## 2024 Vol. 48, No. 6

Display Method: |

2024, 48(6): 063001. doi: 10.1088/1674-1137/ad3943

**Abstract:**

Particle

*S*-wave Breit-Wigner resonance. We performed a global fit to the distributions of invariant mass of

2024, 48(6): 063101. doi: 10.1088/1674-1137/ad2f22

**Abstract:**

The finite mass of the heavy quark suppresses the collimated radiations; this is generally referred to as the dead cone effect. In this paper, we study the distribution of hadron multiplicity over the hadron opening angle with respect to the jet axis for various jet flavors. The corresponding measurement can be the most straightforward and simplest approach to explore the dynamical evolution of the radiations in the corresponding jet, which can expose the mass effect. We also propose a transverse energy-weighted angular distribution, which sheds light on the interplay between perturbative and non-perturbative effects in the radiation. Through Monte-Carlo simulations, our calculations show that the dead cone effect can be clearly observed by finding the ratio between the

*b*and light-quark (inclusive) jets; this is expected to be measured at the LHC in the future.

2024, 48(6): 063102. doi: 10.1088/1674-1137/ad2f23

**Abstract:**

We constructed a gauge

*CP*phases via the type-I seesaw mechanism. Six quark mases, three quark mixing angles, and the

*CP*phase in the quark sector take the central values whereas Yukawa couplings in the quark sector are diluted in a range of difference of three orders of magnitude by the perturbation theory at the first order. Concerning the neutrino sector, a small neutrino mass is achieved by the type-I seesaw mechanism. Both inverted and normal neutrino mass hierarchies are consistent with the experimental data. The predicted sum of neutrino masses for normal and inverted hierarchies, the effective neutrino masses, and the Dirac

*CP*phase are also consistent with recently reported limits.

2024, 48(6): 063103. doi: 10.1088/1674-1137/ad305f

**Abstract:**

In this study, the spectroscopic parameters of exotic molecular states composed of mesons containing two heavy quarks (scalar - axial and pseudoscalar - axial meson combinations) are investigated within the QCD sum rules. Our findings reveal that molecular states containing charm quarks do not form bound states, whereas states with

*b*-quarks can form exotic molecular states. This observation has significant implications for understanding the structure of these exotic states.

2024, 48(6): 063104. doi: 10.1088/1674-1137/ad305d

**Abstract:**

An approximated solution for the gluon distribution from DGLAP evolution equations with the NLO splitting function in the small-

*x*limit is presented. We first obtain simplified forms of the LO and NLO splitting functions in the small-

*x*limit. With these approximated splitting functions, we obtain the analytical gluon distribution using the Mellin transform. The free parameters in the boundary conditions are obtained by fitting the CJ15 gluon distribution data. We find that the asymptotic behavior of the gluon distribution is consistent with the CJ15 data; however, the NLO results considering the "ladder" structure of gluon emission are slightly better than the LO results. These results indicate that the corrections from NLO have a significant influence on the behavior of the gluon distribution in the small-

*x*region. In addition, we investigate the DGLAP evolution of the proton structure function using the analytical solution of the gluon distribution. The differential structure function reveals that our results have a similar tendency to the CJ15 data at small-

*x*.

2024, 48(6): 063105. doi: 10.1088/1674-1137/ad33be

**Abstract:**

This study aims to investigate Lorentz/

*U*(1) gauge symmetry-breaking electrodynamics in the framework of the standard-model extension and analyze the Hamiltonian structure for the theory with a specific dimension

*U*(1) gauge symmetry-breaking operators are present, the theories generally lack a first-class constraint and have one additional physical degree of freedom compared to the standard Maxwell electrodynamics.

2024, 48(6): 063106. doi: 10.1088/1674-1137/ad2362

**Abstract:**

In this study, we systematically investigate collider constraints on effective interactions between Dark Matter (DM) particles and electroweak gauge bosons. We consider the simplified models in which scalar or Dirac fermion DM candidates couple only to electroweak gauge bosons through high dimensional effective operators. Considering the induced DM-quarks and DM-gluons operators from the Renormalization Group Evolution (RGE) running effect, we present comprehensive constraints on the effective energy scale Λ and Wilson coefficients

*j*and mono-

*γ*search limits at the Large Hadron Collider (LHC), and derive the new limits at the Circular Electron Positron Collider (CEPC).

2024, 48(6): 063107. doi: 10.1088/1674-1137/ad30f0

**Abstract:**

In this paper, we investigate the charmed meson rare decay process

*ξ*-moments. Then, the

2024, 48(6): 063108. doi: 10.1088/1674-1137/ad34be

**Abstract:**

Motivated by our previous study [Phys. Rev. D 104(1), 016021 (2021)] on the pionic leading-twist distribution amplitude (DA), we revisit the

*ρ*-meson leading-twist longitudinal DA

*ξ*-moments of

*ξ*-moments at the typical scale

*i.e.*,

2024, 48(6): 063109. doi: 10.1088/1674-1137/ad34c4

**Abstract:**

We studied the spectrum and rearrangement decays of

*S*-wave

2024, 48(6): 064001. doi: 10.1088/1674-1137/ad2dc3

**Abstract:**

TALYS calculations were performed to obtain the theoretical proton capture cross-sections on the

*p*-nuclei. A short review on the status of related experimental studies was also conducted. Some basic properties such as

*Q*-values, Coulomb barrier, Gamow peak, Gamow Window, and decay properties of the parent and daughter nuclei were studied. Various experimental parameters, e.g., beam energy, beam current, targets, and detectors, used in experimental investigations reported in the literature, were tabulated. The results of the TALYS calculations in the Gamow region were compared with the corresponding experimental values wherever available. This study is expected to facilitate the planning of future experiments.

