## 2024 Vol. 48, No. 10

Display Method: |

2024, 48(10): 101001. doi: 10.1088/1674-1137/ad75f4

**Abstract:**

There is a long-standing puzzle that the CP violation (CPV) in the baryon systems has never been well established in experiments, while the CPV of mesons have been observed by decades. In this paper, we propose that the CPV of baryon decays can be generated with the rescatterings of a nucleon and a pion into some final states, i.e.

2024, 48(10): 103001. doi: 10.1088/1674-1137/ad597b

**Abstract:**

We operated a

*p*-type point contact high purity germanium (PPCGe) detector (CDEX-1B, 1.008 kg) in the China Jinping Underground Laboratory (CJPL) for 500.3 days to search for neutrinoless double beta (

^{76}Ge. A total of 504.3 kg

^{76}Ge

2024, 48(10): 103101. doi: 10.1088/1674-1137/ad5f80

**Abstract:**

In this paper, we introduce a novel approach in quantum field theories to estimate actions using artificial neural networks (ANNs). The actions are estimated by learning system configurations governed by the Boltzmann factor,

2024, 48(10): 103102. doi: 10.1088/1674-1137/ad5661

**Abstract:**

Multi-boson productions can be exploited as novel probes either for standard model precision tests or new physics searches, and have become a popular research topic in ongoing LHC experiments and future collider studies, including those for electron–positron and muon–muon colliders. In this study, we focus on two examples,

*i.e*.,

2024, 48(10): 103103. doi: 10.1088/1674-1137/ad5ae5

**Abstract:**

In this study, we chose the diquark-antidiquark type four-quark currents with an explicit

*P*-wave between the diquark and antidiquark pairs to study the ground states and first radial excitations of the hidden-charm tetraquark states with quantum numbers

2024, 48(10): 103104. doi: 10.1088/1674-1137/ad5a71

**Abstract:**

In this study, we use the optical theorem to calculate the next-to-leading order corrections to the QCD spectral densities directly in the QCD sum rules for the pseudoscalar and scalar

*B*

_{c}mesons. We use experimental data for guidance to perform an updated analysis. We obtain the masses and, in particular, decay constants, which are the fundamental input parameters in high energy physics. Ultimately, we obtain the pure leptonic decay widths, which can be compared with experimental data in the future.

2024, 48(10): 103105. doi: 10.1088/1674-1137/ad62d8

**Abstract:**

The decay of Higgs boson into two spin-1/2 particles provides an ideal system to reveal quantum entanglement and Bell-nonlocality. Future

*i.e*., Törnqvist's method and Clauser-Home-Shimony-Holt (CHSH) inequality. In the simulation, we consider the detector effects of CEPC including uncertainties for tracks and jets from

*Z*boson in the production of

2024, 48(10): 103106. doi: 10.1088/1674-1137/ad6416

**Abstract:**

We investigate the inelastic signatures of dark matter-nucleus interactions, explicitly focusing on the ramifications of polarization, dark matter splitting, and the Migdal effect. Direct detection experiments, crucial for testing the existence of dark matter, encounter formidable obstacles, such as indomitable neutrino backgrounds and elusive determination of dark matter spin. To overcome these challenges, we explore the potential of polarized-target dark matter scattering, examining the impact of nonvanishing mass splitting, and the role of the Migdal effect in detecting dark matter. Our analysis demonstrates the valuable utility of the polarized triple-differential event rate as an effective tool for examining inelastic dark matter. It enables us to investigate angular and energy dependencies, providing valuable insights into the scattering process.

