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Jian-Rong Zhang

Publications and source records attributed to Jian-Rong Zhang.

At least 19 recordsLinked to original sources
arXiv2025

Fully heavy pentaquark states from QCD sum rules

In this work, we systematically investigate the mass spectra of fully heavy pentaquark states $QQQQ\bar{Q}$ within the framework of QCD sum rules. Employing three configurations of interpolating currents, we obtain the following mass predictions: for the $cccc\bar{c}$ states, the masses are determined to be $7.79^{+0.18}_{-0.17}$ GeV, $7.76^{+0.23}_{-0.18}$ Gev, $7.81^{+0.17}_{-0.18}$ GeV; while for the $bbbb\bar{b}$ states, the corresponding masses are calculated as $22.35^{+0.19}_{-0.19}$ GeV, $22.27^{+0.22}_{-0.22}$ GeV, $22.37^{+0.18}_{-0.20}$ GeV, respectively.

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arXiv2020

Fully-heavy pentaquark states

Developing the calculation techniques to fivefold heavy hadrons, we perform the study of novel fully-heavy $QQQQ\bar{Q}$ pentaquark states by the QCD sum rule approach that is firmly based on the QCD basic theory. Numerically, masses of fully-heavy pentaquark states are calculated to be $7.41^{+0.27}_{-0.31}~\mbox{GeV}$ for $cccc\bar{c}$ and $21.60^{+0.73}_{-0.22}~\mbox{GeV}$ for $bbbb\bar{b}$, respectively. In experiment, these predicted all-heavy pentaquark states could be searched for in the $\Omega_{QQQ}\eta_{Q}$ invariant mass spectrum.

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arXiv2020

$0^{+}$ fully-charmed tetraquark states

Motivated by the LHCb's new observation of structures in the $J/\psi$-pair invariant mass spectrum, for which could be classified as possible $cc\bar{c}\bar{c}$ tetraquark candidates, we systematically study $0^{+}$ fully-charmed tetraquark states through QCD sum rules. Making the development of calculation techniques to fourfold heavy hadronic systems, four different configuration currents with $0^{+}$ are considered and vacuum condensates up to dimension $6$ are included in the operator product expansion (OPE). Finally, mass values acquired for $0^{+}$ $cc\bar{c}\bar{c}$ tetraquark states agree well with the experimental data of the broad structure, which supports that it could be a $0^{+}$ fully-charmed tetraquark state.

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arXiv2020

An open charm tetraquark candidate: note on $X_{0}(2900)$

Motivated by the LHCb's very recent observation of exotic $X_{0}(2900)$ in the $B^{+}\rightarrow D^{+}D^{-}K^{+}$ process, for which could be a good open charm $ud\bar{c}\bar{s}$ tetraquark candidate, we endeavor to investigate its possibility by means of QCD sum rules. In technique, four configurations of interpolating currents with $J^{P}=0^{+}$ are studied for the $ud\bar{c}\bar{s}$ tetraquark state. In the end, mass values are calculated to be $2.76^{+0.16}_{-0.23}~\mbox{GeV}$ for the axial vector diquark-axial vector antidiquark configuration and $2.75^{+0.15}_{-0.24}~\mbox{GeV}$ for the scalar diquark-scalar antidiquark configuration, both of which are consistent with the experimental data $2.866\pm0.007\pm0.002~\mbox{GeV}$ of $X_{0}(2900)$ in view of the uncertainty. These results support that $X_{0}(2900)$ could be a $0^{+}$ tetraquark state with open charm flavor.

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arXiv2020

Looking for a vector charmonium-like state $Y$ in $e^{+}e^{-}\rightarrow\bar{D}D_{1}(2420)+c.c.$

Inspired by the first observation of a vector charmonium-like state $Y(4626)$ decaying to a meson pair $D_{s}^{+}D_{s1}(2536)^{-}$, which could be viewed as a $P$-wave scalar-scalar $[cs][\bar{c}\bar{s}]$ tetraquark state, we predict a potential vector charmonium-like state $Y$ with $P$-wave scalar-scalar $[cq][\bar{c}\bar{q}]$ configuration. The corresponding mass spectrum of $Y$ state is calculated to be $4.33^{+0.16}_{-0.23}~\mbox{GeV}$ in the framework of QCD sum rules. We suggest that the predicted $Y$ state could be looked for in an open-charm $e^{+}e^{-}\rightarrow\bar{D}D_{1}(2420)+c.c.$ process.

