2,000 research outputs found

    Axial vector current in an electromagnetic field and low-energy neutrino-photon interactions

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    An expression for the axial vector current in a strong, slowly varying electromagnetic field is obtained. We apply this expression to the construction of the effective action for low-energy neutrino-photon interactions.Comment: 6 pages, references updated, final version to appear in Phys. Rev.

    The effects of a 12-Month weight loss intervention on cognitive outcomes in adults with overweight and obesity

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    Obesity is associated with poorer executive functioning and reward sensitivity. Yet, we know very little about whether weight loss through diet and/or increased exercise engagement improves cognitive function. This study evaluated whether weight loss following a dietary and exercise intervention was associated with improved cognitive performance. We enrolled 125 middle-aged adults with overweight and obesity (98 female) into a 12-month behavioral weight loss intervention. Participants were assigned to one of three groups: energy-restricted diet alone, an energy-restricted diet plus 150 min of moderate intensity exercise per week or an energy restricted diet plus 250 min of exercise per week. All participants completed tests measuring executive functioning and/or reward sensitivity, including the Iowa Gambling Task (IGT). Following the intervention, weight significantly decreased in all groups. A MANCOVA controlling for age, sex and race revealed a significant multivariate effect of group on cognitive changes. Post-hoc ANCOVAs revealed a Group x Time interaction only on IGT reward sensitivity, such that the high exercise group improved their performance relative to the other two intervention groups. Post-hoc ANCOVAs also revealed a main effect of Time, independent of intervention group, on IGT net payoff score. Changes in weight were not associated with other changes in cognitive performance. Engaging in a high amount of exercise improved reward sensitivity above and beyond weight loss alone. This suggests that there is additional benefit to adding exercise into behavioral weight loss regimens on executive functioning, even without additional benefit to weight loss

    Weighted azimuthal asymmetries in a diquark spectator model

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    We analytically calculate weighted azimuthal asymmetries in semi-inclusive lepton-nucleon deep-inelastic scattering and Drell-Yan processes, using transverse-momentum-dependent partonic densities obtained in a diquark spectator model. We compare the asymmetries with available preliminary experimental data, in particular for the Collins and the Sivers effect. We make predictions for other cases of interest in running and planned experiments.Comment: 21 pages, 13 (multiple) figures in eps format, RevTeX

    An Automatic Invisible Axion In The SUSY Preon Model

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    It is shown that the recently proposed preon model which provides a unified origin of the diverse mass scale and an explanation of family replication as well as of inter-family mass-hierarchy, possesses a Peccei-Quinn symmetry whose spontaneous breaking leads to an automatic invisible axion. Existence of the PQ-symmetry is simply a consequence of supersymmetry and requirement of minimality in the field-content and interactions, which propose that the lagrangian should possess only those terms which are dictated by the gauge principle and no others. In addition to the axion, the model also generates two superlight Goldstone bosons and their superpartners which are cosmologically safe.Comment: (TeX file) 16 Page

    Road environment modeling using robust perspective analysis and recursive Bayesian segmentation

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    Recently, vision-based advanced driver-assistance systems (ADAS) have received a new increased interest to enhance driving safety. In particular, due to its high performance–cost ratio, mono-camera systems are arising as the main focus of this ïŹeld of work. In this paper we present a novel on-board road modeling and vehicle detection system, which is a part of the result of the European I-WAY project. The system relies on a robust estimation of the perspective of the scene, which adapts to the dynamics of the vehicle and generates a stabilized rectiïŹed image of the road plane. This rectiïŹed plane is used by a recursive Bayesian classi- ïŹer, which classiïŹes pixels as belonging to different classes corresponding to the elements of interest of the scenario. This stage works as an intermediate layer that isolates subsequent modules since it absorbs the inherent variability of the scene. The system has been tested on-road, in different scenarios, including varied illumination and adverse weather conditions, and the results have been proved to be remarkable even for such complex scenarios

    Transverse Momentum Dependent Parton Distribution/Fragmentation Functions at an Electron-Ion Collider

