Chinese Physics C

2023-6 Contents

2023, 47(6): 1-2.

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Abstract:

Lepton mass correction in partial wave analyses of charmed meson semi-leptonic decays

Han Zhang, Bai-Cian Ke, Yao Yu, En Wang

2023, 47(6): 063101. doi: 10.1088/1674-1137/acc642

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Abstract:
We derive a parameterization formula for the partial wave analyses of charmed meson semi-leptonic decays while considering the effects of lepton mass. Because the proposed super-tau-charm factory will reach a significantly enhanced luminosity and BESIII is collecting new

\begin{document}$ \psi(3770)\to D\bar{D} $\end{document}

data, our results will help improve the measurement precision of future partial wave analyses of charmed meson semi-muonic decays.

Light meson emissions of selected charmonium-like states within compact tetraquark configurations

Ning Li, Hui-Zhen He, Wei Liang, Qi-Fang Lü, Dian-Yong Chen, Yu-Bing Dong

2023, 47(6): 063102. doi: 10.1088/1674-1137/acc648

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Abstract:
We adopt the quark pair creation model to investigate the light meson emissions of several charmonium-like states. The quark pair creation model is applied to four-body systems, and we calculate the pion/kaon emissions of

\begin{document}$ X(4700) $\end{document}

,

\begin{document}$ Z_c(4430) $\end{document}

,

\begin{document}$ Y(4230) $\end{document}

,

\begin{document}$ Y(4360) $\end{document}

,

\begin{document}$ Y(4390) $\end{document}

, and

\begin{document}$ Y(4660) $\end{document}

within compact tetraquark configurations. We find that the pion/kaon decay widths of

\begin{document}$ X(4700) $\end{document}

and

\begin{document}$ Z_c(4430) $\end{document}

are relatively small, whereas the partial decay widths of the resonances

\begin{document}$ Y(4230) $\end{document}

,

\begin{document}$ Y(4360) $\end{document}

,

\begin{document}$ Y(4390) $\end{document}

, and

\begin{document}$ Y(4660) $\end{document}

are significant. We expect that our exploration of these decay behaviors will provide useful information for future experimental searches and theoretical interpretations.

W-boson mass anomaly from a general SU(2)_L scalar multiplet

Jiajun Wu, Da Huang, Chao-Qiang Geng

2023, 47(6): 063103. doi: 10.1088/1674-1137/acc8bf

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Abstract:
We explain the W-boson mass anomaly by introducing an

\begin{document}$S U(2)_L$\end{document}

scalar multiplet with general isospin and hypercharge {in the case without its vacuum expectation value}. It is shown that the dominant contribution from the scalar multiplet to the W-boson mass arises at the one-loop level, which can be expressed in terms of the electroweak (EW) oblique parameters T and S at leading order. We first rederive the general formulae of T and S induced by a scalar multiplet of EW charges, confirming the results in literature. We then study several specific examples of great phenomenological interest by applying these general expressions. As a result, it is found that the model with a scalar multiplet in an

\begin{document}$S U(2)_L$\end{document}

real representation with

\begin{document}$Y=0$\end{document}

cannot generate the required

\begin{document}$M_W$\end{document}

correction because it leads to vanishing values of T and S. However, the cases with scalars in a complex representation under

\begin{document}$S U(2)_L$\end{document}

with a general hypercharge can explain the

\begin{document}$M_W$\end{document}

excess observed by CDF-II owing to nonzero T and S. We further consider the strong constraints from the perturbativity and EW global fit of the precision data and vary the isospin representation and hypercharge of the additional scalar multiplet to assess the extent of the model to solve the W-boson mass anomaly. It turns out that these constraints play important roles in setting limits on the model parameter space. We also briefly describe the collider signatures of the extra scalar multiplet, especially when it contains long-lived, heavy, highly charged states.