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arXiv2020

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

Motivated by the Belle Collaboration's new observation of $Y(4626)$, we investigate the possibility of its configuration as a $P$-wave $[cs][\bar{c}\bar{s}]$ tetraquark state from QCD sum rules. Eventually, the extracted mass $4.60^{+0.13}_{-0.19}~\mbox{GeV}$ for the $P$-wave $cs$-scalar-diquark $\bar{c}\bar{s}$-scalar-antidiquark state agrees well with the experimental data of $Y(4626)$, which could support its interpretation as a $P$-wave scalar-scalar $[cs][\bar{c}\bar{s}]$ tetraquark state.

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arXiv2019

Exploring a $\Sigma_{c}\bar{D}$ state: with focus on $P_{c}(4312)^{+}$

Stimulated by the new discovery of $P_{c}(4312)^{+}$ by LHCb Collaboration, we endeavor to perform the study of $P_{c}(4312)^{+}$ as a $\Sigma_{c}\bar{D}$ state in the framework of QCD sum rules. Taking into account the results from two sum rules, a conservative mass range $4.07\sim4.97~\mbox{GeV}$ is presented for the $\Sigma_{c}\bar{D}$ hadronic system, which agrees with the experimental data of $P_{c}(4312)^{+}$ and could support its interpretation as a $\Sigma_{c}\bar{D}$ state.

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arXiv2018

Revisiting $D_{s0}^{*}(2317)$ as a $0^{+}$ tetraquark state from QCD sum rules

Stimulated by the renewed observation of $D_{s0}^{*}(2317)$ signal and its updated mass value $2318.3\pm1.2\pm1.2~\mbox{MeV}/c^{2}$ in the process $e^{+}e^{-}\rightarrow D_{s}^{*+}D_{s0}^{*}(2317)^{-}+c.c.$ by BESIII Collaboration, we devote to reinvestigate $D_{s0}^{*}(2317)$ as a $0^{+}$ tetraquark state from QCD sum rules. Technically, four different possible currents are adopted and high condensates up to dimension $12$ are included in the operator product expansion (OPE) to ensure the quality of QCD sum rule analysis. In the end, we obtain the mass value $2.37^{+0.50}_{-0.36}~\mbox{GeV}$ with the factorization parameter $\rho=1$ (or $2.23^{+0.78}_{-0.24}~\mbox{GeV}$ with $\rho=3$) for the scalar-scalar current, which agrees well with the experimental data of $D_{s0}^{*}(2317)$ and could support its explanation as a $0^{+}$ scalar-scalar tetraquark state. The final result for the axial-axial configuration is calculated to be $2.51^{+0.61}_{-0.43}~\mbox{GeV}$ with $\rho=1$ (or $2.52^{+0.76}_{-0.52}~\mbox{GeV}$ with $\rho=3$), which is still consistent with the mass of $D_{s0}^{*}(2317)$ considering the uncertainty, and then the possibility of $D_{s0}^{*}(2317)$ as a axial-axial tetraquark state can not be excluded. For the pseudoscalar-pseudoscalar and the vector-vector cases, their unsatisfactory OPE convergence makes that it is of difficulty to find rational work windows to further acquire hadronic masses.

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arXiv2017

$0^{+}$ tetraquark states from improved QCD sum rules: delving into $X(5568)$

In order to investigate the possibility of the recently observed $X(5568)$ being a $0^{+}$ tetraquark state, we make an improvement to the study of the related various configuration states in the framework of the QCD sum rules. Particularly, to ensure the quality of the analysis, condensates up to dimension $12$ are included to inspect the convergence of operator product expansion (OPE) and improve the final results of the studied states. We note that some condensate contributions could play an important role on the OPE side. By releasing the rigid OPE convergence criterion, we arrive at the numerical value $5.57^{+0.35}_{-0.23}~\mbox{GeV}$ for the scalar-scalar diquark-antidiquark $0^{+}$ state, which agrees with the experimental data for the $X(5568)$ and could support its interpretation in terms of a $0^{+}$ tetraquark state with the scalar-scalar configuration. The corresponding result for the axial-axial current is calculated to be $5.77^{+0.44}_{-0.33}~\mbox{GeV}$, which is still consistent with the mass of $X(5568)$ in view of the uncertainty. The feasibility of $X(5568)$ being a tetraquark state with the axial-axial configuration therefore cannot be definitely excluded. For the pseudoscalar-pseudoscalar and the vector-vector cases, their unsatisfactory OPE convergence make it difficult to find reasonable work windows to extract the hadronic information.

