23,259 research outputs found
Beyond-the-Standard-Model matrix elements with the gradient flow
At the Forschungszentrum Juelich (FZJ) we have started a long-term program
that aims to determine beyond-the-Standard-Model (BSM) matrix elements using
the gradient flow, and to understand the impact of BSM physics in nucleon and
nuclear observables. Using the gradient flow, we propose to calculate the QCD
component of key beyond the Standard Model (BSM) matrix elements related to
quark and strong theta CP violation and the strange content within the nucleon.
The former set of matrix elements impacts our understanding of Electric Dipole
Moments (EDMs) of nucleons and nuclei (a key signature of BSM physics), while
the latter contributes to elastic recoil of Dark Matter particles off nucleons
and nuclei. If successful, these results will lay the foundation for extraction
of BSM observables from future low-energy, high-intensity and high-accuracy
experimental measurements.Comment: 7 pages, 2 figures, presented at the 32nd International Symposium on
Lattice Field Theory (Lattice 2014). Correct version of proceedings.
Different wording of few paragraphs and different notation on few formulas.
Added 1 referenc
First-principle calculations of Dark Matter scattering off light nuclei
We study the scattering of Dark Matter particles off various light nuclei
within the framework of chiral effective field theory. We focus on scalar
interactions and include one- and two-nucleon scattering processes whose form
and strength are dictated by chiral symmetry. The nuclear wave functions are
calculated from chiral effective field theory interactions as well and we
investigate the convergence pattern of the chiral expansion in the nuclear
potential and the Dark Matter-nucleus currents. This allows us to provide a
systematic uncertainty estimate of our calculations. We provide results for
H, H, and He nuclei which are theoretically interesting and
the latter is a potential target for experiments. We show that two-nucleon
currents can be systematically included but are generally smaller than
predicted by power counting and suffer from significant theoretical
uncertainties even in light nuclei. We demonstrate that accurate high-order
wave functions are necessary in order to incorporate two-nucleon currents. We
discuss scenarios in which one-nucleon contributions are suppressed such that
higher-order currents become dominant
Political attention to environmental issues: analyzing policy punctuations in the Netherlands
Effect of Surgery on Quality of Life with Operable Breast Cancer in Limited Resource Environments: Reply
Ó The Author(s) 2010. This article is published with open access at Springerlink.com We thank Purvi Thakkar et al. for their comments on our article [1]. It is good to see that our results are reproducible. The reported decrease in quality of life may be explained by the fact that a different questionnaire was used. The FACT-B is a disease-specific questionnaire that inquires more into functioning than into satisfaction with functioning. The primary goal of our study was to present surgeons with other factors than only the clinical parameters, such as tumor size, that can help in the decisional process. We hope that more surgeons will assess the personality of a woman with early-stage breast cancer and use this as additional information when counseling her about possible breast cancer treatment modalities. Open Access This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited
Persistence of the valence bond glass state in the double perovskites Ba2-xSrxYMoO6
Peer reviewedPublisher PD
Baryon mass splittings and strong CP violation in SU(3) chiral perturbation theory
We study SU(3) flavor-breaking corrections to the relation between the octet baryon masses and the nucleonmeson CP-violating interactions induced by the QCD (theta) over bar term. We work within the framework of SU(3) chiral perturbation theory andwork through next-to-next-to-leading order in the SU(3) chiral expansion, which isO(m(q)(2)). At lowest order, the CP-odd couplings induced by the QCD (theta) over bar term are determined bymass splittings of the baryon octet, the classic result of Crewther et al. [Phys. Lett. B 88, 123 (1979)]. We show that for each isospin-invariant CP-violating nucleon-meson interaction there exists one relation that is respected by loop corrections up to the order we work, while other leading-order relations are violated. With these relations we extract a precise value of the pion-nucleon coupling (g) over bar (0) by using recent lattice QCD evaluations of the proton-neutron mass splitting. In addition, we derive semiprecise values for CP-violating coupling constants between heaviermesons and nucleons with similar to 30% uncertainty and discuss their phenomenological impact on electric dipole moments of nucleons and nuclei
