Peak shifts due to B(∗)−Bˉ(∗)B^{(*)}-\bar{B}^{(*)} rescattering in Υ(5S)\Upsilon(5S) dipion transitions

We study the energy distributions of dipion transitions $\Upsilon(5S)$ to $\Upsilon(1S,2S,3S)\pi^+\pi^-$ in the final state rescattering model. Since the $\Upsilon(5S)$ is well above the open bottom thresholds, the dipion transitions are expected to mainly proceed through the real processes $\Upsilon(5S)\to B^{(*)}\bar{B}^{(*)}$ and $B^{(*)}\bar{B}^{(*)}\to \Upsilon(1S,2S,3S)\pi^+\pi^-$. We find that the energy distributions of $\Upsilon(1S,2S,3S)\pi^+\pi^-$ markedly differ from that of $\Upsilon(5S)\to B^{(*)}\bar{B}^{(*)}$. In particular, the resonance peak will be pushed up by about 7-20 MeV for these dipion transitions relative to the main hadronic decay modes. These predictions can be used to test the final state rescattering mechanism in hadronic transitions for heavy quarkonia above the open flavor thresholds.Comment: Version published in PRD, energy dependence of the total width in Eq.(12) restored and corresponding figure changed, more discussion and clarification adde

QCD radiative correction to color-octet J/ψJ/\psi inclusive production at B Factories

In nonrelativistic Quantum Chromodynamics (NRQCD), we study the next-to-leading order (NLO) QCD radiative correction to the color-octet $J/\psi$ inclusive production at B Factories. Compared with the leading-order (LO) result, the NLO QCD corrections are found to enhance the short-distance coefficients in the color-octet $J/\psi$ production $e^+ e^-\to c \bar c (^3P_0^{(8)} {\rm or} ^3P_0^{(8)})g$ by a factor of about 1.9. Moreover, the peak at the endpoint in the $J/\psi$ energy distribution predicted at LO can be smeared by the NLO corrections, but the major color-octet contribution still comes from the large energy region of $J/\psi$. By fitting the latest data of $\sigma(e^{+}e^{-}\to J/\psi+X_{\mathrm{non-c\bar{c}}})$ observed by Belle, we find that the values of color-octet matrix elements are much smaller than expected earlier by using the naive velocity scaling rules or extracted from fitting experimental data with LO calculations. As the most stringent constraint by setting the color-singlet contribution to be zero in $e^{+}e^{-}\to J/\psi+X_{\mathrm{non-c\bar{c}}}$, we get an upper limit of the color-octet matrix element, $+ 4.0 <0| {\cal O}^{J/\psi} [{}^3P_0^{(8)}]|0>/m_c^2 <(2.0 \pm 0.6)\times 10^{-2} {\rm GeV}^3$ at NLO in $\alpha_s$.Comment: 18 pages, 8 figure

Rethinking Measures of Attitude Toward Technology in Technology Education

Technology curriculums encompass an interdisciplinary approach that integrates science, engineering, the arts, and mathematics, along with a design-oriented learning process. Given the rapid advancement of technology and the challenging environment, technology education has the potential to enhance students' positive outlook on technology. The objectives of this study are to gather existing student attitude scales for technology education, analyse the cognitive, affective, behavioural, and environmental components of these scales, and describe the assessment format and its application. This study referenced established research procedures and instructions, used keywords to research and examine the literature, and collected literature on relevant scales. Afterwards, a coding framework was developed based on the theoretical structure of this study for the research content analysis. Last, descriptive data and critical analysis information were reported. The results of this study can offer a comprehensive component structure for the development of attitude scales in technology education. Furthermore, they will contribute to a more comprehensive understanding of how research in technology education investigates students' attitudes

Understanding the e+e−→D(∗)+D(∗)−e^+e^-\to D^{(*)+}D^{(*)-} processes observed by Belle

We calculate the production cross sections for $D^{*+}D^{*-}$, $D^+D^{*-}$ and $D^+D^-$ in $e^+e^-$ annihilation through one virtual photon in the framework of perturbative QCD with constituent quarks. The calculated cross sections for $D^{*+}D^{*-}$ and $D^+D^{*-}$ production are roughly in agreement with the recent Belle data. The helicity decomposition for $D^{*}$ meson production is also calculated. The fraction of the $D^{*\pm}_LD^{*\mp}_T$ final state in $e^+e^-\to D^{*+}D^{*-}$ process is found to be 65%. The fraction of $DD^*_T$ production is 100% and $DD^*_L$ is forbidden in $e^+e^-$ annihilation through one virtual photon. We further consider $e^+e^-$ annihilation through two virtual photons, and then find the fraction of $DD^{*}_T$ in $e^+e^-\to DD^{*}$ process to be about 91%.Comment: 8 pages, 2 figure

Υ\Upsilon radiative decays to light quark jets and color octet mechanism

We study radiative decays of $\Upsilon$ to light quark jets in nonrelativistic QCD by taking both the color singlet and color octet $b\bar b$ operators into consideration. The cut for quark jet energy and cut for the angle between two quark jets are introduced. The sensitivity to the soft and collinear singularities in the loop integrals are greatly reduced by these cuts. With the jet energy cut of about 1 GeV, and the jet angle cut of about $36^\circ$, the branching ratio for $\Upsilon\to\gamma q\bar q$ is found to be $8.2\times 10^{-4}$ from color singlet contributions. The color octet contributions could be much larger than that of color singlet, depending on the estimate of the color octet matrix elements. This process may provide a new test for the color octet mechanism in nonrelativistic QCD.Comment: journal version; a few references adde

Υ(4S,5S)→Υ(1S)η\Upsilon(4S,5S)\to\Upsilon(1S)\eta transitions in the rescattering model and the new BaBar measurement

The $\eta$ transitions of $\Upsilon(4S,5S)$ into $\Upsilon(1S,2S)$ are studied in the rescattering model by considering the final state interactions above the $B\bar B$ threshold. The width of the $\eta$ transition of $\Upsilon(4S)$ into $\Upsilon(1S)$ is found to be larger than that of the dipion transition, and the ratio of $\Gamma(\Upsilon(4S)\to\Upsilon(1S)\eta)$ to $\Gamma(\Upsilon(4S)\to\Upsilon(1S)\pi^+\pi^-)$ is predicted to be $R_4=1.8{-}4.5$, which is about two orders of magnitude larger than the expectation of the conventional hadronic transition theory, and is supported by the new BaBar measurement. The widths of the $\eta$ transitions of $\Upsilon(5S)$ are found to be sensitive to the coupling constants $g_{\Upsilon(5S)B^{(*)}B^{(*)}}$ due to a large cancelation between contributions from the $B\bar{B}$, $B^*\bar{B}+c.c.$, and $B^*\bar{B}^*$ channels, and only a rough estimate $\Gamma(\Upsilon(5S)\to\Upsilon(1S,2S)\eta)=10{-}200$ KeV can be given. The widths of the $\eta'$ transitions of $\Upsilon(4S,5S)$ are also discussed, and they could be much smaller than that of the corresponding $\eta$ transitions mainly due to the tiny phase space.Comment: Version published in PRD, 5 pages, 1 figur