arXiv subjects

Jialun Ping

Publications and source records attributed to Jialun Ping.

At least 91 records · Page 5Linked to original sources

arXiv2020

Investigation of $qqqs\bar q$ pentaquarks in a chiral quark model

We investigate the pentaquark system $qqqs \bar q$ in a framework of chiral quark model. Two structures, $(qqq)(s\bar{q})$ and $(qqs)(q\bar{q})$, with all possible color, spin, flavor configurations are considered. The calculations show that there are several possible resonance states, $Sigma π$ and $N \bar{K}$ state with $IJ^P=0\frac{1}{2}^-$, $Σ^* π$ with $IJ^P=0\frac{3}{2}^-$, $Σ^* ρ$ with $IJ^P=0\frac{5}{2}^-$, $Δ\bar{K}$ with $IJ^P=1\frac{3}{2}^-$ and $Δ\bar{K}^*$ with $IJ^P=1\frac{5}{2}^-$. Where the $N \bar{K}$ state with $IJ^P=0\frac{1}{2}^-$ can be used to explain the $Λ(1405)$, and together with another state $Σπ$ is related to the two-pole structure of the scattering amplitude proposed before. The decay properties of $Λ(1520)$ prevent the assignment of $Σ^* π$ with $IJ^P=0\frac{3}{2}^-$ to $Λ(1520)$, although the energy $\sim$ 1518 MeV of $Σ^* π$ is close to experimental value of $Λ(1520)$. Other resonance states generally have a large width.

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arXiv2020

$QQ\bar{s}\bar{s}$ tetraquarks in the chiral quark model

The low-lying $S$-wave $QQ\bar{s}\bar{s}$ ($Q=c, b$) tetraquark states with $IJ^P=00^+$, $01^+$ and $02^+$ are systematically investigated in the framework of complex scaling range of chiral quark model. Every structure including meson-meson, diquark-antidiquark and K-type configurations, and all possible color channels in four-body sector are considered by means of a commonly extended variational approach, Gaussian expansion method. Several narrow and wide resonance states are obtained for $cc\bar{s}\bar{s}$ and $bb\bar{s}\bar{s}$ tetraquarks with $IJ^P=00^+$ and $02^+$. Meanwhile, narrow resonances for $cb\bar{s}\bar{s}$ tetraquarks are also found in $IJ^P=00^+$, $01^+$ and $02^+$ states. These results confirm the possibility of finding hadronic molecules with masses $\sim\,0.6\,\text{GeV}$ above the noninteracting hadron-hadron thresholds.

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arXiv2020

Full-heavy tetraquarks in constituent quark models

The full-heavy tetraquarks $bb\bar{b}\bar{b}$ and $cc\bar{c}\bar{c}$ are systematically investigated within the chiral quark model and the quark delocalization color screening model. Two structures, meson-meson and diquark-antidiquark, are considered. For the full-beauty $bb\bar{b}\bar{b}$ systems, there is no any bound state or resonance state in two structures in the chiral quark model, while the wide resonances with masses around 19.25 GeV and the quantum numbers $J^{P}=0^{+}$, $1^{+}$, and $2^{+}$ are possible in the quark delocalization color screening model. For the full-charm $cc\bar{c}\bar{c}$ systems, the results are qualitative consistent in two quark models. No bound state can be found in the meson-meson configuration, while in the diquark-antidiquark configuration there may exist the resonance states, with masses range between $6.3$ GeV to $7.4$ GeV, and the quantum numbers $J^{P}=0^{+}$, $1^{+}$, and $2^{+}$. And the separation between the diquark and the antidiquark indicates that these states may be the compact resonance states. All these full-charm resonance states are consistent with the latest results at LHCb collaboration and are worth searching in the experiments further.