Further study of ${{\boldsymbol{\Omega^*}} \boldsymbol{|1P_{\bf 3/2^-}\rangle} }$ within a chiral quark model

Hui-Hua Zhong, Ru-Hui Ni, Mu-Yang Chen, Xian-Hui Zhong, Ju-Jun Xie

2023, 47(6): 063104. doi: 10.1088/1674-1137/acc9a2

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Abstract:
In our previous studies, we analyzed the two-body strong decays of the low-lying Ω baryon states within a chiral quark model. The results showed that the mass, total width, and two body decay

\begin{document}$ \Omega(2012) \to \bar{K}\Xi $\end{document}

could be well reproduced with the spin-parity

\begin{document}$ J^P=3/2^- $\end{document}

state

\begin{document}$ \Omega^*|1P_{3/2^-}\rangle $\end{document}

classified in the quark model. Stimulated by the new observations of the three-body decay process

\begin{document}$ \Omega(2012)^-\to \Xi^*(1530)^0K^-\to \Xi^-\pi^+K^- $\end{document}

at Belle, in the present study, we further investigate the three-body strong decay

\begin{document}$ \Omega^*|1P_{3/2^-}\rangle \to \Xi^*(1530)\bar{K} \to \Xi\pi\bar{K} $\end{document}

within the chiral quark model. It is found that the

\begin{document}$ \Omega^*|1P_{3/2^-}\rangle $\end{document}

has a sizeable decay rate into the three-body final states

\begin{document}$ \Xi\pi\bar{K} $\end{document}

. When considering

\begin{document}$ \Omega^*|1P_{3/2^-}\rangle $\end{document}

as the

\begin{document}$ \Omega(2012) $\end{document}

resonance, the predicted ratio

\begin{document}$R_{\Xi\bar{K}}^{\Xi\pi\bar{K}}=\mathcal{B}[\Omega^*|1P_{3/2^-}\rangle\to \Xi^*(1530)\bar{K}\to \Xi\pi\bar{K}]/ $\end{document}

\begin{document}$ \mathcal{B}[\Omega^*|1P_{3/2^-}\rangle \to \Xi\bar{K}]\simeq 12{\text%}$\end{document}

is close to the upper limit

\begin{document}$ 11{\text%} $\end{document}

measured by the Belle Collaboration in 2019; however, it is too small to be comparable to the recent measurement

\begin{document}$ 0.97 \pm 0.24\pm 0.07 $\end{document}

. In addition, the coupled-channel effects on the bare three-quark state

\begin{document}$ \Omega^*|1P_{3/2^-}\rangle $\end{document}

from nearby channels

\begin{document}$ \Xi \bar{K} $\end{document}

,

\begin{document}$ \Omega\eta $\end{document}

, and

\begin{document}$ \Xi^*(1530)\bar{K} $\end{document}

are studied. Our theoretical results show that the coupled-channel effects on

\begin{document}$ \Omega^*|1P_{3/2^-}\rangle $\end{document}

are not very large, and the molecular component is no more than

\begin{document}$ 30\% $\end{document}

. To clarify the nature of

\begin{document}$ \Omega(2012) $\end{document}

resonance, precise measurements on the ratio

\begin{document}$ R_{\Xi\bar{K}}^{\Xi\pi\bar{K}} $\end{document}

are needed, and further investigation on the effects of coupled channels is recommended.

Doubly charmed dibaryon states

Zhe Liu, Hong-Tao An, Zhan-Wei Liu, Xiang Liu

2023, 47(6): 063105. doi: 10.1088/1674-1137/acc792

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In this work, we study the doubly charmed dibaryon states with the

\begin{document}$ qqqqcc $\end{document}

(

\begin{document}$ q =u, d, s $\end{document}

) configuration. The mass spectra of doubly charmed dibaryon states are obtained systematically within the chromomagnetic interaction model. In addition to the mass spectrum analysis, we illustrate their two-body strong decay behaviours. Our results suggest that there may be narrow states or even stable states that cannot decay through the strong interaction. We hope that our results will provide valuable information for further experimental searches for doubly charmed dibaryon states.

Hadron spectra and pion form factor in dynamical holographic QCD model with anomalous 5D mass of scalar field

Ruixiang Chen, Danning Li, Kazem Bitaghsir Fadafan, Mei Huang

2023, 47(6): 063106. doi: 10.1088/1674-1137/acc92d

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The simplest version of the dynamical holographic QCD model is described by adding the KKSS model action on a dilaton-graviton coupled background, in which the AdS

\begin{document}$ _5 $\end{document}

metric is deformed by the gluon condensation and further deformed by the chiral condensation. In this framework, both the chiral symmetry breaking and linear confinement can be realized. The light-flavor hadron spectra and the pion form factor were investigated, but it was difficult to reconcile the light-flavor hadron spectra and pion form factor. By considering the anomalous 5-dimension mass correction of the scalar field from QCD running coupling, it is found that the light flavor hadron spectra and pion form factor can be described well simultaneously. In particular, the ground state and lower excitation states of the scalar, pseudo scalar, and axial vector meson spectra are improved. However, the vector meson spectra are not sensitive to the anomalous 5-dimension mass correction of the scalar field.

