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Jialun Ping

Publications and source records attributed to Jialun Ping.

At least 127 records · Page 7Linked to original sources
arXiv2017

Light-meson masses in an unquenched quark model

We perform a coupled-channels calculation of the masses of light mesons with the quantum numbers $IJ^{P=-}$, $(I,J)=0,1$, by including $q\bar{q}$ and $(q\bar{q})^2$ components in a nonrelativistic chiral quark model. The coupling between two- and four-quark configurations is realized through a $^3P_0$ quark-pair creation model. With the usual form of this operator, the mass shifts are large and negative, an outcome which raises serious issues of validity for the quenched quark model. Herein, therefore, we introduce some improvements of the $^3P_0$ operator in order to reduce the size of the mass shifts. By introducing two simple factors, physically well motivated, the coupling between $q\bar{q}$ and $(q\bar{q})^2$ components is weakened, producing mass shifts that are around 10-20% of hadron bare masses.

nucl-th↗
arXiv2017

The structure of pentaquarks $Ω_c^0$ in the chiral quark model

Recently, the experimental results of LHCb Collaboration suggested the existence of five new excited states of $Ω_c^0$, $Ω_c(3000)^0$, $Ω_c(3050)^0$, $Ω_c(3066)^0$, $Ω_c(3090)^0$ and $Ω_c(3119)^0$, the quantum numbers of these new particles are not determined now. To understand the nature of the states, a dynamical calculation of 5-quark systems with quantum numbers $IJ^P=0(\frac{1}{2})^-$, $0(\frac{3}{2})^-$ and $0(\frac{5}{2})^-$ is performed in the framework of chiral quark model with the help of gaussian expansion method. The results show the $Ξ-\bar{D}$, $Ξ_c\bar{K}$ and $Ξ_c^*\bar{K}$ are possible the candidates of these new particles. The distances between quark pairs suggest that the nature of pentaquark states.

hep-ph↗
arXiv2017

Investigating the excited $Ω^{0}_{c}$ states through $Ξ_{c}K$ and $Ξ^{'}_{c}K$ decay channels

Inspired by the five newly observed $Ω^{0}_{c}$ states by the LHCb detector, we study the $Ω_{c}^{0}$ states as the $S-$wave molecular pentaquarks with $I=0$, $J^{P}=\frac{1}{2}^{-}$, $\frac{3}{2}^{-}$, and $\frac{5}{2}^{-}$ 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 $Ω_{c}(3119)^{0}$ can be explained as an $S-$wave resonance state of $ΞD$ with $J^{P}=\frac{1}{2}^{-}$, and the decay channels are the $S-$wave $Ξ_{c} K$ and $Ξ^{'}_{c}K$ . Other reported $Ω^{0}_{c}$ states cannot be obtained in our present calculation. Another $Ω_{c}^{0}$ state with much higher mass 3533 MeV with $J^{P}=\frac{5}{2}^{-}$ is also obtained. In addition, the calculation is extended to the $Ω_{b}^{0}$ states, similar results as that of $Ω^{0}_{c}$ are obtained.

hep-ph↗
arXiv2017

Possible $D^{(*)}\bar{D}^{(*)}$ and $B^{(*)}\bar{B}^{(*)}$ molecular states in the extended constituent quark models

The possible neutral $D^{(*)}\bar{D}^{(*)}$ and $B^{(*)}\bar{B}^{(*)}$ molecular states are studied in the framework of the constituent quark models, which is extended by including the $s$-channel one gluon exchange. Using different types of quark-quark potentials, we solve the four-body Schrödinger equation by means of the Gaussian expansion method. The bound states of $D^{(*)}\bar{D}^{(*)}$ with $J^{PC}=1^{++},2^{++}$ and $B^{(*)}\bar{B}^{(*)}$ with $J^{PC}=0^{++},1^{+-},1^{++},2^{++}$ are obtained. The molecular states $D^{*}\bar{D}$ with $J^{PC}=1^{++}$ and $B^{*}\bar{B}$ with $J^{PC}=1^{+-}$ are good candidates for the $X(3872)$ and $Z^0_b(10610)$, respectively.