2024, 48(10): 103107. doi: 10.1088/1674-1137/ad5e65

**Abstract:**

We present the angular distribution of the four-fold

2024, 48(10): 103108. doi: 10.1088/1674-1137/ad6552

**Abstract:**

In this study, the properties of heavy quarkonia

*X*are examined by treating them as bound states of

*Q*and

*Q*represents either a charm or bottom quark. The branching ratios for the radiative leptonic decays

*X*. Furthermore, we apply Lorentz transformations from the rest frame of

*X*to the center-of-mass frame of

*X*states, such as

2024, 48(10): 103109. doi: 10.1088/1674-1137/ad62d9

**Abstract:**

In this study, we investigated the anomalous Chromomagnetic Dipole Moment (CMDM), denoted as

*B*, and heavy bosons

2024, 48(10): 103110. doi: 10.1088/1674-1137/ad595a

**Abstract:**

In this study, we analyzed masses and decays of triply-heavy pentaquarks

2024, 48(10): 103111. doi: 10.1088/1674-1137/ad6752

**Abstract:**

We propose searching for dark photon signals in the decay channel of

*η*mesons, specifically through the leptonic decay (

2024, 48(10): 104001. doi: 10.1088/1674-1137/ad5ae6

**Abstract:**

Accurate cross sections of neutron induced fission reactions are required in the design of advanced nuclear systems and the development of fission theory. Time projection chambers (TPCs), with their track reconstruction and particle identification capabilities, are considered the best detectors for high-precision fission cross section measurements. The TPC developed by the back-streaming white neutron source (Back-n) team of the China Spallation Neutron Source (CSNS) was used as the fission fragment detector in measurements. In this study, the cross sections of the

^{232}Th(

*n*,

*f*) reaction at five neutron energies in the 4.50−5.40 MeV region were measured. The fission fragments and α particles were well identified using our TPC, which led to a higher detection efficiency of the fission fragments and smaller uncertainty of the measured cross sections. Ours is the first measurement of the

^{232}Th(

*n, f*) reaction using a TPC for the detection of fission fragments. With uncertainties less than 5%, our cross sections are consistent with the data in different evaluation libraries, including JENDL-4.0, ROSFOND-2010, CENDL-3.2, ENDF/B-VIII.0, and BROND-3.1, whose uncertainties can be reduced after future improvement of the measurement.

2024, 48(10): 104002. doi: 10.1088/1674-1137/ad66c0

**Abstract:**

The neutron total cross-section of

2024, 48(10): 104101. doi: 10.1088/1674-1137/ad57a6

**Abstract:**

A variable moment of inertia (VMI) inspired interacting boson model (IBM), which includes many-body interactions and a perturbation possessing

*γ*-transition energy as well as the kinematic and dynamic moments of inertia (MoIs) within the rotational bands of

2024, 48(10): 104102. doi: 10.1088/1674-1137/ad5ae8

**Abstract:**

By varying the intrinsic initial geometry,

*p*/

*d*/

^{3}He+Au collisions at the Relativistic Heavy Ion Collider (RHIC) provide a unique opportunity to understand the collective behavior and probe possible sub-nucleon fluctuations in small systems. In this study, we employed the hybrid model

*p*/

*d*/

^{3}He+Au collisions. With fine-tuned parameters,

2024, 48(10): 104103. doi: 10.1088/1674-1137/ad5e66

**Abstract:**

A method based on the dinuclear system (DNS) is proposed to describe the angular distribution of products in multinucleon transfer (MNT) reactions. By considering fluctuation effects, the angular distributions of reactions involving

^{136}Xe+

^{208}Pb,

^{136}Xe+

^{209}Bi,

^{86}Kr+

^{166}Er,

^{ 84}Kr+

^{209}Bi, and

^{84}Kr+

^{208}Pb are examined, demonstrating good agreement with experimental data. Moreover, the double differential cross-sections (

^{136}Xe+

^{208}Pb and

^{136}Xe+

^{209}Bi are analyzed to explore the mechanism of angular distribution in MNT reactions. Additionally, the optimal angles for detecting

*N*=126 isotopes are determined via an analysis on the influence of proton and neutron numbers of the projectiles on the angular distribution of the

*N*=126 isotopic line. The results of this study can provide valuable insights for experimental detection.