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arXiv2020

Study of the hidden charm pentaquarks $Λ_{c\bar{c}}$ above $4$ GeV

A dynamical calculation of the strange hidden charm pentaquark systems $Λ_{c\bar{c}}$ is performed in the framework of the quark delocalization color screening model. The effective potentials between two clusters are calculated to investigate the interaction between the baryons and mesons. The dynamic calculations indicate that the strange hidden charm pentaquark system with $IJ^{P}=0\frac{1}{2}^{-}$ and $IJ^{P}=0\frac{3}{2}^{-}$ can form bound states with the help of the channel-coupling. The energies of these two system are 4094.3 MeV and 4207.4 Mev, respectively. These two $Λ_{c\bar{c}}$ states are possible to be intriguing pentaquark candidates which are worth searching in experiments. Whereas, for the systems with isospin $I=1$, the effective potentials of all channels are repulsive, and there is no any bound state for these systems.

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arXiv2020

Are $N\barΩ$ bound states?

Inspired by the progress of the experimental search of the $NΩ$ dibaryon by the STAR collaboration, we study $N\barΩ$ systems in the framework of quark delocalization color screening model. Our results show that the attraction between $N$ and $\barΩ$ is a little bit larger than that between $N$ and $Ω$, which indicates that it is more possible for the $N\barΩ$ than the $NΩ$ system to form bound states. The dynamic calculations state that both the $J^{P}=1^{+}$ and $2^{+}$ $N\barΩ$ systems are bound states. The binding energy of these two states are deeper than that of $NΩ$ systems with $J^{P}=2^{+}$, and the $NΩ$ system with $J^{P}=1^{+}$ is unbound. The calculation of the low-energy scattering phase shifts, scattering length and the effective range also supports the existence of the $N\barΩ$ bound states with $J^{P}=1^{+}$ and $2^{+}$. So the $N\barΩ$ states are better hexaquark states and stronger signals are expected in experiments.

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arXiv2020

$QQ\bar{q}\bar{q}$ in a chiral constituent quark model

Inspired by $Ξ_{cc}$ reported by LHCb Collaboration and $X(5568)$ reported by $D0$ Collaboration, the $QQ\bar{q}\bar{q}$ ($Q=c,b,s$, $q=u,d$) tetraquark states, are studied in the present work. With the help of gaussian expansion method, two structures, diquark-antiquark and meson-meson, with all possible color configurations are investigated systematically in a chiral quark model to search for the possible stable states. The results show that there is no bound state in the isovector $QQ\bar{q}\bar{q}$ system, while there are rather deep bound states in the isoscalar $bb\bar{q}\bar{q}$, $cc\bar{q}\bar{q}$ and $bc\bar{q}\bar{q}$ systems. There are also several shallow bound states in $QQ^{\prime}$ system. Mixing two structures of diquark-antidiquark and meson-meson can introduce more attractions and convert some unbound isoscalar states into shallow bound states. The large mass of the heavy quark is beneficial to the formation of the bound state. The separations between quarks are calculated to unravel the spacial structure of the system.

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arXiv2020

Doubly Charmed Pentaquarks

The LHCb Collaboration, using its full data set from runs $1$ and $2$, announced in $2019$ a surprising update of the hidden-charm pentaquark states $P_c(4380)^+$ and $P_c(4450)^+$, observed in 2015. A new state, $P_c(4312)^+$, was clearly seen at lower energies; furthermore, the original $P_c(4450)$ resonance was resolved into two individual states, named the $P_c(4440)^+$ and the $P_c(4457)^+$. Motivated by the fact that these new hidden-charm pentaquark states were successfully predicted by our chiral quark model, we extend herein such study to the doubly charmed sector. The analyzed total spin and parity quantum numbers are $J^P=\frac12^-$, $\frac32^-$ and $\frac52^-$, in the $I=\frac12$ and $\frac32$ isospin channels. We find several possible narrow baryon-meson resonances (theoretical masses in parenthesis): $IJ^P = \frac12 \frac12^-$ $Σ_c D(4356)$, $\frac12 \frac32^-$ $Σ^*_c D(4449)$, $\frac32 \frac12^-$ $Σ_c D(4431)$, $\frac32 \frac12^-$ $Σ_c D(4446)$, $\frac32 \frac32^-$ $Σ_c D^*(4514)$ and $\frac32 \frac52^-$ $Ξ^*_{cc} ρ(4461)$ whose widths are $4.8$, $8.0$, $2.6$, $2.2$, $4.0$ and $3.0\,\text{MeV}$, respectively. Moreover, one shallow bound-state is found, too, with quantum numbers $IJ^P = \frac12 \frac32^-$ $Ξ^*_{cc} π(3757)$. These doubly charmed pentaquark states are expected to be identified in future experiments.

