Search results for "group theory"
showing 10 items of 703 documents
f1(1285) decays into a0(980)π0, f0(980)π0 and isospin breaking
2016
We evaluate the decay width for the processes f1(1285) → π0a0(980) and f1(1285) → π0f0(980) taking into account that all three resonances are dynamically generated from the meson-meson interaction, the f1(1285) from K*K¯+cc and the a0 (980), f0(980) from πη, KK¯ and ππ, KK¯ respectively. We use a triangular mechanism similar to that of the η(1405)→ππη, which provides a decay width for f1 (1285) → π0a0 (980) with a branching fraction of the order of 30%, in agreement with experiment. At the same time we evaluate the decay width for the isospin forbidden f1(1285) → π0 f0(980), which appears when we consider different masses for the charged and neutral kaons, and show that it is much more supp…
Experiments on threshold pion electroproduction
2008
Experimental techniques to access the reactions p(e, e′ p)π0 and d(e, e′ d)π0 at low four momentum transfer and close to threshold are presented. For p(e, e′ p)π0 results at Q 2=0.1 GeV2/c 2 are given and compared to chiral perturbation theory. A new experimental program on d(e, e′ d)π0 is presented.
State-of-the-art density matrix renormalization group and coupled cluster theory studies of the nitrogen binding curve.
2004
We study the nitrogen binding curve with the density matrix renormalization group (DMRG) and single-reference and multireference coupled cluster (CC) theory. Our DMRG calculations use up to 4000 states and our single-reference CC calculations include up to full connected hextuple excitations. Using the DMRG, we compute an all-electron benchmark nitrogen binding curve, at the polarized, valence double-zeta level (28 basis functions), with an estimated accuracy of 0.03mE_h. We also assess the performance of more approximate DMRG and CC theories across the nitrogen curve. We provide an analysis of the relative strengths and merits of the DMRG and CC theory under different correlation condition…
Reprint of: Approximate Taylor methods for ODEs
2018
Abstract A new method for the numerical solution of ODEs is presented. This approach is based on an approximate formulation of the Taylor methods that has a much easier implementation than the original Taylor methods, since only the functions in the ODEs, and not their derivatives, are needed, just as in classical Runge–Kutta schemes. Compared to Runge–Kutta methods, the number of function evaluations to achieve a given order is higher, however with the present procedure it is much easier to produce arbitrary high-order schemes, which may be important in some applications. In many cases the new approach leads to an asymptotically lower computational cost when compared to the Taylor expansio…
Effect of Prime Type on Lexical Decision Time
1987
The present investigation concerns the issues of the control condition and type of related prime-target relationship operationalization in the lexical-decision paradigm. It is shown that the use of a row of asterisks produces strong inhibitory effects on reaction time to the target relative to a control condition formed with the word “neutro” (“neutral”). The operationalization of prime-target relatedness by means of association of category norms seems equally adequate, although category exemplars do not prime category exemplar targets. Both sets of data are discussed in relation to current research trends using lexical-decision time.
Dentoskeletal effects of class II malocclusion treatment with the modified Twin Block appliance
2019
Background The purpose of this study was to prospectively assess the dentoskeletal effect of a modified Twin Block appliance for treatment of class II malocclusions. Material and Methods Lateral cephalograms of 25 Class II malocclusion patients were compared to evaluate skeletal, dentoalveolar and soft tissue changes pre- and post-treatment with a modified Twin Block appliance. A total of 33 angular and linear variables were used for analysis. The differences were calculated at the start and end of treatment. The paired T test was performed to compare the cephalometric measurements before and after treatment. Results Compared the pre- and post- treatment measurements, there was a significan…
On the role of the upper part of words in lexical access: evidence with masked priming.
2012
More than 100 years ago, Huey (1908) indicated that the upper part of words was more relevant for perception than the lower part. Here we examined whether mutilated words, in their upper/lower portions (e.g., , , , ), can automatically access their word units in the mental lexicon. To that end, we conducted four masked repetition priming experiments with the lexical decision task. Results showed that mutilated primes produced a sizeable masked repetition priming effect. Furthermore, the magnitude of the masked repetition priming effect was greater when the upper part of the primes was preserved than when the lower portion was preserved –this was the case not only when the mutilated words we…
"Table 4" of "Measurement of the Collins and Sivers asymmetries on transversely polarised protons"
2007
The COLLINS asymmetry for negatively charged hadrons as a function of X.
"Table 5" of "Measurement of the Collins and Sivers asymmetries on transversely polarised protons"
2007
The COLLINS asymmetry for negatively charged hadrons as a function of Z.
"Table 15" of "Measurement of the Collins and Sivers asymmetries on transversely polarised protons"
2007
The COLLINS asymmetry for negatively charged hadrons as a function of Z for X > 0.05.