arXiv subjects

Wen-Ying Liu

Publications and source records attributed to Wen-Ying Liu.

9 recordsLinked to original sources

arXiv2026

The decay properties of two- and three- gluon glueballs

We previously studied the decay properties of two- and three-gluon glueballs using the Fierz rearrangement method and obtained their relative branching ratios in Ref.~\cite{Tan:2026uue}. In this work, we extend and develop this analysis by providing a more complete treatment of two-gluon glueball decays and by considering the tensor and pseudotensor states with $J^{PC}=2^{++}$ and $2^{-+}$. We also perform an independent QCD sum rule analysis of the $0^{++}$ two-gluon glueball decay. The consistency between the two approaches provides a useful check of the Fierz analysis. Our results support a sizable gluon component in the $f_0(1710)$ and favor the $0^{-+}$ glueball interpretation of the $η(2370)$. For the tensor glueball, the vector--vector ($VV$) decay channels, especially $K^{*}(892)\bar{K}^{*}(892)$, are found to be favorable for experimental searches. We also study three-gluon glueballs with $J^{PC}=0^{++}$ and $1^{+-}$ and identify several potentially favorable three-meson decay channels, including $ππω$ and $K\bar Kϕ$. These results provide possible guidance for future experimental searches for glueball states.

hep-ph↗

arXiv2026

Light tetraquark states with $J^{PC}=1^{--}$ from QCD sum rules

We perform a systematic QCD sum rule study of light tetraquark states with $J^{PC}=1^{--}$ in the diquark--antidiquark picture. A complete set of local interpolating currents is constructed and projected onto six flavor-isospin configurations ($q=u/d$): the isoscalar $q q\bar q\bar q$, $q s\bar q\bar s$, and $s s\bar s\bar s$ sectors, the isovector $q q\bar q\bar q$ and $q s\bar q\bar s$ sectors, and the isotensor $q q\bar q\bar q$ sector. The lowest masses in these sectors are derived to be $1.64^{+0.15}_{-0.14}$~GeV, $1.86^{+0.14}_{-0.14}$~GeV, $2.34^{+0.23}_{-0.30}$~GeV, $1.53^{+0.17}_{-0.19}$~GeV, $1.86^{+0.14}_{-0.14}$~GeV, and $2.24^{+0.12}_{-0.14}$~GeV, respectively. We further compare the present $1^{--}$ tetraquark spectrum with previous QCD sum rule results for the $1^{-+}$ tetraquark and hybrid states~\cite{Su:2025bhv}, aiming to provide useful information for distinguishing tetraquark and hybrid configurations in the light hadron spectrum. As an additional improvement, we complete the previously missing isotensor $1^{-+}$ tetraquark entry and obtain its lowest mass to be $M=2.19^{+0.26}_{-0.24}~\mathrm{GeV}$, which is included in the spectral comparison.

hep-ph↗

arXiv2025

QCD sum rule study on excited light meson operators

We apply the QCD sum rule method to systematically study excited light meson operators and calculate their decay constants. These operators are constructed by explicitly adding one covariant derivative to the quark-antiquark pair. In total, twelve such operators are constructed, among which ten are subjected to detailed numerical analyses. The considered quark contents include $\bar{q}q$, $\bar{q}s$, and $\bar{s}s$ ($q = u/d$), allowing the formation of various $SU(3)$ flavor nonets. For instance, our results support the interpretation that the $a_2(1320)$, $f_2(1270)$, $f_2^\prime(1525)$, and $K_2^*(1430)$ constitute a flavor nonet with quantum numbers $J^{P(C)} = 2^{+(+)}$. In addition, we predict several excited meson states, whose masses and decay constants are determined using the QCD sum rule method.

