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Description of the newly observed Ωc\Omega^{*}_{c} states as molecular states

Jingwen Feng School of Physics and Electronic Engineering, Sichuan Normal University, Chengdu 610101, China    Feng Yang School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031,China    Cai Cheng [email protected] School of Physics and Electronic Engineering, Sichuan Normal University, Chengdu 610101, China    Yin Huang [email protected] School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031,China
Abstract

In this work, we study the strong decays of the newly observed Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327) assuming that Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327) as SS-wave DΞD\Xi and DΞD^{*}\Xi molecular state, respectively. Since the Ωc\Omega_{c}^{*} was observed in the Ξc+K\Xi_{c}^{+}K^{-} invariant mass distributions, the partial decay width of Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327) into Ξc+K\Xi_{c}^{+}K^{-} through hadronic loops are evaluated with the help of the effective Lagrangians. Moreover, the decay channel of ΞcK¯\Xi_{c}^{{}^{\prime}}\bar{K} is also included. The decay process is described by the tt-channel Λ\Lambda, Σ\Sigma baryons and DsD_{s}, DsD_{s}^{*} mesons exchanges, respectively. By comparison with the LHCb observation, the current results support the Ωc(3327)\Omega^{*}_{c}(3327) withJP=3/2J^{P}=3/2^{-} as pure DΞD^{*}\Xi molecule while the Ωc(3327)\Omega^{*}_{c}(3327) with JP=1/2J^{P}=1/2^{-} can not be well reproduced in the molecular state picture. In addition, the spin-parity JP=1/2J^{P}=1/2^{-} DΞD\Xi molecular assumptions for the Ωc(3185)\Omega^{*}_{c}(3185) can’t be conclusively determined. It may be a meson-baryon molecule with a big DΞD\Xi component. Although the decay width of the ΩcK¯Ξc\Omega_{c}^{*}\to{}\bar{K}\Xi_{c}^{{}^{\prime}} is of the order several MeV, it can be well employed to test the molecule interpretations of Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327).

I Introduction

After the discovery of the five Ωc\Omega^{*}_{c} states in one observation simultaneously back in 2017 LHCb:2017uwr , the latest experimental results of the LHCb Collaboration reported the existence of an additional two Ωc\Omega_{c} states in the Ξc+K\Xi_{c}^{+}K^{-} invariant mass spectrum, originating from pppp collisions LHCb:2023rtu . The measured parameters of these newly states are as follows:

MΩc(3185)\displaystyle M_{\Omega_{c}(3185)} =3185.1±1.70.9+7.4±0.2MeV,\displaystyle=3185.1\pm{}1.7^{+7.4}_{-0.9}\pm{}0.2~{}~{}~{}~{}~{}{\rm MeV},
ΓΩc(3185)\displaystyle\Gamma_{\Omega_{c}(3185)} =50±720+10MeV,\displaystyle=50\pm 7^{+10}_{-20}~{}~{}~{}~{}~{}{\rm MeV}, (1)
MΩc(3327)\displaystyle M_{\Omega_{c}(3327)} =3327.1±1.21.3+0.1±0.2MeV,\displaystyle=3327.1\pm{}1.2^{+0.1}_{-1.3}\pm{}0.2~{}~{}~{}~{}~{}{\rm MeV},
ΓΩc(3327)\displaystyle\Gamma_{\Omega_{c}(3327)} =20±51+13MeV.\displaystyle=20\pm 5^{+13}_{-1}~{}~{}~{}~{}~{}{\rm MeV}.

Compared to the earlier discovery of two ground states Ωc(2695)\Omega^{*}_{c}(2695) and Ωc(2770)\Omega^{*}_{c}(2770) Workman:2022ynf , the findings presented in not only expand our understanding of the charmed baryon with quantum numbers C=1C=1 and S=2S=2, which is composed of one charm quark and two strange quarks, but also help us to strange quarks, but also help us to understand the formation mechanism of exotic hadron states. This is mainly because the newly observed Ωc\Omega^{*}_{c} states may display a more complex internal structure than the ground states Ωc(2695)\Omega^{*}_{c}(2695) and Ωc(2770)\Omega^{*}_{c}(2770), which are made up of three quarks.

Indeed, the Ωc(3050)\Omega^{*}_{c}(3050) and Ωc(3119)\Omega_{c}^{*}(3119) were suggested to be the exotic pentaquarks in the chiral quark-soliton model Kim:2017jpx ; Kim:2017khv . Similar qualitative results can also be found in Refs. Yang:2017rpg ; An:2017lwg . In Refs. Debastiani:2017ewu ; Montana:2017kjw , based on the analysis of the mass spectrum, the Ωc(3050)\Omega^{*}_{c}(3050) was identified as a meson-baryon molecule with JP=1/2J^{P}=1/2^{-}. This is the same with the results in Ref. Huang:2018wgr that the total decay widths of the Ωc(3050)\Omega^{*}_{c}(3050) can be well reproduced with the assumption that Ωc(3050)\Omega^{*}_{c}(3050) as SS-wave ΞD\Xi{}D bound state with JP=1/2J^{P}=1/2^{-}. By solving a coupled-channel Bethe Salpeter equation using a SU(6)lsf×SU(6)_{lsf}\times HQSS extended WT interaction as a kernel, three meson-baryon molecular states were obtained Nieves:2017jjx that can be associated to the experimental states Ωc(3000)\Omega^{*}_{c}(3000), Ωc(3050)\Omega^{*}_{c}(3050), and Ωc(31119)\Omega^{*}_{c}(31119) or Ωc(3090)\Omega^{*}_{c}(3090).

There also exist some clues support the newly observed Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3227)\Omega^{*}_{c}(3227) as molecular states. It was suggested in Ref. Yu:2023bxn that Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327) were proposed to be the 2S(3/2+)2S(3/2^{+}) and 1D(3/2+)1D(3/2^{+}) states, respectively. However, a completely different conclusion was drawn from Ref. luo:2023bxn that the Ωc(3327)\Omega^{*}_{c}(3327) is a good candidate of Ωc(1D)\Omega^{*}_{c}(1D) state with JP=5/2+J^{P}=5/2^{+}. There exists spin-parity puzzle for Ωc(3327)\Omega^{*}_{c}(3327) indicate it difficult to put Ωc(3327)\Omega^{*}_{c}(3327) into the conventional csscss states. Since the mass of Ωc(3327)\Omega^{*}_{c}(3327) is very close to the threshold of DΞD^{*}\Xi, the hadronic molecular configuration for Ωc(3327)\Omega^{*}_{c}(3327) is possible. Although the Ωc(3185)\Omega^{*}_{c}(3185) can be considered as a conventional charmed baryon Yu:2023bxn , the hadronic molecule interpretations cannot be excluded due to the mass of Ωc(3185)\Omega^{*}_{c}(3185) is about 6.37 MeV below the threshold of DΞD\Xi.

However, no work has been conducted to study whether the newly observed Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327) can be explained as DΞD\Xi and DΞD^{*}\Xi molecular state, respectively. In this work, we estimate possible strong decay modes by assuming Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327) as molecular states. By comparing the calculated decay widths with experimental data, we can evaluate the validity of the proposed molecular explanations for the structures of Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327).

This paper is organized as follows. In Sec. II, we will present the theoretical formalism. In Sec. III, the numerical result will be given, followed by discussions and conclusions in last section.

II FORMALISM AND INGREDIENTS

Refer to caption
Figure 1: Feynman diagrams for the process Ωc0(3185,3327)KΞc+\Omega^{0}_{c}(3185,3327)\to{}K^{-}\Xi^{+}_{c} and KΞc+K^{-}\Xi^{{}^{\prime}+}_{c}.

