462 research outputs found

    S-D mixing and ψ(3770)\psi(3770) production in e+ee^+e^- annihilation and B decay and its radiative transitions

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    The large decay rate observed by Belle for B+ψ(3770)K+B^+\to\psi(3770)K^+, which is comparable to B+ψ(3686)K+B^+\to\psi(3686)K^+, might indicate either an unexpectedly large S-D mixing angle θ40o|\theta|\approx 40^o or the leading role of the color-octet mechanism in D-wave charmonium production in B decay. By calculating the production rate of ψ(3770)\psi(3770) in the continuum e+ee^+e^- annihilation at s=10.6\sqrt{s}=10.6 GeV with these two possible approaches (i.e. the large S-D mixing and the color-octet mechanism), we show that the measurement for this process at Belle and BaBar may provide a clear cut clarification for the two approaches. In addition, the radiative E1 transition ratio Γ(ψ(3770)γχc2)/Γ(ψ(3770)γχc1)\Gamma(\psi(3770)\to \gamma\chi_{c2})/\Gamma(\psi(3770)\to \gamma\chi_{c1}) may dramatically change from \sim 0.04 (for θ0o\theta\approx 0^o) to \sim 200 (for θ40o\theta\approx -40^o) due to the large S-D interference effect, thus the E1 transition measurement of ψ(3770)\psi(3770) at BES and CLEO-c will also be very useful in clarifying this issue.Comment: final version to appear in Phys.Rev.D, discussion on uncertainties associated with the color-octet matrix elements is added, 16 pages, 2 figure

    Search for C=+C=+ charmonium and XYZ states in e+eγ+He^+e^-\to \gamma+ H at BESIII

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    Within the framework of nonrelativistic quantum chromodynamics, we study the production of C=+C=+ charmonium states HH in e+eγ + He^+e^-\to \gamma~+~H at BESIII with H=ηc(nS)H=\eta_c(nS) (n=1, 2, 3, and 4), χcJ(nP)\chi_{cJ}(nP) (n=1, 2, and 3), and 1D2(nD)^1D_2(nD) (n=1 and 2). The radiative and relativistic corrections are calculated to next-to-leading order for SS and PP wave states. We then argue that the search for C=+C=+ XYZXYZ states such as X(3872)X(3872), X(3940)X(3940), X(4160)X(4160), and X(4350)X(4350) in e+eγ + He^+e^-\to \gamma~+~H at BESIII may help clarify the nature of these states. BESIII can search XYZXYZ states through two body process e+eγHe^+e^-\to \gamma H, where HH decay to J/ψπ+πJ/\psi \pi^+\pi^-, J/ψϕJ/\psi \phi, or DDˉD \bar D. This result may be useful in identifying the nature of C=+C=+ XYZXYZ states. For completeness, the production of C=+C=+ charmonium in e+eγ+ He^+e^-\to \gamma +~H at B factories is also discussed.Comment: Comments and suggestions are welcome. References are update

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

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

    Search for excited charmonium states in e+ee^+e^- Annihilation at s=10.6\sqrt{s}=10.6 GeV

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    We suggest searching for excited charmonium states in e+ee^+e^- annihilation via double charmonium production at s=10.6\sqrt{s}=10.6 GeV with BB factories, based on a more complete leading order calculation including both QCD and QED contributions for various processes. In particular, for the C=+ states, the χc0(nP)\chi_{c0}(nP) (n=2,3) and ηc(mS)\eta_c(mS) (m=3,4) may have appreciable potentials to be observed; while for the C=- states, the ηchc\eta_ch_c production and especially the χc1hc\chi_{c1}h_c production might provide opportunities for observing the hch_c with higher statistics in the future. A brief discussion for the X(3940) observed in the double charmonium production is included.Comment: 13 pages and 8 figures in PRD version; QED contribution added; experimental and theoretical developments since 2004 summarized; references adde

    Overexpression of members of the microRNA-183 family is a risk factor for lung cancer: A case control study

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    <p>Abstract</p> <p>Background</p> <p>Lung cancer is the leading cause of cancer-related deaths worldwide. Early detection is considered critical for lung cancer treatment. MicroRNAs (miRNAs) have shown promise as diagnostic and prognostic indicators. This study was to identify specific miRNAs with diagnostic and prognostic value for patients with lung cancer, and to explore the correlation between expression profiles of miRNAs and patient survival.</p> <p>Methods</p> <p>Gene expression of members of the miR-183 family (miR-96, miR-182, and miR-183) were examined in 70 paired samples from lung cancer patients (primary cancer and non-cancerous tissues and sera), as well as 44 serum samples from normal volunteers and lung cancer cell lines by quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR). The correlation between the expression of miRNAs in tissues, sera, and patient overall survival were also examined by log-rank and Cox regression analysis.</p> <p>Results</p> <p>Expression levels of members of the miR-183 family in lung cancer tumor and sera were higher than that of their normal counterparts. The miR-96 expression in tumors was positively associated with its expression in sera. Log-rank and Cox regression analyses demonstrated that high expression of tumor and serum miRNAs of the miR-183 family were associated with overall poor survival in patients with lung cancer.</p> <p>Conclusions</p> <p>Our results suggest that the expressions of miR-96, miR-182, and miR-183 in tumor and sera may be considered potential novel biomarkers for the diagnosis and prognosis of lung cancer.</p
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