Investigation of the tetraquark states ${\boldsymbol Qq\bar{\boldsymbol Q} \bar{\boldsymbol q}} $ in the improved chromomagnetic interaction model

Tao Guo, Jianing Li, Jiaxing Zhao, Lianyi He

2023, 47(6): 063107. doi: 10.1088/1674-1137/accb87

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In the framework of the improved chromomagnetic interaction model, we complete a systematic study of the S-wave tetraquark states

\begin{document}$ Qq\bar{Q}\bar{q} $\end{document}

(

\begin{document}$ Q=c,b $\end{document}

, and

\begin{document}$ q=u,d,s $\end{document}

) with different quantum numbers:

\begin{document}$ J^{PC}=0^{+(+)} $\end{document}

,

\begin{document}$ 1^{+(\pm)} $\end{document}

, and

\begin{document}$ 2^{+(+)} $\end{document}

. The mass spectra of tetraquark states are predicted, and the possible decay channels are analyzed by considering both the angular momentum and

\begin{document}$ \mathcal{C} $\end{document}

-parity conservation. The recently observed hidden-charm tetraquark states with strangeness, such as

\begin{document}$ Z_{cs}(3985)^- $\end{document}

,

\begin{document}$ X(3960) $\end{document}

, and

\begin{document}$ Z_{cs}(4220)^+ $\end{document}

, can be well explained in our model. Additionally, according to the wave function of each tetraquark state, we find that the low-lying states of each

\begin{document}$ Qq\bar{Q}\bar{q} $\end{document}

configuration have a large overlap to the

\begin{document}$ Q\bar Q $\end{document}

and

\begin{document}$ q\bar q $\end{document}

meson basis, instead of the

\begin{document}$ Q\bar q $\end{document}

and

\begin{document}$ q\bar Q $\end{document}

meson basis. This indicates that one can search these tetraquark states in future experiments via the channel of

\begin{document}$ Q\bar Q $\end{document}

and

\begin{document}$ q\bar q $\end{document}

mesons.

Glueballs at physical pion mass

Feiyu Chen, Xiangyu Jiang, Ying Chen, Keh-Fei Liu, Wei Sun, Yi-Bo Yang

2023, 47(6): 063108. doi: 10.1088/1674-1137/accc1c

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Glueballs are investigated through gluonic operators on two

\begin{document}$ N_f=2+1 $\end{document}

RBC/UKQCD gauge ensembles at the physical pion mass. The statistical errors of glueball correlation functions are considerably reduced through the cluster decomposition error reduction (CDER) method. The Bethe-Salpeter wave functions are obtained for the scalar, tensor, and pseudoscalar glueballs by using spatially extended glueball operators defined through the gauge potential

\begin{document}$ A_\mu(x) $\end{document}

in the Coulomb gauge. These wave functions exhibit similar features of non-relativistic two-gluon systems and are used to optimize the signals of the related correlation functions at the early time regions, where the ground state masses are extracted. These masses are close to those from the quenched approximation and indicate the possible existence of glueballs at the physical point. The resonance feature of glueballs and the mixing with conventional mesons and multi-hadron systems should be considered in a more systematic lattice study.

Single inclusive hadron production at the LHC with an improved impact parameter dependent saturation model

Xiaofeng Gong, Yanbing Cai, Daicui Zhou, Wenchang Xiang

2023, 47(6): 064101. doi: 10.1088/1674-1137/acc23b

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To obtain a reasonable description of the hadron production at the LHC energies, the impact parameter dependent saturation model is modified by inclusion of an anomalous dimension γ, which controls the slope of the scattering amplitude in the transition from the dilute region to the saturation region. We calculate the transverse momentum distribution and nuclear modification factor of the

\begin{document}$ \pi^0 $\end{document}

and charged hadrons with the improved model, and the results are consistent with measurements performed at the LHC. Moreover, we use the original impact parameter dependent model to study the aforementioned measurements performed at the LHC by adjusting its parameters. We find that the improved model is more consistent with the experimental data than the original one, as the anomalous dimension plays a significant role in the suppression of the evolution of the scattering amplitude.