With assuming the newly observed Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3227)\Omega^{*}_{c}(3227) as SS-wave molecular states, the decay of Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3227)\Omega^{*}_{c}(3227) into K¯Ξc\bar{K}\Xi_{c} and K¯Ξc\bar{K}\Xi_{c}^{{}^{\prime}} are allowed. The corresponding Feynman diagrams are illustrated in Fig. 1, which includes the tt-channel Σ\Sigma, Λ\Lambda baryons exchange and DsD_{s}, DsD_{s}^{*} mesons exchange. To evaluate these diagrams, the Lagrangian for the coupling between the mesons and the baryons are obtained using the SU(4)SU(4) invariant interaction Lagrangians Liu:2001ce

PBB\displaystyle\mathcal{L}_{PBB} =igp(aϕαννγ5Pαβϕβμν+bϕαμνγ5Pαβϕβμν),\displaystyle=ig_{p}(a\phi^{*\alpha\nu\nu}\gamma^{5}P^{\beta}_{\alpha}\phi_{\beta\mu\nu}+b\phi^{*\alpha\mu\nu}\gamma^{5}P^{\beta}_{\alpha}\phi_{\beta\mu\nu}), (2)
VBB\displaystyle\mathcal{L}_{VBB} =igv(cϕαννγPαβϕβμν+dϕαννγPαβϕβμν),\displaystyle=ig_{v}(c\phi^{*\alpha\nu\nu}\gamma P^{\beta}_{\alpha}\phi_{\beta\mu\nu}+d\phi^{*\alpha\nu\nu}\gamma P^{\beta}_{\alpha}\phi_{\beta\mu\nu}),

where VμV_{\mu} and PP are the SU(4)SU(4) vector meson and pseudoscalar meson matrix, respectively. The meson matrices are

P=(π02+η6+ηc12π+K+D¯0ππ02+η6+ηc12K0DKK¯02η6+ηc12DsD0D+Ds+3ηc12)\displaystyle P=\begin{pmatrix}\frac{\pi^{0}}{\sqrt{2}}+\frac{\eta}{\sqrt{6}}+\frac{\eta_{c}}{\sqrt{12}}&\pi^{+}&K^{+}&\bar{D}^{0}\\ \pi^{-}&-\frac{\pi^{0}}{\sqrt{2}}+\frac{\eta}{\sqrt{6}}+\frac{\eta_{c}}{\sqrt{12}}&K^{0}&D^{-}\\ K^{-}&\bar{K}^{0}&-\frac{2\eta}{\sqrt{6}}+\frac{\eta_{c}}{\sqrt{12}}&D_{s}^{-}\\ D^{0}&D^{+}&D_{s}^{+}&-\frac{3\eta_{c}}{\sqrt{12}}\end{pmatrix} (3)

and

V=(ρ02+ω86+J/Ψ12ρ+K+D¯0ρρ02+ω86+J/Ψ12K0DKK¯02ω86+J/Ψ12DsD0D+Ds+3J/Ψ12).\displaystyle V=\begin{pmatrix}\frac{\rho^{0}}{\sqrt{2}}+\frac{\omega_{8}}{\sqrt{6}}+\frac{J/\Psi}{\sqrt{12}}&\rho^{+}&K^{*+}&\bar{D}^{*0}\\ \rho^{-}&-\frac{\rho^{0}}{\sqrt{2}}+\frac{\omega_{8}}{\sqrt{6}}+\frac{J/\Psi}{\sqrt{12}}&K^{*0}&D^{*-}\\ K^{*-}&\bar{K}^{*0}&-\frac{2\omega_{8}}{\sqrt{6}}+\frac{J/\Psi}{\sqrt{12}}&D_{s}^{*-}\\ D^{*0}&D^{*+}&D_{s}^{*+}&-\frac{3J/\Psi}{\sqrt{12}}\end{pmatrix}. (4)

with ω8=ωcosθ+ϕsinθ\omega_{8}=\omega\cos\theta+\phi\sin\theta and sinθ=0.761\sin\theta=-0.761. The tensors ϕβμν\phi_{\beta\mu\nu} in above equation represents 20-plet of the proton Liu:2001ce ,

p=ϕ112,n=ϕ221,Λ=23(ϕ321ϕ312),\displaystyle p=\phi_{112},n=\phi_{221},\Lambda=\sqrt{\frac{2}{3}}(\phi_{321}-\phi_{312}),
Σ+=ϕ113,Σ0=2ϕ123,Σ=ϕ233,\displaystyle\Sigma^{+}=\phi_{113},\Sigma^{0}=\sqrt{2}\phi_{123},\Sigma^{-}=\phi_{233},
Ξ0=ϕ311,Ξ=ϕ332,Σc++=ϕ114,\displaystyle\Xi^{0}=\phi_{311},\Xi^{-}=\phi_{332},\Sigma^{++}_{c}=\phi_{114},
Σc+=ϕ124,Σc0=ϕ224,Ξc+=ϕ134,\displaystyle\Sigma^{+}_{c}=\phi_{124},\Sigma^{0}_{c}=\phi_{224},\Xi_{c}^{+}=\phi_{134},
Ξc0=ϕ234,Ξc+=23(ϕ413ϕ431),Ξc0=23(ϕ423ϕ432)\displaystyle\Xi_{c}^{0}=\phi_{234},\Xi_{c}^{+^{\prime}}=\sqrt{\frac{2}{3}}(\phi_{413}-\phi_{431}),\Xi_{c}^{0^{\prime}}=\sqrt{\frac{2}{3}}(\phi_{423}-\phi_{432})
Λc+=23(ϕ421ϕ412),Ωc0=ϕ334,Ξcc++=ϕ441\displaystyle\Lambda_{c}^{+}=\sqrt{\frac{2}{3}}(\phi_{421}-\phi_{412}),\Omega_{c}^{0}=\phi_{334},\Xi^{++}_{cc}=\phi_{441}
Ξcc+=ϕ442,Ωcc+=ϕ443,\displaystyle\Xi_{cc}^{+}=\phi_{442},\Omega_{cc}^{+}=\phi_{443}, (5)

where the indices β\beta, μ\mu, ν\nu denote the quark content of the baryon fields with the identification 1u1\leftrightarrow{}u, 2d2\leftrightarrow{}d, 3s3\leftrightarrow{}s, and 4c4\leftrightarrow{}c. Hence, the tensors ϕβμν\phi_{\beta\mu\nu} satisfy following condition

ϕμνλ+ϕνλμ+ϕλμν=0,ϕμνλ=ϕνμλ.\displaystyle\phi_{\mu\nu\lambda}+\phi_{\nu\lambda\mu}+\phi_{\lambda\mu\nu}=0,\phi_{\mu\nu\lambda}=\phi_{\nu\mu\lambda}. (6)

By using the exact form of the matrix and the above relationship, the interaction vertices between baryons and pseudoscalar mesons can be estimated by expanding the SU(4) invariant interaction Lagrangians. The values of the coupling constants adopted in this work can be computed by comparing with the coefficients of the interaction Lagrangians πNN{\cal{L}}_{\pi{}NN} and ρNN{\cal{L}}_{\rho{}NN} and determining the constants gVg_{V}, gPg_{P}, aa, bb, cc, and dd in terms of gπNN=13.5g_{\pi{}NN}=13.5 and gρNN=3.25g_{\rho{}NN}=3.25 Liu:2001ce . Then the values of the coupling constants can be compute and are listed in Tab. 1.

