Feynman Rules in the Type III Natural Flavour-Conserving Two-Higgs Doublet Model

We consider a two Higgs-doublet model with $S_3$ symmetry, which implies a $\pi \over 2$ rather than 0 relative phase between the vacuum expectation values $$and$$. The corresponding Feynman rules are derived accordingly and the transformation of the Higgs fields from the weak to the mass eigenstates includes not only an angle rotation but also a phase transformation. In this model, both doublets couple to the same type of fermions and the flavour-changing neutral currents are naturally suppressed. We also demonstrate that the Type III natural flavour-conserving model is valid at tree-level even when an explicit $S_3$ symmetry breaking perturbation is introduced to get a reasonable CKM matrix. In the special case $\beta = \alpha$, as the ratio $\tan\beta = {v_2 \over v_1}$ runs from 0 to $\infty$, the dominant Yukawa coupling will change from the first two generations to the third generation. In the Feynman rules, we also find that the charged Higgs currents are explicitly left-right asymmetric. The ratios between the left- and right-handed currents for the quarks in the same generations are estimated.Comment: 16 pages (figures not included), NCKU-HEP/93-1

Synthesis and pinning properties of the infinite-layer superconductor Sr0.9La0.1CuO

We report the high-pressure synthesis of the electron-doped infinite-layer superconductor Sr0.9La0.1CuO2 and its superconducting properties. A Rietveld analysis of X-ray powder diffraction data showed that, within the resolution of the measurement, the sample had purely an infinite-layer structure without any discernible impurities. The superconducting volume fraction and the transition width were greatly improved compared to those in previous reports. The irreversibility field line and the intragranular critical current density were much higher than those of La1.85Sr0.15CuO4 and Nd1.85Ce0.15CuO4. The stronger pinning behaviors are consistent with the strong interlayer coupling due to the short distance between CuO2 planes.Comment: Physica C (in press) 5 pages, 4 figur

Faktor-faktor yang mempengaruhi remaja Lembah Klang untuk terus membaca dan membeli melalui pengiklanan Facebook

Facebook bukan sahaja menghubungkan individu atau komuniti, malah ia juga bertindak sebagai laman penting bagi industri pengiklanan untuk menjalankan urusan perniagaan secara global. Kajian ini melihat sejauhmanakah faktor-faktor kepuasan keperluan kognitif, kepuasan keperluan afektif, kepuasan keperluan peribadi integratif serta kepuasan keperluan sosial integratif mempengaruhi tahap penerimaan remaja yang berada pada lingkungan umur 18-24 tahun terhadap pengiklanan dalam Facebook. Model kajian dibentuk berdasarkan Teori Kegunaan dan Kepuasan oleh Elihu Katz, Michael Gurevitch & Jay G. Blumler (1973). Seramai 200 responden dipilih secara Purposive Sampling di sekitar Lembah Klang. Data dikumpulkan menerusi kaedah tinjauan menggunakan soal selidik. Hasil kajian ini menunjukkan pembelian produk untuk memenuhi tuntutan ego sendiri merupakan faktor kepuasan keperluan kognitif yang dapat mempengaruhi tahap penerimaan remaja terhadap pengiklanan Facebook. Selain itu, bagi aspek kepuasan keperluan afektif pula menunjukkan bahawa hanya ciri-ciri keistimewaan iaitu pelbagai aplikasi Facebook yang digunakan dalam pengiklanan Facebook dapat mempengaruhi tahap penerimaan remaja terhadap pengiklanan dalam Facebook. Bagi faktor kepuasan keperluan peribadi integratif pula iaitu ciri pengguna dan sikap berhati-hati terhadap perubahan didapati mempunyai hubungan secara langsung dengan tahap penerimaan pengiklanan Facebook. Dari segi sikap kepuasan keperluan sosial integratif, majoriti responden dalam kajian ini didapati adalah bersikap kolektivisme di mana ia dibuktikan mempengaruhi tahap penerimaan golongan remaja terhadap pengiklanan Facebook

The academic and social adjustment problems of Taiwan-Chinese students studying at Iowa regents higher educational institutions

Cross-cultural contacts are easier and more convenient because technological developments have shortened the distance between countries. The third world countries demand advanced technological and industrialized knowledge and skills to develop their countries. Therefore, they send a large number of students to highly developed countries to absorb their invaluable scientific experiences. In particular, the third world countries send a large number of students to the United States because of its leading position in technology, advanced economic development and democratic leadership

Effects of a Cooperative Learning Strategy on the Effectiveness of Physical Fitness Teaching and Constraining Factors

The effects of cooperative learning and traditional learning on the effectiveness and constraining factors of physical fitness teaching under various teaching conditions were studied. Sixty female students in Grades 7–8 were sampled to evaluate their learning of health and physical education (PE) according to the curriculum for Grades 1–9 in Taiwan. The data were quantitatively and qualitatively collected and analyzed. The overall physical fitness of the cooperative learning group exhibited substantial progress between the pretest and posttest, in which the differences in the sit-and-reach and bent-knee sit-up exercises achieved statistical significance. The performance of the cooperative learning group in the bent-knee sit-up and 800 m running exercises far exceeded that of the traditional learning group. Our qualitative data indicated that the number of people grouped before a cooperative learning session, effective administrative support, comprehensive teaching preparation, media reinforcement, constant feedback and introspection regarding cooperative learning strategies, and heterogeneous grouping are constraining factors for teaching PE by using cooperative learning strategies. Cooperative learning is considered an effective route for attaining physical fitness among students. PE teachers should consider providing extrinsic motivation for developing learning effectiveness

Decay of Correlations in a Topological Glass

In this paper we continue the study of a topological glassy system. The state space of the model is given by all triangulations of a sphere with $N$ nodes, half of which are red and half are blue. Red nodes want to have 5 neighbors while blue ones want 7. Energies of nodes with other numbers of neighbors are supposed to be positive. The dynamics is that of flipping the diagonal between two adjacent triangles, with a temperature dependent probability. We consider the system at very low temperatures. We concentrate on several new aspects of this model: Starting from a detailed description of the stationary state, we conclude that pairs of defects (nodes with the "wrong" degree) move with very high mobility along 1-dimensional paths. As they wander around, they encounter single defects, which they then move "sideways" with a geometrically defined probability. This induces a diffusive motion of the single defects. If they meet, they annihilate, lowering the energy of the system. We both estimate the decay of energy to equilibrium, as well as the correlations. In particular, we find a decay like $t^{-0.4}$

Three-Dimensional Superconductivity in the Infinite-Layer Compound Sr_{0.9}La_{0.1}CuO_2 in Entire Region below TcT_c

The infinite-layer compound ACuO$_{2}$ (A $=$ alkaline-earth ions) is regarded as the most suitable material for exploring the fundamental nature of the CuO$_2$ plane because it does not contain a charge-reservoir block, such as a rock-salt or a fluorite like block. We report that superconductivity in the infinite-layer compound Sr$_{0.9}$La$_{0.1}$CuO$_2$ is of a three-dimensional nature, in contrast to the quasi two-dimensional superconducting behavior of all other cuprates. The key observation is that the $c$-axis coherence length is longer than the $c$-axis lattice constant even at zero temperature. This means that the superconducting order parameter of one CuO$_{2}$ plane overlaps with those of neighboring CuO$_{2}$ planes all the temperatures below the $T_c$. Among all cuprates, only the infinite-layer superconductor shows such a feature.Comment: 4 pages and 4 figure