Exotic QQqˉqˉQQ\bar{q}\bar{q}, QQqˉsˉQQ\bar{q}\bar{s} and QQsˉsˉQQ\bar{s}\bar{s} states

After constructing the possible $J^P=0^-, 0^+, 1^-$ and $1^+$ $QQ\bar{q}\bar{q}$ tetraquark interpolating currents in a systematic way, we investigate the two-point correlation functions and extract the corresponding masses with the QCD sum rule approach. We study the $QQ\bar{q}\bar{q}$, $QQ\bar{q}\bar{s}$ and $QQ\bar{s}\bar{s}$ systems with various isospins $I=0, 1/2, 1$. Our numerical analysis indicates that the masses of doubly-bottomed tetraquark states are below the threshold of the two bottom mesons, two bottom baryons and one doubly bottomed baryon plus one anti-nucleon. Very probably these doubly-bottomed tetraquark states are stable.Comment: 37 pages, 2 figure

Possible JPC=0+−J^{PC} = 0^{+-} Exotic State

We study the possible exotic states with $J^{PC} = 0^{+-}$ using the tetraquark interpolating currents with the QCD sum rule approach. The extracted masses are around 4.85 GeV for the charmonium-like states and 11.25 GeV for the bottomomium-like states. There is no working region for the light tetraquark currents, which implies the light $0^{+-}$ state may not exist below 2 GeV.Comment: 13 pages, 11 figures, 2 table

SLA as an interdiscipline: A bibliometric study

Nowadays, research in second language acquisition (SLA) is becoming increasingly interdisciplinary while many technical frontiers and research hotspots have emerged. Many studies focus on interdisciplinary topics, but few in-depth studies have been conducted on interdisciplinarity. This study examined the interdisciplinarity of SLA and the interdisciplinary development process using a bibliometrics approach. The study has found that the SLA discipline has played roles as both the provider and recipient of knowledge in the development of interdisciplines. In the first case, SLA theories and methods flow into the research areas of life sciences and technology to form interdisciplinary studies with brain research, neurology, cognition, computer technology, and engineering, making SLA a provider of knowledge In the second case, SLA research receives knowledge from areas of arts and humanities and social sciences as well as from interdisciplinary studies within its own discipline, making SLA a receiver of knowledge. The new insights into the interdisciplinarity of SLA provided in this study are helpful for our deeper understanding of the interdisciplinary nature of the SLA discipline

D∗Dˉ∗D^*\bar D^* molecule interpretation of Zc(4025)Z_c(4025)

We have used QCD sum rules to study the newly observed charged state $Z_c(4025)$ as a hidden-charm $D^*\bar D^*$ molecular state with the quantum numbers $I^G(J^{P})=1^+(1^{+})$. Using a $D^*\bar D^*$ molecular interpolating current, we have calculated the two-point correlation function and the spectral density up to dimension eight at leading order in $\alpha_s$. The extracted mass is $m_X=(4.04\pm0.24)$ GeV. This result is compatible with the observed mass of $Z_c(4025)$ within the errors, which implies a possible molecule interpretation of this new resonance. We also predict the mass of the corresponding hidden-bottom $B^*\bar B^*$ molecular state: $m_{Z_b}=(9.98\pm0.21)$ GeV.Comment: 6 pages, 5 figures. Version appears in Eur. Phys. J.

Price Stabilization in the Taiwan Hog and Broiler Industries: Evidence from a STAR Approach

The paper examines the effectiveness of the price stabilization mechanism for the broiler and poultry industry in Taiwan during the period 1999 to 2008. After presenting some background information on the domestic marketing system and price stabilization mechanisms for the broiler and pork industry in Taiwan, the paper discusses the smooth transition autoregressive (STAR) methodology. Monthly hog and broiler price data from 1999 to 2008 at farm, import and retail levels are analyzed using the nonlinear, non-asymmetric logistic STAR model in order to determine price transmission structure. A price threshold parameter is used so that price transmission levels can vary, thereby allowing an examination of the efficacy with which the hog and broiler price stabilization mechanisms take effect.Broiler industry, Pork industry, Price stabilization, Domestic marketing system, Smooth transition autoregressive (STAR) methodology

The Choice of Tense in Translation into the Second Language

English tense is widely believed as one of the most problematic areas in the “interlanguage”, which includes non-native English speakers’ English writing and translations into the translator’s second language. This study aims to investigate the relationships between the tense choice in translation, the tense in the Chinese source text, and the translation competence of translators. A small Chinese-English parallel corpus has been built with 127 translations of Chinese press editorials by experienced native English speaking translators, experienced native Chinese speaking translators, and novice native Chinese speaking translators. Cross-tabulate analyses of this study have shown that the three groups of translators differ from one another significantly in their handling of marked Chinese past tense verbs, while they do not when translating Chinese sentences with contextually marked tense. This study suggests that in order to improve their translation quality, (1) experienced native Chinese speaking translators need to increase the percentages of Present Simple, Present Progress, Present Perfect, and Past Simple, and reduce the percentages of Past Perfect in their translation; (2) novice native Chinese speaking translators need to increase the percentages of Present Simple, and Present Progress, and reduce the percentages of Past Perfect, Past Simple, and Present Perfect in their translation