Table 1: Values of the effective couplings constants.
gΞc+D+Σ0g_{\Xi_{c}^{+}D^{+}\Sigma^{0}} gΞKΣ0g_{\Xi^{-}K^{-}\Sigma^{0}} gD+Ξc+Λ0g_{D^{+}\Xi_{c}^{+}\Lambda^{0}} gΞKΛ0g_{\Xi^{-}K^{-}\Lambda^{0}} gD0Ξc+Σ+g_{D^{0}\Xi_{c}^{+}\Sigma^{+}} gΞ0Σ+Kg_{\Xi^{0}\Sigma^{+}K^{-}} gΞ0DsΞc+g_{\Xi^{0}D^{*-}_{s}\Xi_{c}^{+}}
3.78 13.5 6.55 3.43 5.35 -19.09 4.60
gD+Σ0Ξc+g_{D^{*+}\Sigma^{0}\Xi_{c}^{+}} gD+Λ0Ξc+g_{D^{*+}\Lambda^{0}\Xi_{c}^{+}} gD0Σ+Ξc+g_{D^{*0}\Sigma^{+}\Xi_{c}^{+}} gΞ0DsΞc+g_{\Xi^{0}D_{s}^{-}\Xi_{c}^{+}} gD+Σ0Ξc+g_{D^{+}\Sigma^{0}\Xi_{c}^{{}^{\prime}+}} gD+Λ0Ξc+g_{D^{+}\Lambda^{0}\Xi_{c}^{{}^{\prime}+}} gD0Σ+Ξc+g_{D^{0}\Sigma^{+}\Xi_{c}^{{}^{\prime}+}}
3.25 -5.63 -4.60 5.35 9.48 5.47 13.41
gΞc+DsΞ0g_{\Xi_{c}^{{}^{\prime}+}D^{*-}_{s}\Xi^{0}} gD+Σ0Ξc+g_{D^{*+}\Sigma^{0}\Xi_{c}^{{}^{\prime}+}} gD+Λ0Ξc+g_{D^{*+}\Lambda^{0}\Xi_{c}^{{}^{\prime}+}} gD0Σ+Ξc+g_{D^{*0}\Sigma^{+}\Xi_{c}^{{}^{\prime}+}} gΞ0DsΞc+g_{\Xi^{0}D_{s}^{-}\Xi_{c}^{{}^{\prime}+}} gD0DsKg_{D^{*0}D^{-}_{s}K^{-}} gD0DsKg_{D^{0}D^{*-}_{s}K^{-}}
-5.63 3.98 -2.30 5.63 -13.40 12.00 12.00

In addition to the Lagrangian shown in Eq.2, the effective Lagrangians of relevant interaction vertices are also needed Yang:2021pio

PPV\displaystyle\mathcal{L}_{PPV} =iG22μP(PVμVμP),\displaystyle=\frac{iG}{2\sqrt{2}}\langle\partial^{\mu}P(PV_{\mu}-V_{\mu}P)\rangle, (7)
VVP\displaystyle\mathcal{L}_{VVP} =G2ϵμναβμVναVβP,\displaystyle=\frac{G^{\prime}}{\sqrt{2}}\epsilon^{\mu\nu\alpha\beta}\langle\partial_{\mu}V_{\nu}\partial_{\alpha}V_{\beta}P\rangle, (8)
VVV\displaystyle\mathcal{L}_{VVV} =iG22μVν(VμVνVνVμ),\displaystyle=\frac{iG}{2\sqrt{2}}\langle\partial^{\mu}V^{\nu}(V_{\mu}V_{\nu}-V_{\nu}V_{\mu})\rangle, (9)

where the coupling constants G=12.0G=12.0 and G=55.51G^{{}^{\prime}}=55.51 Yang:2021pio .

Since the Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3227)\Omega^{*}_{c}(3227) states are considered as SS-wave bound states of D()ΞD^{(*)}\Xi, the couplings of Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3227)\Omega^{*}_{c}(3227) to their components are written as

Ωc(3185)1/2\displaystyle{\cal{L}}^{1/2^{-}}_{\Omega^{*}_{c}(3185)} =j=ΞD+,Ξ0D0CjgΩc(3185)ΞD1/2Ωc(3185)(x)\displaystyle=\sum_{j=\Xi^{-}D^{+},\Xi^{0}D^{0}}C_{j}g^{1/2^{-}}_{\Omega_{c}(3185)\Xi D}\Omega_{c}(3185)(x)
×dyΦ(y2)Ξ(x+ωDy)D(xωΞy),\displaystyle\times\int dy\Phi(y^{2})\Xi(x+\omega_{D}y)D(x-\omega_{\Xi}y),
Ωc(3327)1/2=\displaystyle{\cal{L}}^{1/2^{-}}_{\Omega^{*}_{c}(3327)}= j=ΞD+,Ξ0D0CjgΩc(3327)ΞD1/2Ωc(3327)(x)γμγ5\displaystyle\sum_{j=\Xi^{-}D^{*+},\Xi^{0}D^{*0}}C_{j}g^{1/2^{-}}_{\Omega^{*}_{c}(3327)\Xi D^{*}}\Omega^{*}_{c}(3327)(x)\gamma^{\mu}\gamma^{5}
×dyΦ(y2)Ξ(x+ωDy)Dμ(xωΞy),\displaystyle\times\int dy\Phi(y^{2})\Xi(x+\omega_{D^{*}}y)D^{*}_{\mu}(x-\omega_{\Xi}y),
Ωc(3327)3/2=\displaystyle{\cal{L}}^{3/2^{-}}_{\Omega^{*}_{c}(3327)}= ij=ΞD+,Ξ0D0CjgΩc(3327)ΞD3/2Ωc(3327)μ(x)\displaystyle-i\sum_{j=\Xi^{-}D^{*+},\Xi^{0}D^{*0}}C_{j}g^{3/2^{-}}_{\Omega_{c}(3327)\Xi D^{*}}\Omega_{c}(3327)^{\mu}(x)
𝑑yΦ(y2)Ξ(x+ωDy)Dμ(xωΞy),\displaystyle\int dy\Phi(y^{2})\Xi(x+\omega_{D^{*}}y)D^{*}_{\mu}(x-\omega_{\Xi}y), (10)

where ωΞ=mΞ/(mΞ+mD())\omega_{\Xi}=m_{\Xi}/(m_{\Xi}+m_{D^{(*)}}) and ωD()=mD()/(mΞ+mD())\omega_{D^{(*)}}=m_{D^{(*)}}/(m_{\Xi}+m_{D^{(*)}}) with mΞm_{\Xi} and mD()m_{D^{(*)}} are the masses of the Ξ\Xi and D()D^{(*)}, respectively. Cj=1/2C_{j}=1/\sqrt{2} is the isospin coefficient, which is calculated from the following isospin assignments for the Ξ\Xi and D()D^{(*)}

(ΞΞ0)(|12,12|12,+12);(D()+D()0)(|12,+12|12,12).\begin{pmatrix}\Xi^{-}\\ \Xi^{0}\end{pmatrix}\sim\begin{pmatrix}-|\frac{1}{2},-\frac{1}{2}\rangle\\ |\frac{1}{2},+\frac{1}{2}\rangle\end{pmatrix};~{}~{}~{}\begin{pmatrix}D^{(*)+}\\ D^{(*)0}\end{pmatrix}\sim\begin{pmatrix}|\frac{1}{2},+\frac{1}{2}\rangle\\ |\frac{1}{2},-\frac{1}{2}\rangle\end{pmatrix}.