hep-ph↗
arXiv2017

Heavy pentaquark states and a novel color structure

Encouraged by the observation of the pentaquark states $P^+_c(4380)$ and $P^+_c(4450)$, we propose a novel color flux-tube structure, pentagonal state, for pentaquark states within the framework of color flux-tube mode involving a five-body confinement potential. Numerical results on the heavy pentaquark states indicate that the states with three color flux-tube structures, diquark, octet and pentagonal structures, have the close masses, which can therefore be called QCD isomers analogous to isomers in Chemistry. The pentagonal structure has lowest energy. The state $P^+_c(4380)$ can be described as the compact pentaquark state $uudc\bar{c}$ with the pentagonal structure and $J^P=\frac{3}{2}^-$ in the color flux-tube model. The state $P^+_c(4450)$ can not be accommodated into the color flux-tube model. The heavy pentaquark states $uudc\bar{b}$, $uudb\bar{c}$ and $uudb\bar{b}$ are predicted in the color flux-tube model. The five-body confinement potential basing on the color flux-tube picture as a collective degree of freedom is a dynamical mechanism in the formation of the compact heavy pentaquark states.

hep-ph↗
arXiv2016

$ND$ and $NB$ systems in quark delocalization color screening model

The $ND$ and $NB$ systems with $I=0$ and $1$, $J^{P}=\frac{1}{2}^{\pm}$, $\frac{3}{2}^{\pm}$, and $\frac{5}{2}^{\pm}$ are investigated within the framework of quark delocalization color screening model. The results show that all the positive parity states are unbound. By coupling to the $ND^{*}$ channel, the state $ND$ with $I=0,~J^{P}=\frac{1}{2}^{-}$ can form a bound state, which can be invoked to explain the observed $Σ(2800)$ state. The mass of the $ND^{*}$ with $I=0,~J^{P}=\frac{3}{2}^{-}$ is close to that of the reported $Λ_{c}(2940)^{+}$, which indicates that $Λ_{c}(2940)^{+}$ can be explained as a $ND^{*}$ molecular state in QDCSM. Besides, the $ΔD^{*}$ with $I=1,~J^{P}=\frac{5}{2}^{-}$ is also a possible resonance state. The results of the bottom case of $NB$ system are similar to those of the $ND$ system. Searching for these states will be a challenging subject of experiments.

hep-ph↗
arXiv2016

Possible pentaquarks with heavy quarks

Inspired by the discovery of two pentaquarks $P_{c}(4380)$ and $P_{c}(4450)$ at the LHCb detector, we study possible hidden-charm molecular pentaquarks in the framework of quark delocalization color screening model. Our results suggest that both $Nη_{c}$ with $IJ^{P}=\frac{1}{2}\frac{1}{2}^{-}$ and $NJ/ψ$ with $IJ^{P}=\frac{1}{2}\frac{3}{2}^{-}$ are bounded by channels coupling. However, $NJ/ψ$ with $IJ^{P}=\frac{1}{2}\frac{3}{2}^{-}$ may be a resonance state in the $D-$wave $Nη_{c}$ scattering process. Moreover, $P_{c}(4380)$ can be explained as the molecular pentaquark of $Σ^{*}_{c}D$ with quantum numbers $IJ^{P}=\frac{1}{2}\frac{3}{2}^{-}$. The state $Σ^{*}_{c}D^{*}$ with $IJ^{P}=\frac{1}{2}\frac{5}{2}^{-}$ is a resonance, it may not be a good candidate of the observed $P_{c}(4450)$ because of the opposite parity of the state to $P_{c}(4380)$, although the mass of the state is not far from the experimental value. In addition, the calculation is extended to the hidden-bottom pentaquarks, the similar properties as that of hidden-charm pentaquarks system are obtained.

hep-ph↗
arXiv2016

Is the exotic $X(5568)$ a bound state?

Stimulated by the recent observation of the exotic $X(5568)$ state by D0 Collaboration, we study the four-quark system $us\bar{b}\bar{d}$ with quantum numbers $J^P=0^+$ in the framework of chiral quark model. Two structures, diquark-antidiquark and meson-meson, with all possible color configurations are investigated by using Gaussian expansion method. The results show that energies of the tetraquark states with diquark-antiquark structure are too high to the candidate of $X(5568)$, and no molecular structure can be formed in our calculations. The calculation is also extended to the four-quark system $us\bar{c}\bar{d}$ and the same results as that of $us\bar{b}\bar{d}$ are obtained.