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arXiv2014

$D_{sJ}(2860)$ From The Semileptonic Decays Of $B_s$ Mesons

In the framework of heavy quark effective theory, the leading order Isgur-Wise form factors relevant to semileptonic decays of the ground state $\bar{b}s$ meson $B_{s}$ into orbitally excited $D$-wave $\bar{c}s$ mesons, including the newly observed narrow $D^{*}_{s1}(2860)$ and $D^{*}_{s3}(2860)$ states by the LHCb Collaboration, are calculated with the QCD sum rule method. With these universal form factors, the decay rates and branching ratios are estimated. We find that the decay widths are $\Gamma(B_s\rightarrow D^{*}_{s1}\ell\bar{\nu}) =1.25^{+0.80}_{-0.60}\times10^{-19} \mbox{GeV}$, $\Gamma(B_s\rightarrow D^{'}_{s2}\ell\bar{\nu}) =1.49^{+0.97}_{-0.73}\times10^{-19} \mbox{GeV}$, $\Gamma(B_s\rightarrow D_{s2}\ell\bar{\nu}) =4.48^{+1.05}_{-0.94}\times10^{-17} \mbox{GeV}$, and $\Gamma(B_s\rightarrow D^{*}_{s3}\ell\bar{\nu}) = 1.52^{+0.35}_{-0.31}\times10^{-16} \mbox{GeV}$. The corresponding branching ratios are $\mathcal {B}(B_s\rightarrow D^{*}_{s1}\ell\bar{\nu}) =2.85^{+1.82}_{-1.36}\times 10^{-7}$, $\mathcal {B}(B_s\rightarrow D^{'}_{s2}\ell\bar{\nu}) =3.40^{+2.21}_{-1.66}\times 10^{-7}$, $\mathcal {B}(B_{s}\rightarrow D_{s2}\ell\bar{\nu}) =1.02^{+0.24}_{-0.21}\times 10^{-4}$, and $\mathcal {B}(B_s\rightarrow D^{*}_{s3}\ell\bar{\nu}) = 3.46^{+0.80}_{-0.70}\times 10^{-4}$. The decay widths and branching ratios of corresponding $B^{*}_{s}$ semileptonic processes are also predicted.

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arXiv2014

Chiral symmetry-breaking corrections to strong decays of D*s0(2317) and D's1(2460) in HH\c{hi}PT

The strong decays of two narrow mesons $D_{s0}^{*}(2317)$ and $D_{s1}^{'}(2460)$ are studied within the framework of heavy hadron chiral perturbation theory. Up to next-to-leading order in $1/\Lambda_{\chi}$, by a fit to the experimental widths of their nonstrange partners, the chiral symmetry-breaking coupling constants are extracted. The single-pion decay widths are estimated to be $\Gamma(D_{s0}^{*}(2317)\to D_{s}^{+}\pi^{0})=9.2\pm2.3$ KeV and $\Gamma(D_{s1}^{'}(2460)\to D_{s}^{*+}\pi^{0})=9.0\pm2.1$ KeV, respectively, which are consistent with the experimental constraints and comparable with other theoretical predictions. The numerical analysis shows that chiral-symmetry corrections to the decay widths are significant. Applications and predictions for the corresponding beauty mesons are also provided.

hep-ph↗
arXiv2014

$S$-wave $D^{(*)}N$ molecular states: $Σ_{c}(2800)$ and $Λ_{c}(2940)^{+}$?

Theoretically, some works have proposed the hadronic resonances $Σ_{c}(2800)$ and $Λ_{c}(2940)^{+}$ to be $S$-wave $DN$ and $D^{*}N$ molecular candidates, respectively. In the framework of QCD sum rules, we investigate that whether $Σ_{c}(2800)$ and $Λ_{c}(2940)^{+}$ could be explained as the $S$-wave $DN$ state with $J^{P}=\frac{1}{2}^{-}$ and the $S$-wave $D^{*}N$ state with $J^{P}=\frac{3}{2}^{-}$, respectively. Technically, contributions of operators up to dimension $12$ are included in the operator product expansion (OPE). The final results are $3.64\pm0.33~\mbox{GeV}$ and $3.73\pm0.35~\mbox{GeV}$ for the $S$-wave $DN$ state of $J^{P}=\frac{1}{2}^{-}$ and the $S$-wave $D^{*}N$ state of $J^{P}=\frac{3}{2}^{-}$, respectively. They are somewhat bigger than the experimental data of $Σ_{c}(2800)$ and $Λ_{c}(2940)^{+}$, respectively. In view of that corresponding molecular currents are constructed from local operators of hadrons, the possibility of $Σ_c(2800)$ and $Λ_{c}(2940)^{+}$ as molecular states can not be arbitrarily excluded merely from these disagreements between molecular masses using local currents and experimental data. But then these results imply that $Σ_{c}(2800)$ and $Λ_{c}(2940)^{+}$ could not be compact states. This may suggest a limitation of the QCD sum rule using the local current to determine whether some state is a molecular state or not. As byproducts, masses for their bottom partners are predicted to be $6.97\pm0.34~\mbox{GeV}$ for the $S$-wave $\bar{B}N$ state of $J^{P}=\frac{1}{2}^{-}$ and $6.98\pm0.34~\mbox{GeV}$ for the $S$-wave $\bar{B}^{*}N$ state of $J^{P}=\frac{3}{2}^{-}$.