2024, 48(10): 104104. doi: 10.1088/1674-1137/ad5d63

**Abstract:**

The aim of this study is to construct inverse potentials for various

*ℓ*-channels of neutron-proton scattering using a piece-wise smooth Morse function as a reference. The phase equations for single-channel states and the coupled equations of multi-channel scattering are solved numerically using the 5

^{th}order Runge-kutta method. We employ a piece-wise smooth reference potential comprising three Morse functions as the initial input. Leveraging a machine learning-based genetic algorithm, we optimize the model parameters to minimize the mean-squared error between simulated and anticipated phase shifts. Our approach yields inverse potentials for both single and multi-channel scattering, achieving convergence to a mean-squared error

*r"*for

*r*], are found to be [5.445(5.424), 1.770(1.760)]

2024, 48(10): 104105. doi: 10.1088/1674-1137/ad62dd

**Abstract:**

The inner fission barriers of the even-even uranium isotopes from the proton to the neutron drip line are examined using the deformed relativistic Hartree-Bogoliubov theory in continuum. A periodic-like evolution for the ground state shapes is shown with respect to the neutron number,

*i.e.*, spherical shapes at shell closures

*r*-process nucleosynthesis.

2024, 48(10): 104106. doi: 10.1088/1674-1137/ad62d7

**Abstract:**

It is generally agreed upon that the pressure inside a neutron star is isotropic. However, a strong magnetic field or superfluidity suggests that the pressure anisotropy may be a more realistic model. We derived the dimensionless TOV equation for anisotropic neutron stars based on two popular models, namely, the BL and H models, to investigate the effect of anisotropy. Similar to the isotropic case, the maximum mass

^{3}to 510 − 1005 MeV/fm

^{3}, and the extracted radial central pressure

^{3}to 76 − 271 MeV/fm

^{3}. For

^{3}and 50 − 165 MeV/fm

^{3}, respectively. In the H model, for

^{3}, and the extracted

^{3}. For

^{3}, and the extracted

^{3}.

2024, 48(10): 104107. doi: 10.1088/1674-1137/ad62da

**Abstract:**

The transverse momentum distributions of charged hadrons produced in proton-proton collisions at center-of-mass energies (

*T*), non-extensivity parameter (

*q*), and kinetic freezeout volume (

*V*). Additionally, the mean transverse momentum (

*T*) of the particle source are determined through the fit function and string percolation method, respectively. An alternative method is employed to calculate the kinetic freezeout temperature (

_{i}*T*. Furthermore, thermodynamic quantities at the freezeout, including energy density (

*ε*), particle density (

*n*), entropy density (

*s*), pressure (

*P*), and squared speed of sound (

*T*and

*q*. It is also observed that, with a decrease in pseudorapidity, all thermodynamic quantities except

*V*and

*q*increase. This trend is attributed to greater energy transfer along the mid pseudorapidity.

*q*increases towards higher values of pseudorapidity, indicating that particles close to the beam axis are far from equilibrium. Meanwhile,

*V*remains nearly independent of pseudorapidity. The excitation function of these parameters (

*q*) shows a direct (inverse) correlation with collision energy. The

*ε*,

*n*,

*s*, and

*P*show a strong dependence on collision energies at low pseudorapidities. Explicit verification of the thermodynamic inequality

2024, 48(10): 104108. doi: 10.1088/1674-1137/ad6417

**Abstract:**

In this work, considering the preformation factor of the emitted two protons in parent nucleus

**47**, 025102 (2020)] to systematically study

*σ*= 0.683. For comparison, we include the Gamow-like model (GLM) proposed by Liu

*et al*. [Chin. Phys. C

**45**, 044110 (2021)], generalized liquid drop model (GLDM) proposed by Cui

*et al*. [Phys. Rev. C

**101**, 014301 (2020)], effective liquid drop model (ELDM) proposed by M. Gonalves

*et al*. [Phys. Lett. B

**774**, 14 (2017)], two-potential approach with Skyrme-Hartree-Fock (TPASHF) proposed by Pan

*et al*. [Chin. Phys. C

**45**, 124104 (2021)], phenomenological model with a screened electrostatic barrier (SEB) propoesed by Zou

*et al*. [Chin. Phys. C

**45**, 104101 (2021)], unified fission model (UFM) proposed by Xing

*et al*. [Chin. Phys. C

**45**, 124105 (2021)], Coulomb and proximity potential model for deformed nuclei (CPPMDN) proposed by Santhosh [Phys. Rev. C