hep-ph↗
arXiv2015

The structure of pentaquarks $P_c^+$ in the chiral quark model

The recent experimental results of LHCb collaboration suggested the existence of pentaquark states with charmonium. To understand the structure of the states, a dynamical calculation of 5-quark systems with quantum numbers $IJ^P=\frac{1}{2}(\frac{1}{2})^\pm$, $\frac{1}{2}(\frac{3}{2})^\pm$ and $\frac{1}{2}(\frac{5}{2})^\pm$ is performed in the framework of chiral quark model with the help of gaussian expansion method. The results show that the negative parity states can be bound states while all of the positive parity states are the scattering states. The $P_c(4380)$ state is suggested to be the bound state of $Σ^*_cD$. Although the energy of $Σ_cD^*$ is very close to the mass of $P_c(4450)$, the inconsistent parity prevents the assignment. The calculated distances between quarks confirm the molecular nature of the states. Other five-quark bound states of the combination of $Σ_cD$ and $Σ^*_cD^*$ are also found in the region about 4.3GeV and 4.5GeV.

hep-ph↗
arXiv2015

Further study of the $NΩ$ dibaryon within constituent quark models

Inspired by the discovery of the dibaryon $d^{*}$ and the experimental search of $NΩ$ dibaryon with the STAR data, we study the strange dibaryon $NΩ$ further in the framework of quark delocalization color screening model and chiral quark model. We have shown $NΩ$ is a narrow resonance in $ΛΞ$ D-wave scattering before. However, the $Λ$-$Ξ$ scattering data analysis is quite complicated. Here we calculate the low-energy $NΩ$ scattering phase shifts, scattering length, effective range and binding energy to provide another approach of STAR data analysis. Our results show there exists an $NΩ$ "bound" state, which can be observed by the $N$-$Ω$ 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 $NΩ$ system to develop intermediate-range attraction.

hep-ph↗
arXiv2015

Systematic study of $Z^+_c$ family from quark model's perspective

Inspired by the present experimental status of charged charmonium-like states $Z_c^+$, the tetraquark states $[cu][\bar{c}\bar{d}]$ are systematically studied in a color flux-tube model with a multi-body confinement potential. The investigation indicates that charged charmonium-like states $Z_c^+(3900)$ or $Z_c^+(3885)$, $Z_c^+(3930)$, $Z_c^+(4020)$ or $Z_c^+(4025)$, $Z_1^+(4050)$, $Z_2^+(4250)$, and $Z_c^+(4200)$ can be uniformly described as tetraquark states $[cu][\bar{c}\bar{d}]$ with the quantum numbers $n^{2S+1}L_J$ and $J^P$ of $1^{3}S_1$ and $1^+$, $2^{3}S_1$ and $1^+$, $1^5S_2$ and $2^+$, $1^3P_1$ and $1^-$, $1^5D_1$ and $1^+$, and $1^3D_1$ and $1^+$, respectively. The predicted lowest charged tetraquark state $[cu][\bar{c}\bar{d}]$ with $0^+$ and $1^1S_0$ has a energy of $3780\pm10$ MeV in the model. The tetraquark states are compact three-dimensional spatial configurations similar to a rugby ball, the higher orbital angular momentum $L$ between the diquark $[cu]$ and antidiquark $[\bar{c}\bar{d}]$, the more prolate of the states. The multibody color flux-tube, a collective degree of freedom, plays an important role in the formation of those charge tetraquark states. However, the two heavier charged states $Z^+_c(4430)$ and $Z^+_c(4475)$ can not be explained as tetraquark states $[cu][\bar{c}\bar{d}]$ in this model approach.

hep-ph↗
arXiv2015

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 $ε(s)$ 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 $ε(s)$ used in QDCSM is an economic and effective way to describe the mixing of quarks between baryons.

hep-ph↗
arXiv2014

Theoretical study of a $d^{*}$ resonance in $^{3}G_{3}$ 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 $^{3}D_{3}$ - $^{3}G_{3}$ partial waves as expected from the $d^{*}$ resonance hypothesis, we calculated the resonance structure in the coupled $^{3}D_{3}$ - $^{3}G_{3}$ 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 $^{7}S_{3}^{ΔΔ}$ in the coupled $^{3}D_{3}^{NN}$ and $^{3}G_{3}^{NN}$ partial waves in both of these two models, which is in accordance with the expectation from the $d^{*}$ resonance structure. The resonance shape in the $^{3}D_{3}^{NN}$ partial wave is remarkable, whereas in the $^{3}G_{3}^{NN}$ 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.