In the above equation, Φ(y2)\Phi(y^{2}) is the effective correlation function and serves the following two roles: 1) it shows the distribution of the components in the hadronic molecule, 2) it has the same role with the form factor that can avoid the Feynman diagram’s ultraviolet divergence. Usually, the correlation function can vanish quickly in the ultraviolet region. Here we choose the Fourier transformation of the correlation function to have a Gaussian form

Φ(pE2)exp(pE2/Λ2),\displaystyle\Phi(-p_{E}^{2})\doteq{}\exp(-p_{E}^{2}/\Lambda^{2}), (11)

where pEp_{E} is the Euclidean Jacobi momentum and the parameter Λ\Lambda is taken as a parameter, which will be discussed later. The coupling constants of gΩc(3185)ΞD1/2g^{1/2^{-}}_{\Omega^{*}_{c}(3185)\Xi D}, gΩc(3327)ΞD1/2g^{1/2^{-}}_{\Omega^{*}_{c}(3327)\Xi D^{*}}, gΩc(3327)ΞD3/2g^{3/2^{-}}_{\Omega^{*}_{c}(3327)\Xi{}D^{*}} appearing in Eq. (10) are given in Eq. (12)

ΣΩc(3185)1/2(k0)=\displaystyle\Sigma^{1/2^{-}}_{\Omega^{*}_{c}(3185)}(k_{0})= (gΩcΞD1/2)20𝑑α0𝑑βjCj𝒴(ωD,mD)\displaystyle(g^{1/2^{-}}_{\Omega_{c}\Xi D})^{2}\int_{0}^{\infty}d\alpha\int_{0}^{\infty}d\beta\sum_{j}C_{j}{\cal{Y}}(\omega_{D},m_{D})
×𝒵(ωD,mD),\displaystyle\times{\cal{Z}}(\omega_{D},m_{D}),
ΣΩc(3327)1/2(k0)=\displaystyle\Sigma^{1/2^{-}}_{\Omega^{*}_{c}(3327)}(k_{0})= (gΩcΞD1/2)20𝑑α0𝑑βjCj𝒴(ωD,mD)\displaystyle(g^{1/2^{-}}_{\Omega_{c}\Xi D^{*}})^{2}\int_{0}^{\infty}d\alpha\int_{0}^{\infty}d\beta\sum_{j}C_{j}{\cal{Y}}(\omega_{D^{*}},m_{D^{*}})
×[2𝒵(ωD,mD)+k03(4ωD2β)38mD2z3\displaystyle\times{}[2{\cal{Z}}(\omega_{D^{*}},m_{D^{*}})+\frac{k^{3}_{0}(-4\omega_{D^{*}}-2\beta)^{3}}{8m^{2}_{D^{*}}z^{3}}
3k0Λ2(4ωD2β)2mD2z2+k03(4ωD2β)4mD2z2\displaystyle-\frac{3k_{0}\Lambda^{2}(-4\omega_{D^{*}}-2\beta)}{2m^{2}_{D^{*}}z^{2}}+\frac{k_{0}^{3}(-4\omega_{D^{*}}-2\beta)}{4m^{2}_{D^{*}}z^{2}}
k02(4ωD2β)2mΞ4mD2z2+k0Λ2mD2z+2Λ2mΞmD2z],\displaystyle-\frac{k^{2}_{0}(-4\omega_{D^{*}}-2\beta)^{2}m_{\Xi}}{4m^{2}_{D^{*}}z^{2}}+\frac{k_{0}\Lambda^{2}}{m^{2}_{D^{*}}z}+\frac{2\Lambda^{2}m_{\Xi}}{m^{2}_{D^{*}}z}],
ΣΩc(3327)T3/2(k0)=\displaystyle\Sigma^{T3/2^{-}}_{\Omega^{*}_{c}(3327)}(k_{0})= gΩcΞD20𝑑α0𝑑βjCj𝒴(ωD,mD)\displaystyle g_{\Omega_{c}\Xi D^{*}}^{2}\int_{0}^{\infty}d\alpha\int_{0}^{\infty}d\beta\sum_{j}C_{j}{\cal{Y}}(\omega_{D^{*}},m_{D^{*}})
×[𝒵(ωD,mD)+k0Λ2(4ωD2β)4mD2z2\displaystyle\times[{\cal{Z}}(\omega_{D^{*}},m_{D^{*}})+\frac{k_{0}\Lambda^{2}(-4\omega_{D^{*}}-2\beta)}{4m^{2}_{D^{*}}z^{2}}
+k0Λ22mD2z+Λ2mΞ2mD2z],\displaystyle+\frac{k_{0}\Lambda^{2}}{2m^{2}_{D^{*}}z}+\frac{\Lambda^{2}m_{\Xi}}{2m^{2}_{D^{*}}z}], (12)

with

𝒴(ωD(),mD())\displaystyle{\cal{Y}}(\omega_{D^{(*)}},m_{D^{(*)}}) =116π2z2exp{1Λ2[2k02ωD2+αmD2\displaystyle=\frac{1}{16\pi^{2}z^{2}}\exp\{-\frac{1}{\Lambda^{2}}[-2k_{0}^{2}\omega_{D}^{2}+\alpha m_{D}^{2}
+β(k02+mΞ2)+(4ωD2β)2k024z]}\displaystyle+\beta(-k_{0}^{2}+m^{2}_{\Xi})+\frac{(-4\omega_{D}-2\beta)^{2}k_{0}^{2}}{4z}]\}
𝒵(ωD(),mD())\displaystyle{\cal{Z}}(\omega_{D^{(*)}},m_{D^{(*)}}) =k0+mΞ+k0(4ωD2β)2z,\displaystyle=k_{0}+m_{\Xi}+\frac{k_{0}(-4\omega_{D}-2\beta)}{2z}, (13)

where Z=2+α+βZ=2+\alpha+\beta and k02=mΩc2k_{0}^{2}=m^{2}_{\Omega^{*}_{c}} with k0k_{0}, mΩcm_{\Omega^{*}_{c}} are the four momenta and the mass of the newly observed Ωc\Omega^{*}_{c}, respectively. If the Ωc\Omega_{c}^{*} is a D()ΞD^{(*)}\Xi molecular states with JP=1/2J^{P}=1/2^{-}, the Σ1/2\Sigma^{1/2^{-}} is the self-energy operator of the hadronic molecule Ωc\Omega_{c}^{*}. However, ΣT3/2\Sigma^{T3/2^{-}} is the transverse part of the self-energy operator ΣΩcμν\Sigma^{\mu\nu}_{\Omega_{c}^{*}} when we assuming Ωc\Omega_{c}^{*} as D()ΞD^{(*)}\Xi molecular states with JP=3/2J^{P}=3/2^{-}. Once the self-energy operator and its transverse part are obtained, the coupling constants of the hadronic molecule Ωc\Omega_{c}^{*} to its constituents D()ΞD^{(*)}\Xi can be determined using the compositeness condition based on the work in Ref. Weinberg:1962hj . This condition requires that the renormalization constant of the hadronic molecular wave function is equal to zero

1dΣΩc(3185/3327)dk0=0,J=12\displaystyle 1-\frac{d\Sigma_{\Omega^{*}_{c}(3185/3327)}}{dk_{0}}=0,~{}~{}~{}~{}~{}J=\frac{1}{2}
1dΣΩc(3327)Tdk0=0.J=32\displaystyle 1-\frac{d\Sigma^{T}_{\Omega^{*}_{c}(3327)}}{dk_{0}}=0.~{}~{}~{}~{}~{}~{}~{}~{}~{}~{}~{}~{}~{}J=\frac{3}{2} (14)