Robustness of pair structures for nuclear yrast states

Yi-Fei Pan, Yi-Yuan Cheng, Yi Lu, Hui Jiang, Xian-Rong Zhou, Yu-Min Zhao

2023, 47(6): 064102. doi: 10.1088/1674-1137/acc1cc

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Abstract:
In this study, we investigate the robustness of pair structures for nuclear yrast states, that is, whether the structures of relevant collective pairs as building blocks of different yrast states are the same. We focus on deformed and transitional nuclei and study the yrast states of

\begin{document}$ ^{28} $\end{document}

Si,

\begin{document}$ ^{50} $\end{document}

Cr, and

\begin{document}$ ^{132} $\end{document}

Xe, whose experimental

\begin{document}$ R_{4/2} $\end{document}

values are 2.60, 2.40, and 2.16, respectively, using the nucleon-pair approximation (NPA) and shell-model effective interactions. For each yrast state, we consider optimized pair structures to be those providing the energy minimum for this state. To find the minimum, many full NPA calculations are performed with varying pair structures, and the numerical optimization procedure of the conjugate gradient method is implemented. Our results suggest that optimized pair structures remain the same for all states within a rotational band of a deformed nucleus. Our results also suggest that after backbending, that is, changing of the intrinsic state, the structure of the S pair, which is essential to build the monopole pairing correlation, remains approximately unchanged, whereas the structures of the non-S pairs, which are essential to build the quadrupole correlation, change significantly.

Restriction on the form of the quark anomalous magnetic moment from lattice QCD results

Mamiya Kawaguchi, Mei Huang

2023, 47(6): 064103. doi: 10.1088/1674-1137/acc641

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The quark anomalous magnetic moment (AMM) is dynamically generated through spontaneous chiral symmetry breaking. It has been revealed that, even though its exact form is still unknown, the quark AMM is essential to exploring quark matter properties and QCD phase structure under external magnetic fields. In this study, we take three different forms of the quark AMM and investigate its influence on the chiral phase transition under a magnetic field. In general, a negative (positive) quark AMM acts as a magnetic-catalyzer (magnetic-inhibitor) for chiral symmetry breaking. It is found that a constant quark AMM drives an unexpected 1st order chiral phase transition, a quark AMM proportional to the chiral condensate flips the sign on the chiral condensate, and a quark AMM proportional to the square of the chiral condensate suppresses the magnetic enhancement in the chiral condensate at finite temperatures while retaining the chiral crossover phase transition. We also evaluate the intrinsic temperature dependence of the effective AMM form by fitting the effective model result of the chiral condensate to lattice QCD data, which may have a nontrivial correlation with the chiral phase transition.

Elastic scattering based on energy-dependent relativistic Love-Franey model at energies between 20 and 800 MeV

Si-Na Wei, Zhao-Qing Feng

2023, 47(6): 064104. doi: 10.1088/1674-1137/accb88

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Abstract:
In order to investigate the elastic scattering, we fit scattering observables of the weighted fits (WF16) with the relativistic Love-Franey (RLF) model. The masses, cutoff parameters, and initial coupling strengths of RLF are assumed to be independent of energy. Because the energy boundary between low energy and high energy is around 200 MeV, the masses, cutoff parameters, and initial coupling strengths of RLF are obtained by fitting scattering observables of WF16 at an incident energy of 200 MeV. With the masses, cutoff parameters, and initial coupling strengths as the input, the energy-dependent RLF model is constructed over the laboratory energy range of 20 to 800 MeV within a unified fit. To examine the validity of this fit, we investigate p+

\begin{document}$ ^{208}\rm{Pb} $\end{document}

elastic scattering for various energies. Although the scattering observables of pp and pn of 200 MeV best fit the values of WF16, the RLF model of 200 MeV without the Pauli blocking (PB) corrections fails to describe the experimental differential cross sections, analyzing powers, and spinrotation functions. When the PB corrections are taken into account for various energies, the RLF model can well describe the experimental data of p+

\begin{document}$ ^{208}\rm{Pb} $\end{document}

elastic scattering.

Simple scenario of integrated neutron-proton interaction

Xin Yin, Yumin Zhao

2023, 47(6): 064105. doi: 10.1088/1674-1137/acc5dd

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In this study, we investigate the patterns exhibited by integrated neutron-proton interactions (denoted as

\begin{document}$V_{\rm NP}$\end{document}

) that exhibit systematic differences among particle-particle, hole-hole, hole-particle, and particle-hole cases. A simple formula of

\begin{document}$V_{\rm NP}$\end{document}

is proposed to be in approximate linearity with

\begin{document}$N_{n} N_{p}$\end{document}

. This formula yields regular patterns of