nucl-th↗
arXiv2014

Radially Excited States of $η_c$

In the framework of chiral quark model, the mass spectrum of $η_c(ns) (n=1,...,6)$ is studied with Gaussian expansion method. With the wave functions obtained in the study of mass spectrum, the open flavor two-body strong decay widths are calculated by using $^3P_0$ model. The results show that the masses of $η_c(1S)$ and $η_c(2S)$ are consistent with the experimental data. The explanation of X(3940) as $η_c(3S)$ is disfavored for X(3940) is a narrow state, $Γ=37^{+26}_{-15} \pm 8 $ MeV, while the open flavor two-body strong decay width of $η_c(3S)$ is about 200 MeV in our calculation. Although the mass of X(4160) is about 100 MeV less than that of $η_c(4S)$, the assignment of X(4160) as $η_c(4S)$ can not be excluded because the open flavor two-body strong decay width of $η_c(4S)$ is consistent with the experimental value of X(4160) and the branching ratios of $η_c(4S)$ are compatible with that of X(4160), and the mass of $η_c(4S)$ can be shifted downwards by taking into account the coupling effect of the open charm channels. There are still no good candidates to $η_c(5S)$ and $η_c(6S)$.

hep-ph↗
arXiv2014

Interpreting $Z_c(3900)$ and $Z_c(4025)/Z_c(4020)$ as charged tetraquark states

In the framework of color flux-tube model with a four-body confinement potential, the lowest charged tetraquark states $[Qq][\bar{Q}'\bar{q}']~(Q=c,b,q=u,d,s)$ 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 $Q\bar{q}'$ and $\bar{Q}'q$ through the breakdown and recombination of color flux tubes but into $Q\bar{Q}'$ and $q\bar{q}'$. 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 $Z_c(3900)$ and $Z_c(4025)/Z_c(4020)$ can be accommodated in the color flux-tube model and can be interpreted as the $S$-wave tetraquark states $[cu][{\bar{c}\bar{d}}]$ with quantum numbers $I=1$ and $J=1$ and 2, respectively.

hep-ph↗
arXiv2013

Dynamical calculation of the $ΔΔ$ dibaryon candidates

We perform a dynamical calculation of the $ΔΔ$ dibaryon candidates with $IJ^{P}=03^{+}$ and $IJ^{P}=30^{+}$ in the framework of two constituent quark models: the quark delocalization color screening model and the chiral quark model. Our results show that the dibaryon resonances with $IJ^{P}=03^{+}$ and $IJ^{P}=30^{+}$ can be formed in both models. The mass and width of $IJ^{P}=03^{+}$ state are smaller than that of $IJ^{P}=30^{+}$ state due to the one-gluon-exchange interaction between quarks. The resonance mass and decay width of $IJ^{P}=03^{+}$ state in both models agree with that of the recent observed resonance in the reaction $pn \rightarrow dπ^{0}π^{0}$. The $IJ^{P}=30^{+}$ $ΔΔ$ is another dibaryon candidate with smaller binding energy and larger width. The hidden-color channel coupling is added to the chiral quark model, and we find it can lower the mass of the dibaryons by 10-20 MeV.

hep-ph↗
arXiv2013

Possible $H$-like dibaryon states with heavy quarks

Possible $H$-like dibaryon states $Λ_{c}Λ_{c}$ and $Λ_{b}Λ_{b}$ are investigated within the framework of quark delocalization color screening model. The results show that the interaction between two $Λ_{c}$'s is repulsive, so it cannot be bound state by itself. However, the strong attraction in $Σ_{c}Σ_{c}$ and $Σ^{*}_{c}Σ^{*}_{c}$ channels and the strong channel coupling, due to the central interaction of one-gluon-exchange and one-pion-exchange, among $Λ_{c}Λ_{c}$, $Σ_{c}Σ_{c}$ and $Σ^{*}_{c}Σ^{*}_{c}$ push the energy of system below the threshold of $Λ_{c}Λ_{c}$ by $22$ MeV. The corresponding system $Λ_{b}Λ_{b}$ has the similar properties as that of $Λ_{c}Λ_{c}$ system, and a bound state is also possible in $Λ_{b}Λ_{b}$ system.

hep-ph↗