of data--such as the cross sections for particle scattering as a function of energy contained in the archives of the Particle Data Group--is a compendium of all published data, and hence, unscreened. Inspection of similar data sets quickly shows that, for many reasons, these data sets have many outliers--points well beyond what is expected from a normal distribution--thus ruling out the use of conventional $\chi^2$ techniques. This note suggests an adaptive algorithm that allows a phenomenologist to apply to the data sample a sieve whose mesh is coarse enough to let the background fall through, but fine enough to retain the preponderance of the signal, thus sifting the data. A prescription is given for finding a robust estimate of the best-fit model parameters in the presence of a noisy background, together with a robust estimate of the model parameter errors, as well as a determination of the goodness-of-fit of the data to the theoretical hypothesis. Extensive computer simulations are carried out to test the algorithm for both its accuracy and stability under varying background conditions.Comment: 29 pages, 13 figures. Version to appear in Nucl. Instr. & Meth.

Interplay between breathing mode distortion and magnetic order in rare-earth nickelates RRNiO3_3 within DFT+UU

We present a systematic density functional theory (DFT) plus Hubbard $U$ study of structural trends and the stability of different magnetically ordered states across the rare-earth nickelate series, $R$NiO$_3$, with $R$ from Lu to La. In particular, we investigate how the magnetic order, the change of the rare-earth ion, and the Hubbard interaction $U$ are affecting the bond-length disproportionation between the nickel sites. Our results show that structural parameters can be obtained that are in very good agreement with present experimental data, and that DFT+$U$ is in principle able to capture the most important structural trends across the nickelate series. However, the amplitude of the bond-length disproportionation depends very strongly on the specific value used for the Hubbard $U$ parameter and also on the type of magnetic order imposed in the calculation. Regarding the relative stability of different magnetic orderings, a realistic antiferromagnetic order, consistent with the experimental observations, is favored for small $U$ values, and becomes more and more favorable compared to the ferromagnetic state towards the end of the series (i.e., towards $R$=Pr). Nevertheless, it seems that the stability of the ferromagnetic state is generally overestimated within the DFT+$U$ calculations. Our work provides a profound starting point for more detailed experimental investigations, and also for future studies using more advanced computational techniques such as, e.g., DFT combined with dynamical mean-field theory.Comment: 13 pages, 11 figures, 1 tabl

Total and phosphorylated tau proteins: Evaluation as core biomarker candidates in frontotemporal dementia

An ever increasing number of patients with neurodegenerative disorders calls for the evaluation of potential diagnostic markers that allow an early diagnosis and an early initiation of specific therapy. Clinical diagnosis of Alzheimer's disease (AD), the most common neurodegenerative disorder, reaches 80-90% accuracy upon autopsy in specialized clinical centers. Diagnosis of AD in early clinical or preclinical stages is far less accurate, as is the differential diagnosis between AD and other primary dementias, such as frontotemporal dementia (FTD). Microtubule-associated tau protein is abnormally phosphorylated in AD and aggregates as paired helical filaments in neurofibrillary tangles. Recently, immunoassays have been developed detecting tau phosphorylated at specific epitopes in cerebrospinal fluid (CSF). Four years of clinical research consistently demonstrate that CSF phosphorylated tau (p-tau) is highly increased in AD compared to healthy controls and may differentiate AD from its most relevant differential diagnoses. Tau phosphorylated at threonine 231 (p-tau(231)) shows excellent differentiation between AD and FTD, whereas serine 181 (p-tau(181)) enhances accurate differentiation between AD and dementia with Lewy bodies. Moreover, p-tau(231) levels decline with disease progression, correlating with cognitive performance at baseline. Total tau (t-tau) is regarded as a general marker of neurodegeneration for evaluation in future population-based studies. p-tau(231) and p-tau(181) yield excellent discrimination between AD and non-AD dementias including FTD, exceeding the differential diagnostic and prognostic accuracy of t-tau. Therefore, p-tau is a core biological marker candidate for future evaluation in large national and international multicenter networks. Copyright (C) 2004 S. Karger AG, Basel

Gamma Hadron Separation using Pairwise Compactness Method with HAWC

The High-Altitude Water Cherenkov (HAWC) Observatory is a ground based air-shower array deployed on the slopes of Volcan Sierra Negra in the state of Puebla, Mexico. While HAWC is optimized for the detection of gamma-ray induced air-showers, the background flux of hadronic cosmic-rays is four orders of magnitude greater, making background rejection paramount for gamma-ray observations. On average, gamma-ray and cosmic-ray showers are characterized by different topologies at ground level. We will present a method to identify the primary particle type in an air-shower that uses the spatial relationship of triggered PMTs (or "hits") in the detector. For a given event hit-pattern on the HAWC array, we calculate the mean separation distance of the hits for a subset of hit pairs weighted by their charges. By comparing the mean charge and mean separating distance for the selected hits, we infer the identity of the event's primary. We will report on the efficiency for identifying gamma-rays and the performance of the technique with simulation.Comment: Presented at the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. See arXiv:1508.03327 for all HAWC contribution

Data-matched filter

After amplification and normalization, incoming data bits are fed, alternately, to pair of integrators. While one integrator is operating, content of other is on hold, sample, and dump. Clock derived in bit-timing extractor times and controls integrators. Frequency of clock is one-half data rate

The Extraction of the Gluon Density from Jet Production in Deeply Inelastic Scattering

The prospects of a direct extraction of the proton's gluon density in next-to-leading order via jet rates in deeply inelastic scattering are studied. The employed method is based on the Mellin transform, and can be applied, in principle, to all infra-red-safe observables of hadronic final states. We investigate the dependence of the error band on the extracted gluon distribution on the statistical and systematic error of the data.Comment: 5 pages (Latex); 2 figures are included via epsfig; contribution to the workshop ``Future Physics at HERA'' at DESY, Hamburg, 1995/96; to be published in the proceedings; compressed postscript version also available at http://wwwcn.cern.ch/~graudenz/publications.htm

The Gate-Resonance Model - The interface of policy, media and the public in technology conflicts

The gate/resonance model provides an analytical frame for the description of technology conflicts. It offers an analytical scheme to conceptualise the interaction between public opinion, interest representing organisations, the media and the political system. The model distinguishes structural elements, functional elements and processes. Structural elements are the public with sub-publics and representational fields, the regulatory system with its institutions, intermediary organisations representing interests and bridging the gap between the public(s) and the regulatory system, the regulatory space and the media that mirror and participate in interest conflicts. Functional elements are resources, which enable intermediary organisations to convey interests to regulation, and filters that prevent information overflow within regulatory institutions: the gate as a formal function selects information according to statutory criteria, detectors according to usefulness for the institution. Processes described are the movement of issue fields due to re-interpretation; resonance, the tuning-in on issue interpretation among different actors; mobilisation, the generation of political pressure through resonance; and policy change through the abol-ishment of established interest and actor equilibrium due to mobilisation and ensuing gate failure. The model is applied to the example of biotechnology conflicts.theoretical framework, technology conflict, interest representation, public mobilisation, resources