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arXiv2019

Reanalysis of the most strange dibaryon within constituent quark models

The most strange dibaryon $ΩΩ$ with quantum numbers $S=-6$, $I=0$, and $J^{P}=0^{+},~1^{-},~2^{+},~3^{-}$ is reanalyzed in the framework of quark delocalization color screening model (QDCSM) and chiral quark model (ChQM). The $ΩΩ$ dibaryon with $J^{P}=0^{+}$ is bound, and the one with other quantum numbers $J^{P}=1^{-},~2^{+},~3^{-}$ are all unbound in our calculation. The low-energy scattering phase shifts, the scattering length, and the effective range of the $ΩΩ$ dibaryon with $J^{P}=0^{+}$ also support the existence of such strange dibaryon. This dibaryon is showed to be a shallow bound state in QDCSM, while the binding energy becomes much larger in the ChQM by including the effect of the hidden-color channel coupling. And the scalar nonet meson-exchange in the ChQM also provides more attraction for the $ΩΩ$ system. Experimental search for such most strange dibaryon will provide much information for understanding the hadron-hadron interactions in different quark models.

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arXiv2019

$Y(4626)$ in a chiral constituent quark model

Recently, Belle Collaboration reported a new exotic state $Y(4620)$ with mass at 4625.9 MeV in the positronium annihilation process. Inspired by experiment, we study the tetraquark system $c\bar{s}s\bar{c}$ with quantum numbers $J^{P}=1^{-}$ in the framework of chiral constituent quark model with the help of Gaussian expansion method. Two structures, diquark-antidiquark and meson-meson, with all possible color and spin configurations are considered. The result shows that no bound state can be formed. To investigate the possible resonance states, the real scaling method is employed. Several resonance states with energies 4354, 4408, 4469, 4497 and 4531 MeV, are proposed. Taking into account the errors in calculating the $q\bar{q}$ mesons, the system errors in the calculation of four-quark system are around 60$\sim 100$ MeV. The resonance with energy 4531 MeV is possible the candidate of the newly found state $Y(4620)$.

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arXiv2019

Can the state $Y(4626)$ be a $P$-wave tetraquark state $[cs][\bar{c}\bar{s}]$?

Stimulated by the state $Y(4626)$ recently reported by Belle Collaboration, we utilize a multiquark color flux-tube model with a multibody confinement potential and one-glue-exchange interaction to make an exhaustive investigation on the diquark-antidiquark state $[cs][\bar{c}\bar{s}]$. Numerical results indicate that the appearance of the states $[cs][\bar{c}\bar{s}]$ like a dumb-bell, the larger the orbital excitation $L$, the more distinguished the shape. The mixing of the color configurations $\left[[cs]_{\bar{\mathbf{3}}_c}[\bar{c}\bar{s}]_{\mathbf{3}_c}\right]_{\mathbf{1}}$ and $\left[[cs]_{\mathbf{6}_c}[\bar{c}\bar{s}]_{\bar{\mathbf{6}}_c}\right]_{\mathbf{1}}$ in the ground states is strong while the color configuration $\left[[cs]_{\bar{\mathbf{3}}_c}[\bar{c}\bar{s}]_{\mathbf{3}_c}\right]_{\mathbf{1}}$ is absolutely predominant in the excited states. The main component of the state $Y(4626)$ can be interpreted as a $P$-wave state $[cs][\bar{c}\bar{s}]$. Its hidden-bottom partner is predicted in the model calculation. The states $X(4140)$, $X(4274)$, $X(4350)$, $X(4500)$ and $X(4700)$ are also discussed.

