473 research outputs found
correction to at factories
We investigate the correction to the process in the nonrelativistic QCD (NRQCD) factorization
approach. Within some reasonable choices of the relative order- NRQCD
matrix elements, we find that including this new ingredient of correction only
mildly enhances the existing NRQCD predictions. We have also deduced the
asymptotic expressions for the short-distance
coefficients, and reconfirm the early speculation that at next-to-leading order
in , the double logarithm of type appearing in
various NRQCD short-distance coefficients is always associated with the
helicity-suppressed channels.Comment: v3, 6 pages, 2 figures, 1 table; matching the published versio
Some recent progress in understanding exclusive double charmonium production at factories
We review some recent progress in understanding various exclusive double
charmonium production processes at factories, within the nonrelativistic
QCD factorization framework. First we investigate the impact of the joint
perturbative and relativistic correction on the process that has attracted a
great amount of attention in the past decade, . We
then briefly discuss the phenomenological implication of the next-to-leading
order perturbative correction to the processes . We further emphasize a novel theoretical challenge, which is
recently discovered by applying the NRQCD factorization approach to the
helicity-suppressed hard exclusive reactions involving heavy quarkonium.Comment: 9 pages, 2 figures, 1 table. Talk given by Y. J. at the Xth Quark
Confinement and the Hadron Spectrum, 8-12 October 2012, TUM Campus Garching,
Munich, German
Exclusive decay of into
We study the exclusive decay into double charmonium, specifically,
the -wave charmonium plus the -wave charmonium
in the NRQCD factorization framework. Three distinct decay mechanisms, i.e.,
the strong, electromagnetic and radiative decay channels are included and their
interference effects are investigated. The decay processes
are predicted to have the branching
fractions of order , which should be observed in the prospective Super
factory.Comment: 22 pages, 9 figures, 3 table
Cardioprotective effects of the total flavonoids of Polygonum cuspidatum Sieb. et Zucc. Root extract on experimental myocardial infarction in mice
Purpose: To study the cardioprotective effects of the total flavonoids from the roots of Polygonum cuspidatum Sieb. et Zucc. (FHZ) on experimental myocardial infarction in mice.Methods: Ultrasonic-assisted extraction of FHZ was optimized by response surface methodology (RSM) to obtain a higher extraction yield. Myocardial infarction (MI) was established by ligation of the left anterior descending (LAD) branch of the coronary artery in mice. Cardiac troponin T (cTnT), creatine phosphokinase (CPK), lactate dehydrogenase (LDH), lipid peroxide (LPO), malondialdehyde (MDA) and superoxide dismutase (SOD) levels in the serum of mice were assessed by enzyme-linked immunosorbent assay. Furthermore, myocardial infarction size (MIS) was examined by Masson’s Trichrome staining on heart tissues.Results: Optimum extraction conditions of FHZ were as follows: an ethanol concentration of 69.03 %, a liquid-solid ratio of 27.14 g/mL and an extraction time of 30.30 min. The obtained extraction conditions were proven to be accurate and reliable. After treatment with FHZ for 3 and 7 days, the serum level of cTnT in MI mice decreased significantly. Also, the serum levels of CPK, LPO, MDA, and LDH were significantly decreased while SOD level increased in MI mice treated with FHZ. Furthermore, after treatment with FHZ for two weeks, the MIS of MI mice decreased (p < 0.01).Conclusion: RSM is a useful tool to optimize the ultrasonic-assisted extraction conditions for FHZ. Furthermore, FHZ possesses significant cardioprotective effects on experimental myocardial infarction in mice and thus may find application in the clinical management of myocardial infarction.Keywords: Polygonum cuspidatum, Flavonoids, Response surface methodology, Myocardial infarction, Cardioprotectiv
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