749 research outputs found
Theta dependence of CP^9 model
We apply to the model two recently proposed numerical techniques for
simulation of systems with a theta term. The algorithms, successfully tested in
the strong coupling limit, are applied to the weak coupling region. The results
agree and errors have been evaluated and are at % level. The results scale well
with the renormalization group equation and show that, for in presence
of a theta term, CP symmetry is spontaneously broken at in the
continuum limit.Comment: 4 pages, 4 figure
Reconstruction and actual trends of landslide activities in BruustâHaltiwald, Horw, canton of Lucerne, Switzerland
A spatiotemporal reconstruction of slope movements on the
edge of Lake Lucerne near the municipality of Horw, canton of Lucerne, is
presented. The reconstruction was realized by analyzing growth reactions of
beech (Fagus sylvatica L.) and fir (Abies alba Mill.) trees growing on this slope. Before
dendrochronological sampling, a detailed geomorphological mapping of the
landslide was conducted with the aim to determine the spatial extent of the
sliding area. For tree-ring analyses, 124Â increment cores from 62Â trees were
analyzed following standard techniques of dendrogeomorphology. In addition,
long micro-sections were prepared from the entire cores to extend the common
eccentricity analyses by microscopic determination of the onset of reaction
wood in fir and beech. Results clearly show that the area is moving at
least since 1948. A significant concentration of events was observed between
the years 1990 and 2000 as well as after 2006. The definition of a threshold
to define events using an eccentricity index alone is problematic and needs
to be adapted to specific site conditions. For this reason, we recommend always combining the application of an eccentricity index with a detailed
visual (anatomical) inspection to check for the occurrence of reaction wood.</p
Light hadron spectrum and quark masses in QCD with two flavors of dynamical quarks
We present updated results of the CP-PACS calculation of the light hadron
spectrum in full QCD. Simulations are made with an RG-improved
gauge action and a tadpole-improved clover quark action for sea quark masses
corresponding to --0.6 and the lattice
spacing --0.09 fm. A comparison of the full QCD spectrum with new
quenched results, obtained with the same improved action, shows clearly the
existence of sea quark effects in vector meson masses. Results for light quark
masses in QCD are also presented.Comment: Latex 3 pages, 6 PostScript figures, Talk presented at LATTICE99(QCD
Spectrum and Quark Masses
Heavy Quarkonia from Anisotropic and Isotropic Lattices
We report on recent results for the spectrum of heavy quarkonia. Using coarse
and anisotropic lattices we achieved an unprecedented control over statistical
and systematic errors for higher excited states such as exotic hybrid states.
In a parallel study on isotropic lattices we also investigate the effect of two
dynamical flavours on the spin structure of charmonium and bottomonium for
several symmetric lattices.Comment: LATTICE'99 (heavy quarks), 3 pages, 3 figure
Eta meson mass and topology in QCD with two light flavors
We present results for the mass of the flavor singlet meson calculated on
two-flavor full QCD configurations generated by the CP-PACS full QCD project.
We also investigate topological charge fluctuations and their dependence on the
sea quark mass.Comment: LATTICE99 (QCD Spectrum and Quark Masses), LaTeX(espcrc2.sty), 3
pages, 6 eps figure
Equation of state in finite-temperature QCD with improved Wilson quarks
We study finite-temperature phase transition and equation of state for
two-flavor QCD at using an RG-improved gauge action and a
meanfield-improved clover quark action. The pressure is computed using the
integral method. The O(4) scaling of chiral order parameter is also examined.Comment: LATTICE99(finite temperature), 3 page
Perfect topological charge for asymptotically free theories
The classical equations of motion of the perfect lattice action in
asymptotically free spin and gauge models possess scale invariant
instanton solutions. This property allows the definition of a topological
charge on the lattice which is perfect in the sense that no topological defects
exist. The basic construction is illustrated in the O(3) non--linear
--model and the topological susceptibility is measured to high
precision in the range of correlation lengths . Our results
strongly suggest that the topological susceptibility is not a physical quantity
in this model.Comment: Contribution to Lattice'94, 3 pages PostScript, uuencoded compresse
Responding to Race Related Trauma: Counseling and Research Recommendations to Promote Post-Traumatic Growth when Counseling African American Males
The application of Post-Traumatic Growth, a resiliency based approach, for counselors working with African-American male clients who have experienced race-based trauma is described. The role of cognitive processing and meaning making are reviewed. Implications for counseling, education and research are provided
Heavy-light decay constants from clover heavy quark action in QCD with two flavors of dynamical quarks
We present results on an analysis of the decay constants f_B and f_Bs with
two flavours of sea quark. The calculation has been carried out on 3 different
bare gauge couplings and 4 sea quark masses at each gauge coupling, with
m_pi/m_rho ranging from 0.8 to 0.6. We employ the Fermilab formalism to perform
calculations with heavy quarks whose mass is in the range of the b-quark. A
detailed comparison with a quenched calculation using the same action is made
to elucidate the effects due to the sea quarks.Comment: Contribution to Lattice 99 (Heavy Quarks). Latex file, uses
espcrc2.sty and epsf.sty. 3 pages, 3 encapsulated postscript figure
Distinct balance of excitation and inhibition in an interareal feedforward and feedback circuit of mouse visual cortex
Mouse visual cortex is subdivided into multiple distinct, hierarchically organized areas that are interconnected through feedforward (FF) and feedback (FB) pathways. The principal synaptic targets of FF and FB axons that reciprocally interconnect primary visual cortex (V1) with the higher lateromedial extrastriate area (LM) are pyramidal cells (Pyr) and parvalbumin (PV)-expressing GABAergic interneurons. Recordings in slices of mouse visual cortex have shown that layer 2/3 Pyr cells receive excitatory monosynaptic FF and FB inputs, which are opposed by disynaptic inhibition. Most notably, inhibition is stronger in the FF than FB pathway, suggesting pathway-specific organization of feedforward inhibition (FFI). To explore the hypothesis that this difference is due to diverse pathway-specific strengths of the inputs to PV neurons we have performed subcellular Channelrhodopsin-2-assisted circuit mapping in slices of mouse visual cortex. Whole-cell patch-clamp recordings were obtained from retrobead-labeled FF(V1âLM)- and FB(LMâV1)-projecting Pyr cells, as well as from tdTomato-expressing PV neurons. The results show that the FF(V1âLM) pathway provides on average 3.7-fold stronger depolarizing input to layer 2/3 inhibitory PV neurons than to neighboring excitatory Pyr cells. In the FB(LMâV1) pathway, depolarizing inputs to layer 2/3 PV neurons and Pyr cells were balanced. Balanced inputs were also found in the FF(V1âLM) pathway to layer 5 PV neurons and Pyr cells, whereas FB(LMâV1) inputs to layer 5 were biased toward Pyr cells. The findings indicate that FFI in FF(V1âLM) and FB(LMâV1) circuits are organized in a pathway- and lamina-specific fashion
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