Three body radiative decay Bs→ϕKˉ0γB_s\to \phi \bar K^0 \gamma in the PQCD approach

We study the three body radiative decay $B_s\to \phi \bar K^0 \gamma$ by introducing the $\phi K$ pair distribution amplitudes (DAs) in the perturbative QCD approach. This nonperturbative inputs, the two meson DAs, is very important to simplify the calculations. Besides the dominant electromagnetic penguin operator $O_{7\gamma}$, the subleading contributions from chromomagnetic penguin operator $O_{8g}$, quark-loop corrections and annihilation type amplitudes are also considered. We find that the branching ratio for the decay $B_s\to \phi \bar K^0 \gamma$ is about $(9.26^{+1.79+3.12+0.64}_{-1.61-3.86-0.49})\times10^{-8}$, which is much smaller compared with that for the decay $B^0\to \phi K^0\gamma$. It is mainly because that the former decay induces by $b\to d\gamma$ with small CKM matrix element being proportional to $\lambda^3$. The prediction for the direct CP asymmetry is $A^{dir}_{CP}(B_s\to \phi \bar K^0 \gamma)=(-4.1^{+0.4+1.7+0.2}_{-0.6-1.2-0.1})\%$, which is well consistent with the result from the U-spin symmetry approach. we also predict the $B_s \to\phi \bar K^0\gamma$ decay spectrum, which exhibits a maximu at the $\phi K$ invariant masss around 1.95 GeV.Comment: 17 pages,6 figures, Accepted for publication in EPJ

RANCANGAN SISTEM PENGAMATAN PEMBELAJARAN PERCAKAPAN BAHASA MANDARIN TINGKAT MAHIR (高级汉语口语课课堂观察体系设计——以COLT量表为例)

Classroom observation is a way of study on the class in which observers depends on his own feeling or other related auxiliary means to gather and analyze informations about the whole class. It is a comprehensive behavior system which relies on some certain tool, rather than a go-as-you-please observation. This article is absolutly based on COLT: Communicative Orientation of Language Teaching. At first, we need to confirm the target of the study, observation object, the time and the content. And then we designed two parts of the form including Class Activity Form and Communicative orientation of Language Form according to the situation of Advanced Chinese Conversation. Finally, we put foward some matters needing attention about COLT Design

Interpersonal Function of Mood and Modal System in English Commercial Advertisements

This paper studies the mood and modal system and its interpersonal function of language in English commercial advertising on basis of Halliday’s systemic-functional grammar theory. Starting from the examples of English commercial advertisements，this paper analyzes the characteristics of its mood system and modal system respectively, and concludes the three specific interpersonal functions of mood modal system in realizing the purpose of English commercial advertisements

The Influence of Teaching Practice in Primary and Secondary Schools on Teaching Efficacy of Normal University Students

This study was conducted with 51 normal university students in a third-year class of an English major at a university. A combination of quantitative and qualitative analysis was used, and questionnaires and interviews were adopted as research tools. The questionnaire survey was applied to measure the teaching efficacy of the students before and after the internship as a volunteer teacher. Six normal university students majoring in English from the object of study were selected for interviews and recordings, and two interviews were conducted before and after the internship to dig deeper into imperceptible changes in the subjective emotions of those students before and after their internships. After the questionnaires and interviews were completed at each stage, SPSS 26.0 was used to analyse the stage data and overall data from the questionnaires, and content analysis was carried out on the interview data. The aim of this paper is to explore the impact of educational internships on normal university students’ sense of teaching efficacy, identify the influencing factors, propose strategies to enhance the sense of teaching efficacy of normal university students majoring in English, and provide guiding suggestions for the pre-service cultivation of normal university students, the construction of courses for those students, and the improvement of the level of cooperation with internship bases

Study of the K1(1270)−K1(1400)K_1(1270)-K_1(1400) mixing in the decays B→J/ΨK1(1270),J/ΨK1(1400)B\to J/\Psi K_1(1270), J/\Psi K_1(1400)

We studied the B meson decays $B\to J/\Psi K_1(1270,1400)$ in the pQCD approach beyond the leading order. With the vertex corrections and the NLO Wilson coefficients included, the branching ratios of the considered decays are $Br(B^+\to J/\Psi K_1(1270)^+)=1.76^{+0.65}_{-0.69}\times10^{-3}, Br(B^+\to J/\Psi K_1(1400)^+)=7.03^{+2.70}_{-2.52}\times10^{-4}$, and $Br(B^0\to J/\Psi K_1(1270)^0)=(1.63^{+0.60}_{-0.64})\times10^{-3}$ with the mixing angle $\theta_{K_1}=33^\circ$, which can agree well with the data or the present experimental upper limit within errors. So we support the opinion that $\theta_{K_1}\sim33^\circ$ is much more favored than $58^{\circ}$. Furthermore, we also give the predictions for the polarization fractions, direct CP violations from the different polarization components, the relative phase angles for the considered decays with the mixing angle $\theta_{K_1}=33^\circ$ and $58^\circ$, respectively. The direct CP violations of the two charged decays $B^+\to J/\Psi K_1(1270,1400)^+$ are very small $(10^{-4}\sim10^{-5})$, because there is no weak phase until up to $\mathcal{O}(\lambda^4)$ with the Wolfenstein parameter $\lambda=0.22537$. These results can be tested at the running LHCb and forthcoming Super-B experiments.Comment: 14 pages,3 figures,to appear in EPJ