With the above prepared, we can obtain the general expressions of the amplitudes corresponding to the Feynman diagrams Fig. 1

a1/2\displaystyle\mathcal{M}_{a}^{1/2^{-}} =μ(p2)[12gΩ11gΞc()+D+Σ0gΞKΣ0d4k1(2π)4\displaystyle=\mu(p_{2})[\frac{1}{\sqrt{2}}g_{\Omega 11}g_{\Xi^{(^{\prime})+}_{c}D^{+}\Sigma^{0}}g_{\Xi^{-}K^{-}\Sigma^{0}}\int\frac{d^{4}k_{1}}{(2\pi)^{4}}
×Φ[(pωD+qωΞ)2]γ5i(k/1+mΣ0)k12mΣ02γ5\displaystyle\times\Phi[(p\omega_{D^{+}}-q\omega_{\Xi^{-}})^{2}]\gamma^{5}\frac{i(k\!\!\!/_{1}+m_{\Sigma^{0}})}{k_{1}^{2}-m_{\Sigma^{0}}^{2}}\gamma^{5}
×i(p/+mΞ)p2mΞ2iq2mD+2+12gΩ11gΞc()+D+Λ0\displaystyle\times\frac{i(p\!\!\!/+m_{\Xi^{-}})}{p^{2}-m_{\Xi^{-}}^{2}}\frac{i}{q^{2}-m_{D^{+}}^{2}}+\frac{1}{\sqrt{2}}g_{\Omega 11}g_{\Xi^{(^{\prime})+}_{c}D^{+}\Lambda^{0}}
×gΞKΛ0d4k1(2π)4Φ[(pωD+qωΞ)2]γ5\displaystyle\times{}g_{\Xi^{-}K^{-}\Lambda^{0}}\int\frac{d^{4}k_{1}}{(2\pi)^{4}}\Phi[(p\omega_{D^{+}}-q\omega_{\Xi^{-}})^{2}]\gamma^{5}
×i(k/1+mΛ0)k12mΛ02γ5i(p/+mΞ)p2mΞ2iq2mD+2]μ(k0),\displaystyle\times\frac{i(k\!\!\!/_{1}+m_{\Lambda^{0}})}{k_{1}^{2}-m_{\Lambda^{0}}^{2}}\gamma^{5}\frac{i(p\!\!\!/+m_{\Xi^{-}})}{p^{2}-m_{\Xi^{-}}^{2}}\frac{i}{q^{2}-m_{D^{+}}^{2}}]\mu(k_{0}), (15)
b1/2\displaystyle\mathcal{M}_{b}^{1/2^{-}} =12gΩ12gD0Ξc()+Σ+gΞ0KΣ+d4k1(2π)4\displaystyle=\frac{1}{\sqrt{2}}g_{\Omega 12}g_{D^{0}\Xi_{c}^{(^{\prime})+}\Sigma^{+}}g_{\Xi^{0}K^{-}\Sigma^{+}}\int\frac{d^{4}k_{1}}{(2\pi)^{4}}
×ϕ[(pωD0qωΞ0)2]μ(p2)γ5i(k/1+mΣ+)k12mΣ+2γ5\displaystyle\times\phi[(p\omega_{D^{0}}-q\omega_{\Xi^{0}})^{2}]\mu(p_{2})\gamma^{5}\frac{i(k\!\!\!/_{1}+m_{\Sigma^{+}})}{k_{1}^{2}-m_{\Sigma^{+}}^{2}}\gamma^{5}
×i(p/+mΞ0)p2mΞ02μ(k0)iq2mD02,\displaystyle\times\frac{i(p\!\!\!/+m_{\Xi^{0}})}{p^{2}-m_{\Xi^{0}}^{2}}\mu(k_{0})\frac{i}{q^{2}-m_{D^{0}}^{2}}, (16)
c1/2\displaystyle\mathcal{M}_{c}^{1/2^{-}} =i12gΩ12gD0DsKgΞ0Ξc()+Dsd4k1(2π)4\displaystyle=i\frac{1}{2}g_{\Omega 12}g_{D^{0}D^{*-}_{s}K^{-}}g_{\Xi^{0}\Xi_{c}^{(^{\prime})+}D^{*-}_{s}}\int\frac{d^{4}k_{1}}{(2\pi)^{4}}
×Φ[(pωD0qωΞ0)2]μ(p2)γνi(gμν+k1μk1νmDs2)k12mDs2\displaystyle\times\Phi[(p\omega_{D^{0}}-q\omega_{\Xi^{0}})^{2}]\mu({p_{2}})\gamma^{\nu}\frac{i(-g^{\mu\nu}+\frac{k_{1}^{\mu}k_{1}^{\nu}}{m_{D^{*-}_{s}}^{2}})}{k^{2}_{1}-m^{2}_{D^{*-}_{s}}}
×(iqμip1μ)iq2mD02μ(k0)i(p/+mΞ0)p2mΞ02,\displaystyle\times(iq^{\mu}-ip_{1}^{\mu})\frac{i}{q^{2}-m_{D^{0}}^{2}}\mu(k_{0})\frac{i(p\!\!\!/+m_{\Xi^{0}})}{p^{2}-m^{2}_{\Xi^{0}}}, (17)
d1/2\displaystyle\mathcal{M}_{d}^{1/2^{-}} =μ(p2)[12gΩ21gΞc()+D+Σ0gΞKΣ0d4k1(2π)4\displaystyle=\mu(p_{2})[\frac{1}{\sqrt{2}}g_{\Omega 21}g_{\Xi^{(^{\prime})+}_{c}D^{*+}\Sigma^{0}}g_{\Xi^{-}K^{-}\Sigma^{0}}\int\frac{d^{4}k_{1}}{(2\pi)^{4}}
×Φ[(pωD+qωΞ)2]γμi(k/1+mΣ0)k12mΣ02γ5\displaystyle\times\Phi[(p\omega_{D^{*+}}-q\omega_{\Xi^{-}})^{2}]\gamma^{\mu}\frac{i(k\!\!\!/_{1}+m_{\Sigma^{0}})}{k_{1}^{2}-m_{\Sigma^{0}}^{2}}\gamma^{5}
×i(p/+mΞ)p2mΞ2γνγ5i(gμν+qμqνmD+2)q2mD+2\displaystyle\times\frac{i(p\!\!\!/+m_{\Xi^{-}})}{p^{2}-m_{\Xi^{-}}^{2}}\gamma^{\nu}\gamma^{5}\frac{i(-g^{\mu\nu}+\frac{q^{\mu}q^{\nu}}{m^{2}_{D^{*+}}})}{q^{2}-m_{D^{*+}}^{2}}
+12gΩ21gΞc()+D+Λ0gΞKΛ0d4k1(2π)4\displaystyle+\frac{1}{\sqrt{2}}g_{\Omega 21}g_{\Xi^{(^{\prime})+}_{c}D^{*+}\Lambda^{0}}g_{\Xi^{-}K^{-}\Lambda^{0}}\int\frac{d^{4}k_{1}}{(2\pi)^{4}}
×Φ[(pωD+qωΞ)2]γαi(k/1+mΛ0)k12mΛ02γ5\displaystyle\times\Phi[(p\omega_{D^{*+}}-q\omega_{\Xi^{-}})^{2}]\gamma^{\alpha}\frac{i(k\!\!\!/_{1}+m_{\Lambda^{0}})}{k_{1}^{2}-m_{\Lambda^{0}}^{2}}\gamma^{5}
×i(p/+mΞ)p2mΞ2γβγ5i(gαβ+qαqβmD+2)q2mD+2]μ(k0),\displaystyle\times\frac{i(p\!\!\!/+m_{\Xi^{-}})}{p^{2}-m_{\Xi^{-}}^{2}}\gamma^{\beta}\gamma^{5}\frac{i(-g^{\alpha\beta}+\frac{q^{\alpha}q^{\beta}}{m^{2}_{D^{*+}}})}{q^{2}-m_{D^{*+}}^{2}}]\mu(k_{0}), (18)
d3/2\displaystyle\mathcal{M}_{d}^{3/2^{-}} =μ(p2)[i12gΩ31gΞc()+D+Σ0gΞKΣ0d4k1(2π)4\displaystyle=\mu(p_{2})[-i\frac{1}{\sqrt{2}}g_{\Omega 31}g_{\Xi^{(^{\prime})+}_{c}D^{*+}\Sigma^{0}}g_{\Xi^{-}K^{-}\Sigma^{0}}\int\frac{d^{4}k_{1}}{(2\pi)^{4}}