**104**, 064613 (2021)], two-parameter empirical formula proposed by Liu

*et al*. [Chin. Phys. C

**45**, 024108 (2021)], and four-parameter empirical formula proposed by Sreeja

*et al*. [Eur. Phys. J. A

**55**, 33 (2019)]. In addition, we use this model to predict the

2024, 48(10): 105001. doi: 10.1088/1674-1137/ad5bd4

**Abstract:**

Using the GEANT4 and Cosmic Ray Monte Carlo (CRMC) software packages, we developed a new simulation toolkit for astrophysical neutrino telescopes. By configuring the Baikal-GVD detector and comparing the vertex position and direction of incident particles, as well as the channel-by-channel signals, to the events detected by Baikal-GVD, we successfully generated 13 high-energy cascade neutrino events with the toolkit. Our analysis revealed a systematic offset between the reconstructed shower position and the true interaction position, with a distance close to the scale of the shower maximum of −0.54±1.29 m. We achieved a good linear relationship between the photoelectron number of neutrino events obtained by simulation and the real data measured by Baikal-GVD. The simulation toolkit could serve as a reliable basis for studying the performance of astrophysical neutrino telescopes.

2024, 48(10): 105101. doi: 10.1088/1674-1137/ad5f81

**Abstract:**

Traditionally, the cosmological constant has been viewed as dark energy that mimics matter with negative energy. Given that matter with negative energy provides a repulsive force, which fundamentally differs from typical gravitational forces, it has been believed that the cosmological constant effectively contributes a repulsive force. However, it is important to note that the concept of gravitational force is valid only within the framework of Newtonian dynamics. In this study, we demonstrate that the traditional understanding of the gravitational force contributed by the cosmological constant is not entirely correct. Our approach involves investigating the Newtonian limit of the Einstein equation with a cosmological constant. The subtleties involved in this analysis are discussed in detail. Interestingly, we find that the effect of the cosmological constant on Newtonian gravity is an attractive force rather than a repulsive one for ordinary matter. As expected, this corrective force is negligibly small. However, our findings may offer a way to distinguish between dark energy and the cosmological constant, as one contributes a repulsive force while the other contributes an attractive force.

2024, 48(10): 105102. doi: 10.1088/1674-1137/ad62db

**Abstract:**

The spin characteristics of black holes offer valuable insights into the evolutionary pathways of their progenitor stars. This is crucial for understanding the broader population properties of black holes. Traditional hierarchical Bayesian inference techniques employed to discern these properties often demand substantial time, and consensus regarding the spin distribution of binary black hole (BBH) systems remains elusive. In this study, leveraging observations from GWTC-3, we adopted a machine learning approach to infer the spin distribution of black holes within BBH systems. Specifically, we developed a deep neural network (DNN) and trained it using data generated from a Beta distribution. Our training strategy, involving the segregation of data into 10 bins, not only expedites model training but also enhances the versatility and adaptability of the DNN to accommodate the growing volume of gravitational wave observations. Utilizing Monte Carlo-bootstrap (MC-bootstrap) to generate observation-simulated samples, we derived spin distribution parameters:

2024, 48(10): 105103. doi: 10.1088/1674-1137/ad5660

**Abstract:**

We investigate the shadows of the Konoplya-Zhidenko naked singularity. In the spacetime of the Konoplya-Zhidenko naked singularity, not only an unstable retrograde light ring (LR) but also an unstable prograde LR exists, leading to the formation of a complete photon sphere (PS). Due to the absence of an event horizon, a dark disc-shaped shadow does not appear; instead, a ring-shaped shadow is observed. The ring-shaped shadow appears as an infinite number of relativistic Einstein rings in the image of the naked singularity. For some parameter values, only the unstable retrograde LR exists, resulting in an incomplete unstable PS and thus giving rise to an arc-shaped shadow for the Konoplya-Zhidenko naked singularity. The shadow of the Konoplya-Zhidenko naked singularity gradually shifts to the right as the rotation parameter

*a*increases and gradually becomes smaller as the deformation parameter

**ISSN** 1674-1137 **CN** 11-5641/O4

Original research articles, Ietters and reviews Covering theory and experiments in the fieids of

- Particle physics
- Nuclear physics
- Particle and nuclear astrophysics
- Cosmology

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