1,721,100 research outputs found
Possible BK-bar molecular structure of B*s(0)(5725) in the Bethe-Salpeter approach
Full text linkWe interpret the scalar Bs0*(5725) as an S-wave BK̅ molecular bound state in the Bethe-Salpeter approach. In the ladder and instantaneous approximation, with the kernel induced by ρ and ω exchanges, we establish the Bethe-Salpeter equation for Bs0*(5725). We find that the bound state of BK̅ can exist. We also calculate the isospin-violating decay width of the process Bs0*(5725)→Bsπ0 through exchanging K* and B* mesons including the η-π0 mixing effect. We hope that the obtained decay width is instructive for the forthcoming experiment.Guan-Qiu Feng, Zhen-Xing Xie, and Xin-Heng Gu
Cabibbo-suppressed non-leptonic decays of Lambda c and final state interaction
No full textWith the diquark structure of Λc, we investigate the branching ratio of Λc→nπ+ and pπ0. The results show that without considering the final state interaction (FSI), the branching ratio of Λc→pπ0 is only of order 10-6 whereas this ratio could reach 10-4 and is at the same order as Λc→nπ+ if taking into account the FSI effects. Concrete values depend on phenomenological parameters adopted in the calculations. These branching ratios can be measured in the experiments to come.Chen, Shao-Long; Guo, Xin-Heng, Li, Xue-Qian and Wang, Guo-Lihttp://ctp.itp.ac.cn/qikan/Epaper/zhaiyao.asp?bsid=108
Possible explanation why tauB+/-~ tauB(0) but tauD+/-~2tauD(0)
No full textData show that τB±∼τB0, but τD±∼2τD0. The naive interpretation which attributes τD±∼2τD0 to a destructive interference between two quark diagrams for D± decays definitely fails in the B case. We investigate the suggestion of Close and Lipkin that the phases for producing radially excited states ψ2s in the decay products of B mesons can possess an opposite sign to the integrals for ψ1s decay products. Their contributions can partially compensate each other to result in τB±∼τB0. Since D mesons are much lighter than B mesons, such possibilities do not exist in D decays.Dong, Hui-shi Guo, Xin-heng ; Li, Xue-qian ; Zhang, Ru
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Direct CP violation in B -> rho(0)(omega)pi and B -> rho(0)(omega)Kappa
No full textOlivier Leitner, Xin-Heng Guo, A.W. Thomashttp://www.lip.pt/events/2005/hep2005
Non-spectator diquark effects on lifetimes of Lb, Wb(*) and weak decay rates of Sb(*), Xb(*)
No full textWu-Sheng Dai, Xin-Heng Guo, Xue-Qian Li, Gang Zha
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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