×Φ[(pωD+qωΞ)2]γμi(k/1+mΣ0)k12mΣ02γ5\displaystyle\times\Phi[(p\omega_{D^{*+}}-q\omega_{\Xi^{-}})^{2}]\gamma^{\mu}\frac{i({k\!\!\!/_{1}}+m_{\Sigma^{0}})}{k_{1}^{2}-m_{\Sigma^{0}}^{2}}\gamma^{5}
×i(p/+mΞ)p2mΞ2gνλi(gμν+qμqνmD+2)q2mD+2\displaystyle\times\frac{i({p\!\!\!/}+m_{\Xi^{-}})}{p^{2}-m_{\Xi^{-}}^{2}}g^{\nu\lambda}\frac{i(-g^{\mu\nu}+\frac{q^{\mu}q^{\nu}}{m^{2}_{D^{*+}}})}{q^{2}-m_{D^{*+}}^{2}}
i12gΩ31gΞc()+D+Λ0gΞKΛ0d4k1(2π)4\displaystyle-i\frac{1}{\sqrt{2}}g_{\Omega 31}g_{\Xi^{(^{\prime})+}_{c}D^{*+}\Lambda^{0}}g_{\Xi^{-}K^{-}\Lambda^{0}}\int\frac{d^{4}k_{1}}{(2\pi)^{4}}
×Φ[(pωD+qωΞ)2]γαi(k/1+mΛ0)k12mΛ02γ5\displaystyle\times\Phi[(p\omega_{D^{*+}}-q\omega_{\Xi^{-}})^{2}]\gamma^{\alpha}\frac{i({k\!\!\!/_{1}}+m_{\Lambda^{0}})}{k_{1}^{2}-m_{\Lambda^{0}}^{2}}\gamma^{5}
×i(p/+mΞ)p2mΞ2gβλi(gαβ+qαqβmD+2)q2mD+2]μλ(k0),\displaystyle\times\frac{i({p\!\!\!/}+m_{\Xi^{-}})}{p^{2}-m_{\Xi^{-}}^{2}}g^{\beta\lambda}\frac{i(-g^{\alpha\beta}+\frac{q^{\alpha}q^{\beta}}{m^{2}_{D^{*+}}})}{q^{2}-m_{D^{*+}}^{2}}]\mu_{\lambda}(k_{0}), (19)
e1/2\displaystyle\mathcal{M}_{e}^{1/2^{-}} =12gΩ22gΞc()+D0Σ0gΞ0KΣ0d4k1(2π)4\displaystyle=\frac{1}{\sqrt{2}}g_{\Omega 22}g_{\Xi^{(^{\prime})+}_{c}D^{*0}\Sigma^{0}}g_{\Xi^{0}K^{-}\Sigma^{0}}\int\frac{d^{4}k_{1}}{(2\pi)^{4}}
×Φ[(pωD0qωΞ0)2]μ(p2)γμi(k/1+mΣ+)k12mΣ+2γ5\displaystyle\times\Phi[(p\omega_{D^{*0}}-q\omega_{\Xi^{0}})^{2}]\mu(p_{2})\gamma^{\mu}\frac{i({k\!\!\!/_{1}}+m_{\Sigma^{+}})}{k_{1}^{2}-m_{\Sigma^{+}}^{2}}\gamma^{5}
×i(p/+mΞ0)p2mΞ02μ(k0)γνγ5i(gμν+qμqνmD02)q2mD02,\displaystyle\times\frac{i({p\!\!\!/}+m_{\Xi^{0}})}{p^{2}-m_{\Xi^{0}}^{2}}\mu(k_{0})\gamma^{\nu}\gamma^{5}\frac{i(-g^{\mu\nu}+\frac{q^{\mu}q^{\nu}}{m^{2}_{D^{*0}}})}{q^{2}-m_{D^{*0}}^{2}}, (20)
e3/2\displaystyle\mathcal{M}_{e}^{3/2^{-}} =i2gΩ22gΞc()+D0Σ0gΞ0KΣ0d4k1(2π)4\displaystyle=-\frac{i}{\sqrt{2}}g_{\Omega 22}g_{\Xi^{(^{\prime})+}_{c}D^{*0}\Sigma^{0}}g_{\Xi^{0}K^{-}\Sigma^{0}}\int\frac{d^{4}k_{1}}{(2\pi)^{4}}
×Φ[(pωD0qωΞ0)2]μ(p2)γμi(k/1+mΣ+)k12mΣ+2γ5\displaystyle\times\Phi[(p\omega_{D^{*0}}-q\omega_{\Xi^{0}})^{2}]\mu(p_{2})\gamma^{\mu}\frac{i({k\!\!\!/_{1}}+m_{\Sigma^{+}})}{k_{1}^{2}-m_{\Sigma^{+}}^{2}}\gamma^{5}
×i(p/+mΞ0)p2mΞ02μν(k0)i(gμν+qμqνmD02)q2mD02,\displaystyle\times\frac{i({p\!\!\!/}+m_{\Xi^{0}})}{p^{2}-m_{\Xi^{0}}^{2}}\mu^{\nu}(k_{0})\frac{i(-g^{\mu\nu}+\frac{q^{\mu}q^{\nu}}{m^{2}_{D^{*0}}})}{q^{2}-m_{D^{*0}}^{2}}, (21)
f1/2\displaystyle\mathcal{M}_{f}^{1/2^{-}} =i2gΩ31gD0DsKgΞ0DsΞc()+d4k1(2π)4\displaystyle=\frac{i}{2}g_{\Omega 31}g_{D^{*0}D^{-}_{s}K^{-}}g_{\Xi^{0}D_{s}^{-}\Xi_{c}^{(^{\prime})+}}\int\frac{d^{4}k_{1}}{(2\pi)^{4}}
×Φ[(pωD0qωΞ0)2]μ(p2)γ51k12mDs2\displaystyle\times\Phi[(p\omega_{D^{*0}}-q\omega_{\Xi^{0}})^{2}]\mu(p_{2})\gamma^{5}\frac{1}{k_{1}^{2}-m_{D_{s}^{-}}^{2}}
×(p1μk1μ)(gμν+qμqνmD02)q2mD02μ(k0)γν\displaystyle\times(p_{1}^{\mu}-k_{1}^{\mu})\frac{(-g^{\mu\nu}+\frac{q^{\mu}q^{\nu}}{m^{2}_{D^{*0}}})}{q^{2}-m_{D^{*0}}^{2}}\mu(k_{0})\gamma^{\nu}
×γ5(p/+mΞ0)p2mΞ02,\displaystyle\times\gamma^{5}\frac{({p\!\!\!/}+m_{\Xi^{0}})}{p^{2}-m_{\Xi^{0}}^{2}}, (22)
f3/2\displaystyle\mathcal{M}_{f}^{3/2^{-}} =12gΩ32gD0DsKgΞ0DsΞc()+d4k1(2π)4\displaystyle=\frac{1}{2}g_{\Omega 32}g_{D^{*0}D^{-}_{s}K^{-}}g_{\Xi^{0}D_{s}^{-}\Xi_{c}^{(^{\prime})+}}\int\frac{d^{4}k_{1}}{(2\pi)^{4}}
Φ[(pωD0qωΞ0)2]μ(p2)γ51k12mDs2\displaystyle\Phi[(p\omega_{D^{*0}}-q\omega_{\Xi^{0}})^{2}]\mu(p_{2})\gamma^{5}\frac{1}{k_{1}^{2}-m_{D_{s}^{-}}^{2}}
×(p1μk1μ)(gμν+qμqνmD02)q2mD02μν(k0)(p/+mΞ0)p2mΞ02,\displaystyle\times(p_{1}^{\mu}-k_{1}^{\mu})\frac{(-g^{\mu\nu}+\frac{q^{\mu}q^{\nu}}{m^{2}_{D^{*0}}})}{q^{2}-m_{D^{*0}}^{2}}\mu^{\nu}(k_{0})\frac{({p\!\!\!/}+m_{\Xi^{0}})}{p^{2}-m_{\Xi^{0}}^{2}}, (23)

where the p1p_{1}, p2p_{2}, pp, qq, and k1k_{1} are the four momenta of the KK, Ξc()\Xi_{c}^{(^{\prime})}, Ξ\Xi, D()D^{(*)}, and tt-channel exchanged particles, respectively.