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arXiv2019

Doubly-heavy tetraquarks

In the framework of the chiral quark model along with complex scaling range, we perform a dynamical study on the low-lying $S$-wave doubly-heavy tetraquark states ($QQ\bar{q}\bar{q}$, $Q=c, b$ and $q=u, d$) with an accurate computing approach, Gaussian expansion method. The meson-meson and diquark-antidiquark configurations within all possible color structures for spin-parity quantum numbers $J^P=0^+$, $1^+$ and $2^+$, and in the $0$ and $1$ isospin sectors are considered. Possible tightly bound and narrow resonance states are obtained for doubly-charm and doubly-bottom tetraquarks with $IJ^P=01^+$, and these exotic states are also obtained in charm-bottom tetraquarks with $00^+$ and $01^+$ quantum numbers. Only loosely bound state is found in charm-bottom tetraquarks of $02^+$ states. All of these bound states within meson-meson configurations are loosely bound whether in color-singlet channels or coupling to hidden-color ones. However compact structures are available in diquark-antidiquark channels except for charm-bottom tetraquarks in $02^+$ states.

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arXiv2019

Prediction of $NΩ$-like dibaryons with heavy quarks

Possible $NΩ$-like dibaryons $NΩ_{ccc}$ and $NΩ_{bbb}$ with quantum numbers $IJ^P=\frac{1}{2}2^+$ are investigated within the framework of quark delocalization color screening model. We find both of these two states are bound, and the binding energy increases as the quarks of the system become heavier. The attraction between $N$ and $Ω_{ccc}$ (or $Ω_{bbb}$) mainly comes from the kinetic energy term due to quark delocalization and color screening. The effect of the channel-coupling provides more effective attraction to $NΩ_{ccc}$ and $NΩ_{bbb}$ systems. Besides, the scattering length, the effective range, and the binding energy, obtained from the calculation of the low-energy scattering phase shifts, also supports the existence of the $NΩ_{ccc}$ and $NΩ_{bbb}$ states. All these properties can provide necessary information for experimental search for the $NΩ$-like dibaryons with heavy quarks. And the experimental progress can also check the mechanism of the intermediate-range attraction of the baryon-baryon interaction in quark models.

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arXiv2019

Triply-heavy baryons in a constituent quark model

A constituent quark model, which has recently been successfully applied to the study of heavy quarkonium properties such as its spectrum but also a diverse array of observables related with their electromagnetic, strong and weak decays and reactions, is used herein to compute ground- and excited-state masses of $QQQ$-baryons containing either $c$- or $b$-quarks. Considering the lack of experimental information about the spectra of triply-heavy baryons, we believe that our computation could help on finding new states, since it is expected that phenomenological quark models describe triply-heavy baryons to a similar degree of accuracy as heavy quarkonia. The quark model parameters previously used to describe $c\bar c$ and $b\bar b$ properties have not been modified for this analysis. The non-relativistic three-body bound-state problem is solved by means of the Gaußian expansion method which provides enough accuracy and simplifies the subsequent evaluation of the matrix elements. Several low-lying states with quantum numbers $J^P=\frac{1}{2}^{\pm}$, $\frac{3}{2}^{\pm}$, $\frac{5}{2}^{\pm}$ and $\frac{7}{2}^+$ are reported. We compare our results with those predicted by many other theoretical formalisms. There is a general trend of agreement about the mass of the ground state in each sector of triply-heavy baryons; however, the situation is more puzzling for the excited states and thus appropriate comments on the most relevant features of our comparison are given.

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arXiv2019

Finite volume effects on quarkonium dissociation temperature in an impenetrable QGP sphere

The system of a quarkonium confined by an impenetrable spherical cavity filled with a hot quantum chromodynamics (QCD) medium is studied by solving the Schrödinger equation. This is the first time this issue has been raised for discussion. The Schrödinger equation with an appropriate boundary condition of a quarkonium in an impenetrable cavity filled with a hot medium is derived. The numerical results are obtained with the help of Gaussian Expansion Method. Binding energies and radii of the ground and low-excited states are obtained as a function of the medium temperature and the cavity radius. We find the behaviour of quarkonium in this cavity is different from that in infinite space. Our results show that the quarkonium dissociation temperature decreases as the cavity radius decreases and the finite volume effects on the ground state are more obvious than on the excited states. We also find that the less mass of the constituents and the bigger radius of the quarkonium lead the finite volume effects to become more obvious.

