arXiv subjects

Chun-Yu Cui

Publications and source records attributed to Chun-Yu Cui.

13 recordsLinked to original sources

arXiv2020

$\bar{D}^{()}_{s}D^{()}$ molecular state with $J^{P}=1^{+}$

In this paper, we construct $\bar{D}^{(*)}_{s}D^{(*)}$-molecule-type interpolating currents $J_{(\pm)\mu}(x)$ with $J^{P}=1^{+}$, calculate the corresponding mass and magnetic moment using the QCD sum rule method and its extension in the weak electromagnetic field, and study the processes of $Z_{(\pm)cs}$ to $\eta_{c}K^{*}$, $J/\psi K$, $\bar{D}D^{*}_{s}$, and $\bar{D}^{*}D_{s}$ via three-point sum rules. The numerical values are $m_{Z_{(\pm)cs}}=3.99^{+0.17}_{-0.14}~\mbox{GeV}$, and $\lambda_{Z_{(\pm)cs}}=2.07^{+0.28}_{-0.16}\times10^{-2}~\mbox{GeV}^{5}$, $\mu_{Z_{(\pm)cs}}=0.18^{+0.16}_{-0.09}~\mu_{N}$ with $\mu_{N}$ the nucleon magneton, $\Gamma_{Z_{(+)cs}}=17.47^{+12.70}_{-8.08}$, and $\Gamma_{Z_{(-)cs}}=13.86^{+10.37}_{-6.51}$. The masses are in agreement with the recently measured value of $Z_{cs}(3985)$ by the BESIII Collaboration, $m^{exp}_{Z_{cs}}=(3982.5^{+1.8}_{-2.6}\pm2.1)~\mbox{MeV}$. The widths are compatible with the experimental value, $\Gamma^{exp}_{Z_{cs}}=(12.8^{+5.3}_{-4.4}\pm3.0)~\mbox{MeV}$. The magnetic moment and the various decay modes can help us to determine the inner structure of $Z_{cs}(3985)$ when being confronted with experimental data in the future.

hep-ph↗

arXiv2020

Partial decay widths of $P_{c}(4312)$ as a $\bar{D}Σ_{c}$ molecular state

In the present work, the partial decay widths of $P_{c}(4312)$ to $η_{c} p$ and $J/ψp$ are investigated with the QCD sum rule method under the assumption that $P_{c}(4312)$ is a $\bar{D}Σ_{c}$ molecular state with $J^{P}=\frac{1}{2}^{-}$. In the analysis, the pole residue of $P_{c}(4312)$, one of the input parameters for the calculations of the strong decay constants, is calculated first. With the numerical values of the strong decay constants, the partial decay widths to $η_{c} p$ and $J/ψp$ are estimated to be $Γ(P_{c}(4312)\rightarrow η_{c} p)=5.54^{+0.75}_{-0.5}\mbox{MeV}$ and $Γ(P_{c}(4312)\rightarrow J/ψp)=1.67^{+0.92}_{-0.56}\mbox{MeV}$, respectively, which are compatible with the measured total width of $P_{c}(4312)$. The results suggest that it is reasonable to assign $P_{c}(4312)$ to be a $\bar{D}Σ_{c}$ molecular state with $J^{P}=\frac{1}{2}^{-}$.

hep-ph↗

arXiv2017

Analysis of the semileptonic decay Λ_c->ne^+ν_e

The semileptonic weak decay process of the $Λ_c$ baryon to the neutron $Λ_c\rightarrow ne^+ν_e$ is examined. The transition form factors are investigated with light-cone QCD sum rules. The differential decay width is obtained in the dynamical region by fitting the sum rules-allowed results with the dipole formula. The total decay width and the branching ratio are estimated to be $Γ(Λ_c\rightarrow ne^+ν_e)=(8.57\pm0.41)\times10^{-15}\,\mbox{GeV}$ and $\mbox{Br}(Λ_c\rightarrow ne^+ν_e)=0.26\pm0.01\%$, respectively.

hep-ph↗

arXiv2014

Higher order light-cone distribution amplitudes of the Lambda baryon

The improved light-cone distribution amplitudes (LCDAs) of the $Λ$ baryon are examined on the basis of the QCD conformal partial wave expansion approach. The calculations are carried out to the next-to-leading order of conformal spin accuracy with consideration of twist 6. The next leading order conformal expansion coefficients are related to the nonperturbative parameters defined by the local three quark operator matrix elements with different Lorentz structures with a covariant derivative. The nonperturbative parameters are determined with the QCD sum rule method. The explicit expressions of the LCDAs are provided as the main results.

hep-ph↗

arXiv2014

QCD sum rules study of X(4350)

The QCD sum rule approach is used to analyze the nature of the rencently observed new resonance $X(4350)$, which is assumed to be a diquark-antidiquark state $[cs][\bar{c}\bar{s}]$ with $J^{PC}=1^{-+}$. The interpolating current representing this state is proposed. In the calculation, contributions of operators up to dimension six are included in the operator product expansion (OPE), as well as terms which are linear in the strange quark mass $m_s$. We find $m_{1^{-+}}=(4.82\pm 0.19)\,\mbox{GeV}$, which is not compatible with the $X(4350)$ structure as a $1^{-+}$ tetraquark state. Finally, we also discuss the difference of a four-quark state's mass whether the state's interpolating current has a definite charge conjugation.

hep-ph↗

arXiv2014

Could $Z_{c}(3900)$ be a $I^{G}J^{P}=1^{+}1^{+}$ $D^{*}\bar{D}$ molecular state?