hep-ph↗

arXiv2025

$T_{bc\bar s}$ states in the process $Υ\to D^{-} \bar B^{0} D_s^{+}$

We perform a theoretical study of the decay process $Υ\to D^{-} \bar{B}^{0} D_s^{+}$ in search of the doubly heavy tetraquark states $T_{bc\bar{s}}$ with quark content $bc\bar{s}\bar{d}$. These $T_{bc\bar{s}}$ states are assumed to be dynamically generated molecular states from the S-wave interactions between $\bar{B}_s^{(*)0} D^{(*)+}$ and $\bar{B}^{(*)0} D_s^{(*)+}$ meson pairs. Based on the total angular momentum and the type of the constituent mesons (pseudoscalars $P$ or vectors $V$), they are labeled as $T_{bc\bar{s}}^{0, PP}$, $T_{bc\bar{s}}^{0, VV}$, and $T_{bc\bar{s}}^{2, VV}$, respectively. The $\bar{B}^{0} D_s^{+}$ invariant mass distribution for this decay is calculated using current algebra, incorporating contributions from $T_{bc\bar{s}}$ states arising from final-state interactions. Our results reveal a clear peak structure in the $7415 - 7425$ MeV region, which is attributed to the $T_{bc\bar{s}}^{2, VV}$ state. Additionally, a distinct dip structure appears near the $\bar{B}^{*0} D_s^{*+}$ threshold, characteristic of the $T_{bc\bar{s}}^{2, VV}$ as a hadronic molecular state. A near-threshold enhancement associated with the $T_{bc\bar{s}}^{0, PP}$ state and a dip arising from the $T_{bc\bar{s}}^{0,\,VV}$ state are also identified, though the manifestation of these features depends sensitively on model parameter fine-tuning. Therefore, with increased experimental statistics, the decay channel $Υ\to D^{-} \bar{B}^{0} D_s^{+}$ offers a promising avenue for discovering and characterizing the $T_{bc\bar{s}}$ states.

hep-ph↗

arXiv2025

Fully-heavy hadronic molecules $B_c^{()+} B_c^{()-}$ bound by fully-heavy mesons

A lot of exotic hadrons were reported in the past twenty years, which bring us the renaissance of the hadron spectroscopy. Most of them can be understood as hadronic molecules, whose interactions are mainly due to the exchange of light mesons, and specifically, light vector mesons through the coupled-channel unitary approach within the local hidden-gauge formalism. It is still controversial whether the interaction arising from the exchange of heavy mesons is capable of forming hadronic molecules. We apply the coupled-channel unitary approach to study the fully-heavy $b \bar b c \bar c$ system, where the exchanged mesons can only be the fully-heavy vector mesons $J/ψ$, $B_c^*$, and $Υ$. Especially, the $J/ψ$ meson is much lighter than the $B_c^{(*)}$ mesons, so the present study can be taken as a general investigation on the question whether a lower-mass fully-heavy meson is able to bind two higher-mass fully-heavy hadrons. Our results suggest the existence of the fully-heavy hadronic molecules $|B_c^{+} B_c^{-}; J^{PC}=0^{++} \rangle$, $|B_c^{*+} B_c^{-} - c.c.; J^{PC}=1^{+-} \rangle$, and $|B_c^{*+} B_c^{*-}; J^{PC}=2^{++} \rangle$ as well as the possible existence of $|B_c^{*+} B_c^{-} + c.c.; J^{PC}=1^{++} \rangle$. These states are potentially to be observed in the $μ^+ μ^- J/ψ$ and $μ^+ μ^- Υ$ channels in future ATLAS, CMS, and LHCb experiments.

hep-ph↗

arXiv2025

Hadronic molecules with four charm or beauty quarks

We apply the extended local hidden gauge formalism to study the meson-meson interactions with the quark constituents $cc\bar c\bar c$, $cc\bar c\bar b/\bar c\bar c cb$, $cc\bar b\bar b/\bar c\bar c bb$, $bb\bar c\bar b/\bar b\bar b cb$, and $bb\bar b\bar b$, where the exchanged mesons are the fully-heavy vector mesons $J/ψ$, $B_c^*$, and $Υ$. We solve the coupled-channel Bethe-Salpeter equation to derive two poles in the $bb\bar{c}\bar{b}$ system and two poles in the $cc\bar{c}\bar{b}$ system. There are also four charge-conjugated poles in the $\bar{b}\bar{b}cb$ and $\bar{c}\bar{c}cb$ systems. In the $bb\bar{c}\bar{b}$ system, one pole corresponds to a sub-threshold bound state when the cutoff momentum is set to $Λ> 850$ MeV. The other pole in this system corresponds to a sub-threshold bound state when $Λ> 1100$ MeV. In the $cc\bar{c}\bar{b}$ system, the two poles correspond to sub-threshold bound states only when $Λ> 1550$ MeV and $Λ> 2650$ MeV. This makes them difficult to identify as deeply-bound hadronic molecules. We propose investigating the two poles of the $bb\bar{c}\bar{b}$ system in the $ μ^+μ^-B_c^-$channel at the LHC.