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arXiv2019

X(3872) in an unquenched quark model

In this paper, we calculate mass and probability fractions of meson-meson components of $X(3872)$ in an unquenched quark model. Different from most of other unquenched quark models, the quark pairs creation operator from $^3P_0$ is modified by considering effects of the created quark pair energy and separation between the created quark pair and the valence quark-pair. In the calculation, all the wavefunctions of mesons and the relative motion between two mesons are obtained by solving the corresponding Schrödinger equation with the help of gaussian expansion method. The multi-channel coupling of quark-antiquark state with possible meson-meson states are performed. The results show that the $X(3872)$ can be described as a mixing state of dominant charmonium state (70\%) and meson-meson components (30\%).

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arXiv2019

Geometric Engineering and Almost Mathieu Operator

The type IIA string theory on a non-compact Calabi-Yau geometry known as the local $\mathbb{P}^{1} \times \mathbb{P}^{1}$ gives rise to five-dimensional N =1 supersymmetric SU(2) gauge theory compactified on a circle, known as geometric engineering. So it is necessary to study the $\mathbb{P}^{1} \times \mathbb{P}^{1}$ in details. Since the spectrum of the local $\mathbb{P}^{1} \times \mathbb{P}^{1}$ can be written as $E=R^{2}\left(\mathrm{e}^{p}+\mathrm{e}^{-p}\right)+\mathrm{e}^{x}+\mathrm{e}^{-x}$, then by the result of almost Mathieu operator, we show that: (1) when $R^{2}<1$, the spectrum is absolutely continuous which meanings the medium is conductor. (2) when $1\le R^{2} e^β$, the spectrum is almost surely pure point and exhibits Anderson localization. In other words, there are two phase transition points which one is $R^{2}=1$ and the other one is $R^{2}=e^β$.

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arXiv2019

Systematical investigation on the stability of doubly heavy tetraquark states

We systematically investigate the stability of the doubly heavy tetraquark states $[QQ][\bar{q}\bar{q}]$ ($Q=c$ and $b$, $q=u$, $d$ and $s$) within the framework of the color flux-tube model involving a multibody confinement potential, $σ$-exchange, one-gluon-exchange and one-Goldstone-boson-exchange interactions. Our numerical analysis indicates that the states $[bb][\bar{u}\bar{d}]$ with $01^+$ and $[bb][\bar{u}\bar{s}]$ with $\frac{1}{2}1^+$ are the most promising stable states against strong interactions. The states $[cc][\bar{u}\bar{d}]$ with $01^+$, $[bc][\bar{u}\bar{d}]$ with $00^+$, $01^+$, and $12^+$, and $[bb][\bar{u}\bar{d}]$ with $01^-$ and $12^+$ as stable states are also predicted in the color flux-tube model. The dynamical mechanism producing those stable doubly heavy tetraquark states are discussed in the color flux-tube model.

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arXiv2019

Investigate the pentaquark resonance in the $NK$ system

A dynamical calculation of pentaquark systems with quark contents $uudd\bar{s}$ is performed in the framework of quark delocalization color screening model with the help of resonating group method. The effective potentials between baryon and meson clusters are given, and the possible bound states or resonances are investigated. The single calculations show that the $NK^{*}$ with $I=0, J^{P}=\frac{1}{2}^{-}$, $ΔK^{*}$ with $I=1, J^{P}=\frac{1}{2}^{-}$, and $ΔK^{*}$ with $I=2, J^{P}=\frac{3}{2}^{-}$ are all bound, but they all turns into scattering states by coupling with the corresponding open channels. A possible resonance state $ΔK^{*}$ with $I=1, J^{P}=\frac{5}{2}^{-}$ is proposed. The mass is around $2110.5$ MeV, and the decay modes are $NK$ in $D$-wave or $NKππ$ in $P$-waves.

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