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    We present a summary of a recent workshop held at Duke University on Partonic Transverse Momentum in Hadrons: Quark Spin-Orbit Correlations and Quark-Gluon Interactions. The transverse momentum dependent parton distribution functions (TMDs), parton-to-hadron fragmentation functions, and multi-parton correlation functions, were discussed extensively at the Duke workshop. In this paper, we summarize first the theoretical issues concerning the study of partonic structure of hadrons at a future electron-ion collider (EIC) with emphasis on the TMDs. We then present simulation results on experimental studies of TMDs through measurements of single spin asymmetries (SSA) from semi-inclusive deep-inelastic scattering (SIDIS) processes with an EIC, and discuss the requirement of the detector for SIDIS measurements. The dynamics of parton correlations in the nucleon is further explored via a study of SSA in D (`D) production at large transverse momenta with the aim of accessing the unexplored tri-gluon correlation functions. The workshop participants identified the SSA measurements in SIDIS as a golden program to study TMDs in both the sea and valence quark regions and to study the role of gluons, with the Sivers asymmetry measurements as examples. Such measurements will lead to major advancement in our understanding of TMDs in the valence quark region, and more importantly also allow for the investigation of TMDs in the sea quark region along with a study of their evolution.Comment: 44 pages 23 figures, summary of Duke EIC workshop on TMDs accepted by EPJ

    Gauging U(1) symmetries and the number of right-handed neutrinos

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    In this letter we consider that assuming: a) that the only left-handed neutral fermions are the active neutrinos, b) that B−LB-L is a gauge symmetry, and c) that the LL assignment is restricted to the integer numbers, the anomaly cancellation imply that at least three right-handed neutrinos must be added to the minimal representation content of the electroweak standard model. However, two types of models arise: i) the usual one where each of the three identical right-handed neutrinos has total lepton number L=1; ii) and the other one in which two of them carry L=4 while the third one carries L=−5L=-5.Comment: Published version in PLB forma

    Seesaw tau lepton mass and calculable neutrino masses in a 3-3-1 model

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    In a version of the 3-3-1 model proposed by Duong and Ma the introduction of the scalar sextet for giving mass to the charged leptons is avoided by adding a singlet charged lepton. We show that in this case the τ\tau lepton gains mass through a seesaw--like mechanism. Besides we show how to generate neutrino masses at the tree and at the 1-loop level with the respective Maki-Nakagawa-Sakata leptonic mixing matrices.Comment: revtex, 5 pages and one eps figure. Published versio

    Stabilities of nanohydrated thymine radical cations: insights from multiphoton ionization experiments and ab initio calculations

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    Multi-photon ionization experiments have been carried out on thymine-water clusters in the gas phase. Metastable H2O loss from T+(H2O)n was observed at n ≄ 3 only. Ab initio quantum-chemical calculations of a large range of optimized T+(H2O)n conformers have been performed up to n = 4, enabling binding energies of water to be derived. These decrease smoothly with n, consistent with the general trend of increasing metastable H2O loss in the experimental data. The lowest-energy conformers of T+(H2O)3 and T+(H2O)4 feature intermolecular bonding via charge-dipole interactions, in contrast with the purely hydrogen-bonded neutrals. We found no evidence for a closed hydration shell at n = 4, also contrasting with studies of neutral clusters

    Initial Commissioning of a Water-to-Water GHP System in KIER

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    GHP(Geothermal Heat Pump) system has been extensively disseminated due to the recent increasing demand of the new and renewable energy in Korea. However, the system reliability issues have been key barriers to ensure system performance as initially designed. This paper introduces a systematic method to verify its actually operating performance of a water to water GHP system. The main idea is to compare the actual performance with the manufacture data and then to reduce the gap between the actual and the manufacture data. The key result of this study is the development of a simplified GHP performance verification technique using the ISO standard based manufacture data. The manufacture performance data includes the information of EWT(entering water temperature), LWT(leaving water temperature), capacity, flow rate, power and COP. This technique has been verified to a w to w GHP system designed and installed at KIER site. The verification study showed that actual performance was lower than Manufacture data. And then the refrigerant was recharged and the compressor and the expansion valve were replaced. As a result, we can easily identify the GHP system problems and heating and cooling COP has been increased 25.26%, 18.24%
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