We investigate the nature of the recently observed narrow resonance $Z_{c}(3900)$, which is assumed to be a $D^{*}\bar{D}$ molecular state with quantum numbers $I^{G}J^{P}=1^{+}1^{+}$. Using QCD sum rules, we consider contributions up to dimension eight in the operator product expansion and work at the leading order in $α_{s}$. The mass we arrived at is $(3.88 \pm 0.17) \mbox{GeV}$, which coincides with the mass of $Z_{c}(3900)$.

hep-ph↗

arXiv2014

Could $Z_{c}(4025)$ be a $J^{P}=1^{+}$ $D^{}\bar{D^{}}$ molecular state?

We investigate whether the newly observed narrow resonance $Z_{c}(4025)$ can be described as a $D^{*}\bar{D^{*}}$ molecular state with quantum numbers $J^{P}=1^{+}$. Using QCD sum rules, we consider contributions up to dimension six in the operator product expansion and work at leading order of $α_{s}$. The mass obtained for this state is $(4.05\pm 0.28) \mbox{GeV}$. It is concluded that $D^{*}\bar{D^{*}}$ molecular state is a possible candidate for $Z_{c}(4025)$.

hep-ph↗

arXiv2014

Higher Order Corrections to the Light-cone Distribution Amplitudes of the Sigma baryon

The Light-cone distribution amplitudes (LCDAs) of the $Σ^\pm$ baryons up to twist six are investigated on the basis of QCD conformal partial wave expansion approach. The calculations are carried out to the next-to-leading order of conformal spin accuracy. The nonperturbative parameters relevant to the LCDAs are determined in the framework of the QCD sum rule method. The explicit expressions of the LCDAs are given as the main results.

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arXiv2013

$η_{b}BB^{\ast}$ vertex from QCD sum rules

The form factor and the coupling constant in the $η_{b}BB^{\ast}$ vertex are evaluated in the framework of three-point QCD sum rules. The correlation functions responsible for the vertex is evaluated considering contributions of both $B$ and $B^{\ast}$ mesons as off-shell states. The form factors obtained are different for the two cases, whereas the final results of the coupling constant are compatible.

hep-ph↗

arXiv2012

Can X(3872) be a $J^{P}=2^{-}$ tetraquark state?

In this article, we test the nature of X(3872), which is assumed to be a P-wave $[cq]$-scalar-diquark $[\bar{c}\bar{q}]$-axial-vector-antidiquark tetraquark state with $J^{P}=2^{-}$. The interpolating current representing the $J^{P}=2^{-}$ state is proposed. Technically, contributions of the operators up to dimension six are included in the operator product expansion (OPE). The mass obtained for such state is $m_{2^{-}}=(4.38\pm 0.15) GeV$. We conclude that it is impossible to describe the X(3872) structure as $J^{P}=2^{-}$ tetraquark state.

hep-ph↗

arXiv2012

$B^{\ast}_{s1}B^{\ast}K$ form factor from QCD sum rules

In this article, we calculate the form factors and the coupling constant of the $g_{B^{\ast}_{s1}B^{\ast} K}$ vertex in the framework of the three-point QCD sum rules. Three point correlation functions responsible for the vertex are evaluated by considering both $B^{\ast}$ and $K$ mesons as off-shell states. The form factors obtained are different if the $B^{\ast}$ or the $K$ meson is off-shell but give the same coupling constant.

hep-ph↗

arXiv2012

$B^{\ast}B^{\ast}ρ$ vertex from QCD sum rules

The form factors and the coupling constants in the $B^{\ast}B^{\ast}ρ$ vertex are evaluated in the framework of three-point QCD sum rules. The correlation functions responsible for the form factors are evaluated considering contributions of both $B^{\ast}$ and $ρ$ mesons as off-shell states. The obtained numerical results for the coupling constants are in agreement with light-cone QCD sum rules calculations.

hep-ph↗

arXiv2012

Investigating different structures of the Z_{b}(10610) and Z_{b}(10650)

The recently observed narrow resonance $Z_{b}(10610)$ is examined with the assumptions both as a $B^{*}\bar{B}$ molecular state and a $[bd][\bar{b}\bar{u}]$ tetraquark state with quantum numbers $I^{G}J^{P}=1^{+}1^{+}$. Possible interpolating currents are constructed to describe the $Z_{b}(10650)$ as an axial-vector $B^{*}\bar{B}^{*}$ molecular state or a $[bd][\bar{b}\bar{u}]$ tetraquark state. Using QCD sum rules (QCDSR), we consider contributions up to dimension six in the operator product expansion (OPE) at the leading order in $α_{s}$. The mass is obtained as $(10.44\pm0.23) GeV$ for molecular state and $(10.50\pm0.19) GeV$ for tetraquark state, both of which coincide with the $Z_{b}(10610)$. The results $m_{B^{*}\bar{B}^{*}}=(10.45\pm0.31) GeV$ and $m_{[bd][\bar{b}\bar{u}]}=(10.48\pm0.33) GeV$ are consistent with the $Z_{b}(10650)$.

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