462 research outputs found
S-D mixing and production in annihilation and B decay and its radiative transitions
The large decay rate observed by Belle for , which is
comparable to , might indicate either an unexpectedly
large S-D mixing angle or the leading role of the
color-octet mechanism in D-wave charmonium production in B decay. By
calculating the production rate of in the continuum
annihilation at 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 may dramatically change from 0.04 (for ) to 200 (for ) due to the large S-D
interference effect, thus the E1 transition measurement of 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 charmonium and XYZ states in at BESIII
Within the framework of nonrelativistic quantum chromodynamics, we study the
production of charmonium states in at BESIII
with (n=1, 2, 3, and 4), (n=1, 2, and 3), and
(n=1 and 2). The radiative and relativistic corrections are
calculated to next-to-leading order for and wave states. We then argue
that the search for states such as , , ,
and in at BESIII may help clarify the nature
of these states. BESIII can search states through two body process
, where decay to , , or
. This result may be useful in identifying the nature of
states. For completeness, the production of charmonium in at B factories is also discussed.Comment: Comments and suggestions are welcome. References are update
Understanding the processes observed by Belle
We calculate the production cross sections for ,
and in annihilation through one virtual photon in the
framework of perturbative QCD with constituent quarks. The calculated cross
sections for and production are roughly in agreement
with the recent Belle data. The helicity decomposition for meson
production is also calculated. The fraction of the final
state in process is found to be 65%. The fraction of
production is 100% and is forbidden in annihilation
through one virtual photon. We further consider annihilation through
two virtual photons, and then find the fraction of in process to be about 91%.Comment: 8 pages, 2 figure
Search for excited charmonium states in Annihilation at GeV
We suggest searching for excited charmonium states in annihilation
via double charmonium production at GeV with 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
(n=2,3) and (m=3,4) may have appreciable
potentials to be observed; while for the C=- states, the production
and especially the production might provide opportunities for
observing the 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
<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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