The effect of core polarization on longitudinal form factors in B
Electron scattering Coulomb form factors for the single-particle quadrupole
transitions in -shell B nucleus have been studied. Core polarization
effects are included through a microscopic theory that includes excitations
from the core orbits up to higher orbits with 2 excitations. The
modified surface delta interaction (MSDI) is employed as a residual
interaction. The effect of core polarization is found essential in both the
transition strengths and momentum transfer dependence of form factors, and
gives a remarkably good agreement with the measured data with no adjustable
parameters.Comment: 4 pages, 5 figure
Processing multiple non-adjacent dependencies: evidence from sequence learning
Processing non-adjacent dependencies is considered to be one of the hallmarks of human language. Assuming that sequence-learning tasks provide a useful way to tap natural-language-processing mechanisms, we cross-modally combined serial reaction time and artificial-grammar learning paradigms to investigate the processing of multiple nested (A(1)A(2)A(3)B(3)B(2)B(1)) and crossed dependencies (A(1)A(2)A(3)B(1)B(2)B(3)), containing either three or two dependencies. Both reaction times and prediction errors highlighted problems with processing the middle dependency in nested structures (A(1)A(2)A(3)B(3-)B(1)), reminiscent of the 'missing-verb effect' observed in English and French, but not with crossed structures (A(1)A(2)A(3)B(1-)B(3)). Prior linguistic experience did not play a major role: native speakers of German and Dutch-which permit nested and crossed dependencies, respectively-showed a similar pattern of results for sequences with three dependencies. As for sequences with two dependencies, reaction times and prediction errors were similar for both nested and crossed dependencies. The results suggest that constraints on the processing of multiple non-adjacent dependencies are determined by the specific ordering of the non-adjacent dependencies (i.e. nested or crossed), as well as the number of non-adjacent dependencies to be resolved (i. e. two or three). Furthermore, these constraints may not be specific to language but instead derive from limitations on structured sequence learning.Netherlands Organisation of Scientific Research (NWO) [446-08-014]; Max Planck Institute for Psycholinguistics; Donders Institute for Brain, Cognition and Behaviour; Fundacao para a Ciencia e Tecnologia (IBB/CBME, LA, FEDER/POCI) [PTDC/PSI-PCO/110734/2009]; Stockholm Brain Institute; Vetenskapsradet; Swedish Dyslexia Foundation; Hedlunds Stiftelse; Stockholm County Council (ALF, FoUU)info:eu-repo/semantics/publishedVersio
Dietary assessment methods for micronutrient intake in elderly people: a systematic review
The European micronutrient recommendations aligned (EURRECA) Network of Excellence seeks to establish clear guidelines for assessing the validity of reported micronutrient intakes among vulnerable population groups. A systematic literature review identified studies validating the methodology used in elderly people for measuring usual dietary micronutrient intake. The quality of each validation study selected was assessed using a EURRECA-developed scoring system. The validation studies were categorised according to whether the reference method applied reflected short-term intake ( <7 d), long-term intake ( = 7 d) or used biomarkers (BM). A correlation coefficient for each micronutrient was calculated from the mean of the correlation coefficients from each study weighted by the quality of the study. Thirty-three papers were selected, which included the validation of twenty-five different FFQ, six diet histories (DH), one 24-h recall (24HR) and a videotaped dietary assessment method. A total of five publications analysed BM, which were used to validate four FFQ, and one 24HR, presenting very good correlations only for vitamin E. The analysis of weighted correlation coefficients classified by FFQ or DH showed that most of the micronutrients had higher correlations when the DH was used as the dietary method. Comparing only FFQ results showed very good correlations for measuring short-term intakes of riboflavin and thiamin and long-term intakes of P and Mg. When frequency methods are used for assessing micronutrient intake, the inclusion of dietary supplements improves their reliability for most micronutrients
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