79 research outputs found
Investigating the excited states through and decay channels
Inspired by the five newly observed states by the LHCb
detector, we study the states as the wave molecular
pentaquarks with , , , and
by solving the RGM equation in the framework of chiral quark
model. Both the energies and the decay widths are obtained in this work. Our
results suggest that can be explained as an wave
resonance state of with , and the decay channels
are the wave and . Other reported
states cannot be obtained in our present calculation. Another
state with much higher mass 3533 MeV with
is also obtained. In addition, the calculation is
extended to the states, similar results as that of
are obtained.Comment: 6 pages, 2 figure
Possible -like dibaryon states with heavy quarks
Possible -like dibaryon states and
are investigated within the framework of quark
delocalization color screening model. The results show that the interaction
between two 's is repulsive, so it cannot be bound state by
itself. However, the strong attraction in and
channels and the strong channel coupling, due to
the central interaction of one-gluon-exchange and one-pion-exchange, among
, and
push the energy of system below the threshold of
by MeV. The corresponding system
has the similar properties as that of
system, and a bound state is also possible in
system.Comment: 6 pages, 4 figures, 3 table
Interpreting and as charged tetraquark states
In the framework of color flux-tube model with a four-body confinement
potential, the lowest charged tetraquark states
are studied by using the variational
method, Gaussian expansion method. The results indicate that some compact
resonance states can be formed, the states can not decay into two color singlet
mesons and through the breakdown and recombination of
color flux tubes but into and . The four-body
confinement potential is an crucial dynamical mechanism for the formation of
states, The decay mechanism is similar to that of compound nucleus and
therefore the states should be called "color confined, multi-quark resonance"
states. The newly observed charged states and
can be accommodated in the color flux-tube model and can be interpreted as the
-wave tetraquark states with quantum numbers
and and 2, respectively.Comment: 8 pages, no figur
Theoretical study of a resonance in partial wave of nucleon-nucleon scattering
Inspired by the recent results of the WASA-at-COSY Collaboration, in which
they found a resonance pole in the coupled - partial
waves as expected from the resonance hypothesis, we calculated the
resonance structure in the coupled - partial wave phase
shifts of nucleon-nucleon scattering in the framework of two constituent quark
models: the quark delocalization color screening model and the chiral quark
model. Our results show that there is a resonance in
the coupled and partial waves in both of
these two models, which is in accordance with the expectation from the
resonance structure. The resonance shape in the partial wave
is remarkable, whereas in the phase shifts there is a small
rise around the resonance energy. This result is in agreement with the recent
experimental observations of WASA-at-COSY Collaboration.Comment: 5 pages, 3 figure
Further study of the dibaryon within constituent quark models
Inspired by the discovery of the dibaryon and the experimental search
of dibaryon with the STAR data, we study the strange dibaryon
further in the framework of quark delocalization color screening
model and chiral quark model. We have shown is a narrow resonance in
D-wave scattering before. However, the - scattering
data analysis is quite complicated. Here we calculate the low-energy
scattering phase shifts, scattering length, effective range and binding energy
to provide another approach of STAR data analysis. Our results show there
exists an "bound" state, which can be observed by the -
correlation analysis with RHIC and LHC data, or by the new developed automatic
scanning system at J-PARC. Besides, we also find that the hidden color
channel-coupling is important for the system to develop
intermediate-range attraction.Comment: 7 pages, 2 figure
The effect of hidden color channels on Nucleon-Nucleon interaction
This letter reports the nucleon-nucleon() interaction obtained from
multi-channel, including hidden color channels, coupling quark model
calculation. The results show that the hidden color channels coupling provides
the intermediate range attraction which is usually assumed to be due to
multi- or meson exchange and that the short and intermediate
range interaction can be described solely by the fundamental quark-gluon
degree of freedom of QCD.Comment: 5 pages, 5 figure
Possible existence of a dibaryon candidate ()
Inspired by the experimental report by WASA-at-COSY Collaboration, we
investigate the possibile existence of the dibaryon candidate with
quantum numbers (). The dynamical calculation shows that we
cannot obtain the bound state in the models which can obtain the
experimental . %although the state can bound in the range of
parameters in quark models. The low-energy scattering phase shifts of the
scattering give the same conclusion. Besides, the mass calculation
by using the Gursey-Radicati mass formula and the analysis of the matrix
elements of the color magnetic interaction show that the mass of is
larger than that of ( with ), which indicate that
it is less possible for the than the to form bound state.Comment: 8 pages, 3 figure
Multi-quark states
The pentaquark state recently discovered has been discussed based on various
quark model calculations. Odd parity for the state can not be ruled out
theoretically because contributions related to non-trivial color structures
have not been studied completely. Other multiquark states, especially
dibaryons, have been discussed also. A strangeness -3 N dibaryon has
been shown to have a width as small as 12-22 keV and should be detectable in
high productivity reactions such as at RHIC, COMPAS and the planned
JHF and FAIR projects.Comment: 13 pages, no figur
X(1835), X(2120) and X(2370) in a flux tube model
Nonstrange baryonium spectrum is systematically studied by using the Gaussian
expansion method in a flux tube model with the six-body confinement potential.
All the model parameters are fixed by baryon properties, so the baryonium
calculation is parameter-free. We find that X(1835) and X(2370), which are
observed in the radiative decay of by BES collaboration, can be
described as and bound states with
quantum numbers , respectively, such bound states should
be color confinement resonances with three-dimensional configurations similar
to dumbbell, however, X(2120) can not be accommodated in our model.Comment: 6 pages, 1 figure. arXiv admin note: text overlap with
arXiv:1201.176
Configuration mixing and effective baryon-baryon interactions
The effective baryon-baryon interactions is studied in the refined quark
delocalization color screening model (QDCSM), in which the different quark
clusterings are fully taken into account, instead of controlling by a
variational delocalization parameter between two 3-quark
clusters. The symmetry bases are employed to do the calculation, all possible
configurations for two quark clusters are considered. The results obtained are
very similar to that of QDCSM. It is inferred that the delocalization parameter
used in QDCSM is an economic and effective way to describe the
mixing of quarks between baryons.Comment: 5 pages, 5 figures, 5 table
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