Once the amplitudes are determined, the corresponding decay widths can be obtained, which read,

Γ(Ξc)=12J+118π|𝐩1|mΩc22¯,\displaystyle\Gamma(\Xi_{c}^{*}\to)=\frac{1}{2J+1}\frac{1}{8\pi}\frac{|\mathbf{p}_{1}|}{m_{\Omega_{c}^{*2}}}\overline{{\cal{M}}^{2}}, (24)

where JJ is the total angular momentum of the initial state Ωc\Omega_{c}^{*}, the overline indicates the sum over the polarization vectors of final hadrons. Here 𝐩1\mathbf{p}_{1} is the 3-momenta of the decay products in the center of mass frame.

III RESULTS AND DISCUSSIONS

In this work, we study the strong decay pattern of SS-wave D()ΞD^{(*)}\Xi molecular states within the effective Lagrangians approach, and find the relation between the D()ΞD^{(*)}\Xi molecular state and the newly observed Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327) states. If the estimated strong decay width matches well with the LHCb observation, we can judge the molecule explanations for the structure of Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327). To make a reliable prediction for the strong decay width, the parameter Λ\Lambda that affects our accurate calculation must be clarified. Since the Λ\Lambda could not be well determined from first principles, it has to be determined by fitting to the experimental data. We especially hope the value of the Λ\Lambda can be determined within same theoretical framework adopted in this work.

Fortunately, within the same theoretical framework adopted in current work in Ref Dong:2017rmg , the parameter Λ\Lambda was constrained as Λ=0.911.00\Lambda=0.91-1.00 GeV by comparing the sum of the partial decay modes of the η(2225)\eta(2225) and ϕ(2170)\phi(2170) with the total width. We also note that many exotic states can be well considered as molecules with Λ=0.901.10\Lambda=0.90-1.10 GeV, and we refer the reader to review the Refs. Yang:2021pio ; Dong:2008gb ; Huang:2020taj and their reference. Therefore, we take Λ\Lambda in the range of Λ=0.901.10\Lambda=0.90-1.10 GeV to study whether the Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327) can be interpreted as molecule composed of D()ΞD^{(*)}\Xi molecular components.

Refer to caption
Figure 2: Coupling constants for the newly observed Ωc\Omega_{c}^{*} with different spin-parity as a function of the parameter Λ\Lambda.

Considering the Λ\Lambda values adopted in this work, we will first discuss the results of the calculative coupling constants. Substituting Eq. (12) into Eq. (14), the dependence of the coupling constants on the parameter Λ\Lambda is solved. By performing the integration of parameters α\alpha and β\beta from 0 to infinite, the numerical results are presented in Fig. 2, which shows the variation of the coupling constants with respect to the Λ\Lambda in the range of 0.90 to 1.10 GeV. From the results, we can find that the value of the coupling constants decreases with the increase of Λ\Lambda, and they are not very sensitive to the Λ\Lambda. It is important to note that the coupling constant gΩc(3327)ΞDg_{\Omega^{*}_{c}(3327)\Xi{}D^{*}} decreases sharply at a small Λ\Lambda value. Due to the presence of ultraviolet divergences in the calculation, the average value of the molecular mass was used. Here, the divergences originate from the threshold of D0Ξ0D^{0}\Xi^{0} and D0Ξ0D^{*0}\Xi^{0} channels being slightly below the masses of the Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327), respectively.

After obtaining the coupling constants, we compute the partial decay widths for the transitions Ωc(3185)K¯Ξc()\Omega^{*}_{c}(3185)\to{}\bar{K}\Xi^{(^{\prime})}_{c} and Ωc(3327)K¯Ξc()\Omega^{*}_{c}(3327)\to\bar{K}\Xi_{c}^{(^{\prime})}, and plot the results in Fig. 3, which vary with the parameter Λ=0.91.1\Lambda=0.9-1.1 GeV. Note that the partial decay widths in the channels Ωc(3185)KΞc()+\Omega^{*}_{c}(3185)\to{}K^{-}\Xi^{(^{\prime})+}_{c} Ωc(3185)KΞc()+\Omega^{*}_{c}(3185)\to{}K^{-}\Xi^{(^{\prime})+}_{c} and Ωc(3327)KΞc()+\Omega^{*}_{c}(3327)\to{}K^{-}\Xi_{c}^{(^{\prime})+} are only estimated here, and the other channels Ωc(3185)K¯0Ξc()0\Omega^{*}_{c}(3185)\to{}\bar{K}^{0}\Xi^{(^{\prime})0}_{c} and Ωc(3327)K¯0Ξc()0\Omega^{*}_{c}(3327)\to{}\bar{K}^{0}\Xi_{c}^{(^{\prime})0} can be obtained by isospin symmetry. The sum of these partial decay widths gives the total decay width of the Ωc(3185)\Omega^{*}_{c}(3185) or total decay width of the Ωc(3185)\Omega^{*}_{c}(3185) or Ωc(3327)\Omega^{*}_{c}(3327), which are also shown in Fig. 3.

From the results of Fig. 3(a), we can find that the total decay width for the transitions Ωc(3185)K¯Ξc()\Omega^{*}_{c}(3185)\to{}\bar{K}\Xi^{(^{\prime})}_{c} increases with the increase of Λ\Lambda, while it decreases when Λ\Lambda varies from 0.940 to 0.945 GeV. Comparing with the total decay width for the Ωc(3185)KΞc()\Omega^{*}_{c}(3185)\to{K}\Xi_{c}^{(^{\prime})} reactions, we found the line shape for the total decay width of the Ωc(3327)K¯Ξc\Omega^{*}_{c}(3327)\to{}\bar{K}\Xi_{c}^{{}^{\prime}} reactions are very different. To see how different, we take Ωc(3327)\Omega^{*}_{c}(3327) at JP=1/2J^{P}=1/2^{-} case as an example. The obtained total decay width for the Ωc(3327)K¯Ξc\Omega^{*}_{c}(3327)\to{}\bar{K}\Xi_{c}^{{}^{\prime}} reaction decreases, then it begin increases at Λ=0.935\Lambda=0.935 GeV.

Refer to caption
Figure 3: Partial decay widths of the ΩcK¯Ξc\Omega_{c}^{*}\to{}\bar{K}\Xi_{c} (red dash line), ΩcK¯Ξc\Omega_{c}^{*}\to{}\bar{K}\Xi_{c}^{{}^{\prime}} (magenta dash dot line), and the total decay width with different Ωc\Omega_{c}^{*} states depending on the parameter Λ\Lambda. The oycn error bands correspond to the LHCb observed LHCb:2023rtu .