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arXiv2013

Improved QCD sum rule study of $Z_{c}(3900)$ as a $\bar{D}D^{*}$ molecular state

In the framework of QCD sum rules, we present an improved study of our previous work [Phys. Rev. D {\bf80}, 056004 (2009)] particularly on the $\bar{D}D^{*}$ molecular state to investigate that the possibility of the newly observed $Z_{c}(3900)$ as a $S$-wave $\bar{D}D^{*}$ molecular state. To ensure the quality of QCD sum rule analysis, contributions of up to dimension nine are calculated to test the convergence of operator product expansion (OPE). We find that the two-quark condensate $<\bar{q}q>$ is very large and makes the standard OPE convergence (i.e. the perturbative at least larger than each condensate contribution) happen at very large values of Borel parameters. By releasing the rigid OPE convergence criterion, one could find that the OPE convergence is still under control. We arrive at the numerical result $3.86\pm0.27 {GeV}$ for $\bar{D}D^{*}$, which agrees with the mass of $Z_{c}(3900)$ and could support the explanation of $Z_{c}(3900)$ in terms of a $S$-wave $\bar{D}D^{*}$ molecular state.

hep-ph↗
arXiv2013

Study of $X_{c}(3250)$ as a $D_{0}^{*}(2400)N$ molecular state

We present a QCD sum rule analysis for the newly observed resonance $X_{c}(3250)$ by assuming it as a $D_{0}^{*}(2400)N$ molecular state. Technically, contributions of operators up to dimension 12 are included in the operator product expansion (OPE). We find that it is difficult to find the conventional OPE convergence in this work. By trying releasing the rigid OPE convergence criterion, one could find that the OPE convergence is still under control in the present work and the numerical result for $D_{0}^{*}(2400)N$ state is $3.18\pm0.51 {GeV}$, which is in agreement with the experimental data of $X_{c}(3250)$. In view of that the conventional OPE convergence is not obtained here, thus only weak conclusions can be drawn regarding the explanation of $X_{c}(3250)$ in terms of a $D_{0}^{*}(2400)N$ molecular state. As a byproduct, the mass for the bottom counterpart $\bar{B}_{0}^{*}N$ state is predicted to be $6.50\pm0.49 {GeV}$.

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arXiv2012

New molecular candidates: X(1910), X(2200), and X(2350)

Assuming the newly observed resonant structures X(1910), X(2200), and X(2350) as $\omega\omega$, $\omega\phi$, and $\phi\phi$ molecular states respectively, we compute their mass values in the framework of QCD sum rules. The numerical results are $1.97\pm0.17 {GeV}$ for $\omega\omega$ state, $2.07\pm0.21 {GeV}$ for $\omega\phi$ state, and $2.18\pm0.29 {GeV}$ for $\phi\phi$ state, which coincide with the experimental values of X(1910), X(2200), and X(2350), respectively. This supports the statement that X(1910), X(2200), and X(2350) could be $\omega\omega$, $\omega\phi$, and $\phi\phi$ molecular candidates respectively.

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arXiv2012

Search for $Z^{+}_{s1}$ and $Z^{+}_{s2}$ strangeonium-like structures

Theoretically, it has been presumed from an effective Lagrangian calculation that there could exist two charged strangeonium-like molecular states $Z^{+}_{s1}$ and $Z^{+}_{s2}$, with $K\bar{K}^{*}$ and $K^{*}\bar{K}^{*}$ configurations respectively. In the framework of QCD sum rules, we predict that masses of $Z^{+}_{s1}$ ($K\bar{K}^{*}$) and $Z^{+}_{s2}$ ($K^{*}\bar{K}^{*}$) are $1.85\pm0.14 GeV$ and $2.02\pm0.15 GeV$ respectively, which are both above their respective two meson thresholds. We suggest to put in practice the search for these two charged strangeonium-like structures in future experiments.

hep-ph↗
arXiv2011

Could $Z_{b}(10610)$ be a $B^{*}\bar{B}$ molecular state?

Assuming the newly observed structure $Z_{b}(10610)$ as a bottomonium-like molecular state $B^{*}\bar{B}$, we calculate its mass in the framework of QCD sum rules. The numerical result is $10.54\pm0.22 GeV$ for $B^{*}\bar{B}$, which coincide with the mass of $Z_{b}(10610)$. This consolidates the statement made by Belle Collaboration that the $Z_{b}(10610)$ resonance could be a $B^{*}\bar{B}$ molecular state.

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