34,776 research outputs found
Molecular states with hidden charm and strange in QCD Sum Rules
This work uses the QCD Sum Rules to study the masses of the
and molecular states with quantum numbers . Interpolating currents with definite C-parity are employed, and the
contributions up to dimension eight in the Operator Product Expansion (OPE) are
taken into account. The results indicate that two hidden strange
charmonium-like states may exist in the energy ranges of GeV
and GeV, respectively. The hidden strange charmonium-like
states predicted in this work may be accessible in future experiments, e.g.
BESIII, BelleII and SuperB. Possible decay modes, which may be useful in
further research, are predicted.Comment: 15 pages, 6 figures, 2 tables, to appear in EP
Estimating the mass of the hidden charm tetraquark state via QCD sum rules
By using QCD sum rules, the mass of the hidden charm tetraquark
state with (HCTV) is
estimated, which presumably will turn out to be the newly observed
charmonium-like resonance . In the calculation, contributions up
to dimension eight in the operator product expansion(OPE) are taken into
account. We find , which is
consistent, within the errors, with the experimental observation of
. Extending to the b-quark sector, is obtained. The calculational result
strongly supports the tetraquark picture for the "exotic" states of
and .Comment: 13 pages,3 figures, 1 table, version to appear in EPJ
Mass Spectra of , , and Exotic Glueballs
With appropriate interpolating currents the mass spectra of ,
, and oddballs are studied in the framework of QCD sum rules
(QCDSR). We find there exits one stable oddball with mass of , and one stable oddball with mass of , whereas, no stable oddball shows up. The possible
production and decay modes of these glueballs with unconventional quantum
numbers are analyzed, which are hopefully measurable in either BELLEII, PANDA,
Super-B or LHCb experiments.Comment: 10 pages, 12 figures, 4 tables, to appear in NPB. arXiv admin note:
substantial text overlap with arXiv:1408.399
Interpretation of as the Hidden Charm Tetraquark States via QCD Sum Rules
By using QCD Sum Rules, we found that the charged hidden charm tetraquark states with and , which are possible
quantum numbers of the newly observed charmonium-like resonance ,
have masses of and . The contributions up to dimension eight in the
Operator Product Expansion (OPE) were taken into account in the calculation.
The tetraquark mass of state was consistent with the
experimental data of , suggesting the state possessing
the quantum number of . Extending to the b-quark sector, the
corresponding tetraquark masses
and were obtained, which are
testable in future B-factories.Comment: 15 pages, 6 figures, to appear in European Physical Journal
Measuring dynamic oil film coefficients of sliding bearing
A method is presented for determining the dynamic coefficients of bearing oil film. By varying the support stiffness and damping, eight dynamic coefficients of the bearing were determined. Simple and easy to apply, the method can be used in solving practical machine problems
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