Now, let me give a clear discussion about whether the Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327) can be interpreted as molecules composed of D()ΞD^{(*)}\Xi molecular components. From Fig. 3, we observe that the total decay width for the ΩcJP=1/2(3327)K¯Ξc()\Omega^{J^{P}=1/2^{-}}_{c}(3327)\to\bar{K}\Xi_{c}^{(^{\prime})} and ΩcJP=3/2(3327)K¯Ξc()\Omega^{J^{P}=3/2^{-}}_{c}(3327)\to\bar{K}\Xi_{c}^{(^{\prime})} is estimated to be about 104.39-167.54 MeV and 15.55-21.04 MeV, respectively, where the theoretical value 15.55-21.04 MeV is close to the experimental data 20±51+1320\pm 5^{+13}_{-1}. This suggests if the spin-parity of the Ωc(3327)\Omega^{*}_{c}(3327) is JP=3/2J^{P}=3/2^{-}, the assignment as an SS-wave pure DΞD^{*}\Xi molecular state for the Ωc(3327)\Omega^{*}_{c}(3327) is supported. However, if the Ωc(3327)\Omega^{*}_{c}(3327) has a spin-parity of 1/21/2^{-}, the predicted total decay width is much bigger than the experimental total width, which disfavors such a spin-parity assignment for the Ωc(3327)\Omega^{*}_{c}(3327) in theDΞD^{*}\Xi molecular picture. Moreover, the spin-parity JP=1/2J^{P}=1/2^{-} DΞD\Xi molecular assumptions for the Ωc(3185)\Omega^{*}_{c}(3185) cannot be conclusively determined. This is because the obtained total decay width for the Ωc(3185)\Omega^{*}_{c}(3185) with JP=1/2J^{P}=1/2^{-} DΞD\Xi assignment is comparable with that of the experimental total width in the range of Λ=0.9000.915\Lambda=0.900-0.915 and Λ=0.9450.990\Lambda=0.945-0.990 GeV. It may be a meson-baryon molecule contain a big DΞD\Xi component.

Indeed, there exist several coupled states composed of DΞD\Xi and DΞD^{*}\Xi components Zhu:2022fyb . However, the authors in Ref. Zhu:2022fyb claim that the interaction between D()D^{(*)} meson and Ξ\Xi baryon is not strong enough to form a pure bound state with quantum numbers considered in the current work. A possible reason for this is that the potential kernels they obtained only consider light meson exchanges and do not include the contact term that describes the short distance interaction between the Ξ\Xi and charmed meson.

Fig. 3 also tells us that the decay width of Ωc(3185)\Omega^{*}_{c}(3185) into K¯Ξc\bar{K}\Xi_{c} is about 64.60-82.98 MeV, which almost fully accounts for the total width of Ωc(3185)\Omega_{c}^{*}(3185). In other words, the transition from Ωc(3185)\Omega^{*}_{c}(3185) to K¯Ξc\bar{K}\Xi_{c}, which is the experimental observation channel, provides a dominant contribution to the total decay width. However, the decay width of Ωc(3185)K¯Ξc\Omega_{c}^{*}(3185)\to\bar{K}\Xi_{c} is up to several MeV, which accounts for 9.86%-10.70% of its total width. That means the transition Ωc(3185)K¯Ξc\Omega_{c}^{*}(3185)\to\bar{K}\Xi^{{}^{\prime}}_{c} gives a minor contribution. A possible explanation for this may be that the phase space for the transition Ωc(3185)K¯Ξc\Omega_{c}^{*}(3185)\to\bar{K}\Xi^{{}^{\prime}}_{c} is smaller than that of the Ωc(3185)K¯Ξc\Omega_{c}^{*}(3185)\to\bar{K}\Xi_{c} reaction. The same conclusion can also be drawn for the Ωc(3327)K¯Ξc()\Omega_{c}(3327)\to\bar{K}\Xi_{c}^{(^{\prime})} reactions.

It should be noted that the authors in Ref. Yu:2023bxn only compute the decay widths of Ωc(3185)\Omega_{c}^{*}(3185) and Ωc(33327)\Omega_{c}^{*}(33327) into K¯Ξc\bar{K}\Xi_{c} by assigning Ωc(3185)\Omega_{c}^{*}(3185) and Ωc(3327)\Omega_{c}^{*}(3327) as state 2S(3/2+)2S(3/2^{+}) and 1D(3/2+)1D(3/2^{+}), respectively. The predicted decay widths can reach 78.16 MeV and 25.60 MeV, respectively, which are both larger than the experimental cental value. This suggest that if the newly observed Ωc\Omega_{c}^{*} is conventional three quark state, the transition ΩcK¯Ξc\Omega_{c}^{*}\to\bar{K}\Xi^{{}^{\prime}}_{c} is very small and can be ignored. Thus, we propose the experimental search for Ωc\Omega_{c}^{*} in the ΩcK¯Ξc\Omega_{c}^{*}\to\bar{K}\Xi^{{}^{\prime}}_{c} reaction that offers a nice channel to test the molecular nature of the Ωc(3185)\Omega_{c}^{*}(3185) and Ωc(33327)\Omega_{c}^{*}(33327).

IV Summary

Inspired by the newly observed baryons Ωc(3185)\Omega_{c}^{*}(3185) and Ωc(33327)\Omega_{c}^{*}(33327), the strong decay widths of the ΩcK¯Ξc\Omega_{c}^{*}\to{}\bar{K}\Xi_{c} and ΩcK¯Ξc\Omega_{c}^{*}\to{}\bar{K}\Xi_{c}^{{}^{\prime}} was studied in an effective Lagrangian approach. Our theoretical approach is based on the assuming that the newly observed Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327) can be explained as SS-wave DΞD\Xi and DΞD^{*}\Xi molecular state, respectively. With the D()ΞD^{(*)}\Xi assignment, the partial decay widths of the Ωc(3185)\Omega_{c}^{*}(3185) and Ωc(33327)\Omega_{c}^{*}(33327) into the K¯Ξc()\bar{K}\Xi_{c}^{(^{\prime})} final states through hadronic loop are calculated. The decay process is described by the tt-channel Λ\Lambda, Σ\Sigma baryons and DsD_{s}, DsD_{s}^{*} mesons exchanges, respectively.

The current results support the Ωc(3327)\Omega^{*}_{c}(3327) withJP=3/2J^{P}=3/2^{-} as pure DΞD^{*}\Xi molecule while the Ωc(3327)\Omega^{*}_{c}(3327) with JP=1/2J^{P}=1/2^{-} can not be well reproduced in the molecular state picture. In addition, the spin-parity JP=1/2J^{P}=1/2^{-} DΞD\Xi molecular assumptions for the Ωc(3185)\Omega^{*}_{c}(3185) can’t be conclusively determined. It may be a meson-baryon molecule with a big DΞD\Xi component. We also find that the transition Ωc(3185)K¯Ξc\Omega^{*}_{c}(3185)\to\bar{K}\Xi_{c}, which is the experimental observation channel, provides a dominant contribution to the total decay width while the transition Ωc(3185)K¯Ξc\Omega_{c}^{*}(3185)\to\bar{K}\Xi^{{}^{\prime}}_{c} gives a minor contribution. However, the decay channel ΩcK¯Ξc\Omega_{c}^{*}\to{}\bar{K}\Xi_{c}^{{}^{\prime}} can be well employed to test the molecule interpretations of Ωc(3185)\Omega^{*}_{c}(3185) and Ωc(3327)\Omega^{*}_{c}(3327) by comparing our results with this in Ref. Yu:2023bxn .

Acknowledgments

Yin Huang acknowledges the YST Program of the APCTP and the support from the National Natural Science Foundation of China under Grant No.12005177.

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