5,506 research outputs found
Light vector meson and heavy baryon strong interaction
We calculate the coupling constants between the light vector mesons and heavy
baryons within the framework of the light-cone QCD sum rule in the leading
order of heavy quark effective theory. Most resulting sum rules are stable with
the variations of the Borel parameter and the continuum threshold. The
extracted couplings will be useful in the study of the possible heavy baryon
molecular states
Flat Currents of the Green-Schwarz Superstrings in AdS_5 x S^1 and AdS_3 x S^3 backgrounds
We construct a one-parameter family of flat currents in AdS_5 x S^1 and AdS_3
x S^3 Green-Schwarz superstrings, which would naturally lead to a hierarchy of
classical conserved nonlocal charges. In the former case we rewrite the AdS_5 x
S^1 string using a new Z_4-graded base of the superalgebra su(2,2|2). In both
cases the existence of the Z_4 grading in the superalgebras plays a key role in
the construction. As a result, we find that the flat currents, when formally
written in terms of the G_0-gauge invariant lowercase 1-forms, take the same
form as the one in AdS_5 x S^5 case.Comment: 18 pages, LaTeX file. References added and typos correcte
The Decay Properties of the 1^{-+} Hybrid State
Within the framework of the QCD sum rules, we consider the three-point
correlation function, work at the limit q^2 -> 0 and m_\pi -> 0, and pick out
the singular term ~ {1\over q^2} to extract the pionic coupling constants of
the 1^{-+} hybrid meson. Then we calculate the decay widths of different modes.
The decay width of the S-wave modes b_1 \pi, f_1\pi increases quickly as the
hybrid meson mass and decay momentum increase. But for the low mass hybrid
meson around 1.6 GeV, the P-wave decay mode \rho \pi is very important and its
width is around 180 MeV, while the widths of \eta \pi and \eta^\prime \pi are
strongly suppressed. We suggest the experimental search of \pi_1(1600) through
the decay chains at BESIII: e^+e^- -> J/\psi(\psi') -> \pi_1 +\gamma or e^+e^-
-> J/\psi(\psi') -> \pi_1 +\rho where the \pi_1 state can be reconstructed
through the decay modes \pi_1 -> \rho\pi -> \pi^+\pi^-\pi^0 or \pi_1 ->
f_1(1285)\pi^0. It is also interesting to look for \pi_1 using the available
BELLE/BABAR data through the process e^+e^- -> \gamma^\ast -> \rho\pi_1,
b_1\pi_1, \gamma \pi_1 etc.Comment: one reference correcte
The Strong Decay Patterns of the Exotic Hybrid Mesons
We calculate the coupling constants of the decay modes
within the framework of the light-cone QCD sum rule. Then we calculate the
partial width of these decay channels, which differ greatly from the existing
calculations using phenomenological models. For the isovector state,
the dominant decay modes are . For its isoscalar partner, its
dominant decay mode is . We also discuss the possible search of the
state at BESIII, for example through the decay chains or where can
be reconstructed through the decay modes
or . Hopefully the present work will be helpful to the
experimental establishment of the hybrid meson.Comment: 14 pages, 10 figure
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