hep-ph↗

arXiv2024

Molecular pentaquark states with open charm and bottom flavors

We study the possibly-existing molecular pentaquark states with open charm and bottom flavors, {\it i.e.}, the states with the quark contents $c\bar{b}qqq$ and $b\bar{c}qqq$ ($q=u,d,s$). We investigate the meson-baryon interactions through the coupled-channel unitary approach within the local hidden-gauge formalism, and extract the poles by solving the Bethe-Salpeter equation in coupled channels. These poles qualify as molecular pentaquark states, which are dynamically generated from the meson-baryon interactions through the exchange of vector mesons. Our results suggest the existence of the $Σ_c^{(*)} B^{(*)}$ and $Σ_b^{(*)} \bar{D}^{(*)}$ molecular states with isospin $I=1/2$, the $Ξ_c^{(\prime,*)} B^{(*)}$ and $Ξ_b^{(\prime,*)} \bar{D}^{(*)}$ molecular states with isospin $I=0$ and $I=1$, as well as the $Ω_c^{(*)} B^{(*)}$ and $Ω_b^{(*)} \bar D^{(*)}$ molecular states with isospin $I=1/2$.

hep-ph↗

arXiv2023

Hadronic molecular states with the quark contents $bc\bar{s}\bar{q}$, $b\bar{c}s\bar{q}$, and $b\bar{c}\bar{s}q$

We study the hadronic molecular states with the quark content $bc\bar{s}\bar{q}$ by investigating the interactions of the $\bar{B}_s D$, $\bar{B} D_s$, $\bar{B}_s^* D$, $\bar{B}^* D_s$, $\bar{B}_s D^*$, $\bar{B} D_s^*$, $\bar{B}_s^* D^*$, and $\bar{B}^* D_s^*$ systems. By solving the Bethe-Salpeter equation within the extended local hidden gauge formalism, we find altogether six poles qualifying as possible hadronic molecular states: one pole of $J^P=0^+$ below the $\bar{B}_s D$-$\bar{B}D_s$ threshold, one pole of $J^P=1^+$ below the $\bar{B}_s^* D$-$\bar{B}^* D_s$ threshold, one pole of $J^P=1^+$ below the $\bar{B}_s D^*$-$\bar{B}D_s^*$ threshold, and three poles of $J^P=0^+/1^+/2^+$ below the $\bar{B}_s^* D^*$-$\bar{B}^* D_s^*$ threshold. Their binding energies are calculated to be about 10-20 MeV with the cut-off momentum $q_\textrm{max}=600\textrm{ MeV}$. Similarly, we study the hadronic molecular states with $bs\bar{c}\bar{q}$ by investigating the interactions of the $\bar{B}\bar{D}_s$, $\bar{B}_c\bar{K}$, $\bar{B}^*\bar{D}_s$, $\bar{B}_c^*\bar{K}$, $\bar{B}\bar{D}_s^*$, $\bar{B}_c\bar{K}^*$, $\bar{B}^*\bar{D}_s^*$, $\bar{B}_c^*\bar{K}^*$ systems, and the states with $bq\bar{c}\bar{s}$ by investigating the interactions of the $\bar{B}_s\bar{D}$, $\bar{B}_cK$, $\bar{B}_s^*\bar{D}$, $\bar{B}_c^*K$, $\bar{B}_s\bar{D}^*$, $\bar{B}_cK^*$, $\bar{B}_s^*\bar{D}^*$, $\bar{B}_c^*K^*$ systems. However, no deeply-bound poles are found in these systems.

hep-ph↗

arXiv2021

The resonances $X(4140)$, $X(4160)$, and $P_{cs}(4459)$ in the decay of $Λ_b\to J/ψΛϕ$

We study the decay of $Λ_b\to J/ψΛϕ$ by taking into account the intermediate resonances $X(4140)$, $X(4160)$, and $P_{cs}(4459)$. In addition to the peak of the $X(4140)$, we also find a bump structure around 4160 MeV followed by a cusp structure around $D^*_s\bar{D}^*_s$ threshold in the $J/ψϕ$ invariant mass distribution of the $Λ_b\to J/ψΛϕ$ process, which can be associated to the $D^*_s\bar{D}^*_s$ molecular state $X(4160)$. We also show that this reaction can also be used to confirm the existence of the hidden-charm pentaquark $P_{cs}(4459)$ with strangeness. We predict an enhancement structure close to the threshold in the $D^*_s\bar{D}^*_s$ invariant mass distribution of the $Λ_b\to D^*_s\bar{D}^*_sΛ$ process, which is the reflection of the $X(4160)$ and should not be misidentified with a new resonance. We strongly suggest experimentalists to further measure these processes, which can be useful to clarify the nature of $X(4140)$ and $X(4160)$ resonances, and to confirm the existence of the $P_{cs}(4459)$.

hep-ph↗