Search

Abstract The Higgs boson pair production at the LHC provides a probe to the Higgs boson self-coupling. The higher-order QCD corrections in this process are sizable and must be taken into account in comparison with data. Due to the small cross section, it is necessary to consider at least one of the Higgs bosons decaying to bottom quarks. The QCD corrections to the decay processes would also be important in such cases. We present a full calculation of the total and differential cross sections for the b b ¯ γγ $$ b\overline{b}\gamma \gamma $$ final state with next-to-leading order (NLO) QCD corrections. After applying typical kinematic cuts in the final state, we find that QCD NLO corrections in the decay decrease the LO result by 19% and reduce the scale uncertainties by a factor of two. The QCD corrections to the invariant mass m jjγγ distribution, the transverse momentum spectra of the leading bottom quark jet and photon are significant and can not be approximated by a constant factor.

Fostering students’ critical thinking (CT) is an increasing concern in EFL classrooms in China as many students struggle to utilize the skill, particularly in EFL reading comprehension classes. This study investigated the effects of graphic organizers (GOs) on 60 Chinese senior high school students’ CT skills (analyzing and generalizing) in EFL reading classes. This study adopted a quasi-experimental mixed-method research design involving an experiment and an interview. The findings of this study showed the positive impacts of GOs on students’ CT skills. After the intervention, the results of the experimental group improved significantly. The findings showed that GOs could effectively improve the analytical and generalization skills of Chinese high school English reading class students. The students in the experimental group reported that the instructions received were motivating, increased their comprehension, made them more focused on reading and aware of CT skills and how to apply them in real reading contexts. This study implies that teachers may consider GOs an alternative teaching tool to improve CT skills in English Language reading classes, particularly in EFL contexts. Guidelines for teachers to use the different types of GOs to promote critical thinking should also be prepared to ensure the effective use of GOs in promoting reading comprehension and critical thinking skills.

Abstract We consider, at order α s 2 $$ {\alpha}_s^2 $$ in the QCD coupling, top-quark pair production in the continuum at various center-of-mass energies and b-quark pair production at the Z resonance by (un)polarized electron and positron beams. For top quarks we compute the forward-backward asymmetry with respect to the top-quark direction of flight, the associated polar angle distribution, and we analyze the effect of beam polarization on the QCD corrections to the leading-order asymmetry. We calculate also the polarized forward-backward asymmetry. For b-quark production at the Z peak we explore different definitions of A FB. In particular, we analyze b jets defined by the Durham and the flavor-k T clustering algorithms. We compute the inclusive b-jet and two-jet asymmetry with respect to the b-jet direction. For the latter asymmetry the QCD corrections to order α s 2 $$ {\alpha}_s^2 $$ are small. That predestines it to act as a precision observable.

Abstract We study the relations between low-energy constants in the chiral Lagrangians with $$\Delta (1232)$$ Δ ( 1232 ) and those in the quark-level description model up to the third chiral order. Ten structure correspondences are involved in getting the relations. This situation is more complicated than the spin-1/2 baryon case. The obtained results may help to further investigations involving the $$\Delta (1232)$$ Δ ( 1232 ) baryons.

The results of ellipse fitting can be considerably distorted by outliers in the fitted point set.To tackle this problem, three improved ellipse fitting algorithms, one of which is based on least trimmed square, and the other two on dual point removal, are proposed.The least trimmed square algorithm starts from a random sample of the original complete fitted set, and then in each iteration, new fitted set is formed by points with the least residual errors, till the process converges to an ellipse fitting a subset whose members are mostly non-outliers.Dual point removal algorithms, on the other hand, starts from the whole fitted set, removes the two points respectively with the maximal positive and the minimal negative residual errors, and halts when the number of points in the remaining set does not exceeds a user-defined threshold.The two proposed algorithms and existing methods are compared on an image base of actual accessories.Experimental results show that when the number of reserved ellipse points is relatively small, the dual removal-based algorithms present the best fitting accuracies, but are slower than the least trimmed square fitting algorithm.When the best performance with parameter tuning is concerned, however, the least trimmed square algorithm achieves a shape-location matching accuracy of 0.62 pixels and an orientation matching accuracy of 0.6°, at an average execution time of 6.5ms, outperforming other algorithms.Other advantages of the proposed algorithms include the small number of algorithm parameters, the intuitiveness of the parameters, and the insensitivity of the algorithm performance to the parameters.These experimental results provide solid evidences for the effectiveness of the proposed algorithms, especially the least trimmed square algorithm.

In this study, AlGaN/GaN Fin-HEMTs with different nanochannel geometric parameters were fabricated and comprehensively characterized. In the arcuate Fin-HEMTs, where the sidewalls arcuate from the source to the drain side, enhancements in the drain current density and transconductance were observed. By extracting and analyzing parameters obtained from small-signal measurements and conducting an analysis of gate capacitance, it was demonstrated that the enhancement can be attributed to the modulation of gate capacitance. This enhances the control capability of the gate over channel carriers, resulting in increased transconductance of the device. Due to the enhanced transconductance, the fT and fmax of the arcuate Fin-HEMTs are both enhanced. Notably, the arcuate Fin-HEMTs achieved a power-added efficiency of 71.4% at a frequency of 3.6 GHz and a drain voltage of 20 V. Meanwhile, the linearity of the arcuate Fin-HEMTs is improved compared with the conventional Fin-HEMTs. [ABSTRACT FROM AUTHOR]