2024, 48(6): 064002. doi: 10.1088/1674-1137/ad361a

**Abstract:**

The complete-fusion reaction

^{204}Pb(

^{48}Ca,2

*n*)

^{250}No was used to study two activities of

^{250}No with distinct half-lives. A total of 1357 events were observed in the SFiNx neutron detection system. The average number of neutrons emitted per spontaneous fission of

^{250}No was determined to be

2024, 48(6): 064101. doi: 10.1088/1674-1137/ad30ef

**Abstract:**

Cluster radioactivity is studied within the generalized liquid drop model (GLDM), in which the shell correction energy, pairing energy, and cluster preformation factor are considered. The calculations show significant improvements and can reproduce the experimental data within a factor of 8.04 after considering these physical effects. In addition, the systematic trend of the cluster preformation factors

*et al.*,

*et al.*, this study suggests that the linear relationship between

2024, 48(6): 064102. doi: 10.1088/1674-1137/ad305c

**Abstract:**

In this study, we systematically analyzed the ground state of uranium isotopes from 225 to 240. In our calculations, we used the covariant energy density functional of density-dependent meson exchange interaction (DD-ME2) with separable pairing interaction (TMR). Using the multiple deformation constraint, we calculated the potential energy surface (PES) of the uranium isotopes for both even-even and even-odd nuclei with quadrupole and octupole deformation. Based on our calculation and upon comparing the experimental data and Hartree-Fock-Bogoliubov calculations with Gogny D1S calculation data, the ground state of uranium isotopes with reflection-asymmetric deformation was found to be preferred.

2024, 48(6): 064103. doi: 10.1088/1674-1137/ad33bd

**Abstract:**

Traditionally, isoscaling has been interpreted and applied within the framework of the grand canonical ensemble, based on the assumption that fragment production occurs following the attainment of a statistical equilibrium state. However, the influence of the symmetry energy can lead to differences in the neutron and density distribution in neutron-rich nuclei. This in turn may impact the isoscaling parameters (usually denoted by

*α*and

*β*). We examine the isoscaling properties for neutron-rich fragments produced in highly asymmetric systems on inverse kinematics, namely

*α*and

*β*values and sort them as a function of the neutron excess

*α*extracted from fragments within different ranges of

*I*emphasize the importance of understanding the dependence of isoscaling parameters on fragments generated in various collision regions. Furthermore, the

2024, 48(6): 064104. doi: 10.1088/1674-1137/ad2dc1

**Abstract:**

Numerous experimental and theoretical observations have concluded that the probability of the three fragment emission (ternary fission) or binary fission increases when one proceeds towards the heavy mass region of nuclear periodic table. Many factors affect fragment emission, such as the shell effect, deformation, orientation, and fissility parameter. Binary and ternary fissions are observed for both ground and excited states of the nuclei. The collinear cluster tripartition (CCT) channel of the

*n*

*f*) reaction is studied, and we observe that the CCT may be a sequential or simultaneous emission phenomenon. To date, different approaches have been introduced to study the CCT process as a simultaneous or sequential process, but the decay dynamics of these modes have not been not fully explored. Identifying the three fragments of the sequential process and exploring their related dynamics using an excitation energy dependent approach would be of further interest. Hence, in this study, we investigate the sequential decay mechanism of the

*n*

*f*) reaction using quantum mechanical fragmentation theory (QMFT). The decay mechanism is considered in two steps, where initially, the nucleus splits into an asymmetric channel. In the second step, the heavy fragment obtained in the first step divides into two fragments. Stage I analysis is conducted by calculating the fragmentation potential and preformation probability for the spherical and deformed choices of the decaying fragments. The most probable fragment combination of stage I are identified with respect to the dips in the fragmentation structure and the corresponding maxima of the preformation probability (

2024, 48(6): 064105. doi: 10.1088/1674-1137/ad3814

**Abstract:**

The recent measurements of neutron skins via parity violation in electron scattering have extracted an abnormally thick neutron skin for

2024, 48(6): 064106. doi: 10.1088/1674-1137/ad361d

**Abstract:**

Accurately determining the quadrupole deformation parameters of atomic nuclei is crucial for understanding their structural and dynamic properties. This study introduces an innovative approach that combines transfer learning techniques with neural networks to predict the quadrupole deformation parameters of even-even nuclei. With the application of this innovative technique, the quadrupole deformation parameters of 2331 even-even nuclei are successfully predicted within the nuclear region defined by proton numbers

2024, 48(6): 065001. doi: 10.1088/1674-1137/ad2e82

**Abstract:**

The full array of the Large High Altitude Air Shower Observatory (LHAASO) has been in operation since July 2021. For its kilometer-square array (KM2A), we optimized the selection criteria for very high and ultra-high energy

*γ*-rays using data collected from August 2021 to August 2022, resulting in an improvement in significance of the detection in the Crab Nebula of approximately 15%, compared with that of previous cuts. With the implementation of these new selection criteria, the angular resolution was also significantly improved by approximately 10% at tens of TeV. Other aspects of the full KM2A array performance, such as the pointing error, were also calibrated using the Crab Nebula. The resulting energy spectrum of the Crab Nebula in the energy range of 10-1000 TeV are well fitted by a log-parabola model, which is consistent with the previous results from LHAASO and other experiments.

2024, 48(6): 065101. doi: 10.1088/1674-1137/ad32c0

**Abstract:**

By considering the concept of a unified single fluid model, referred to as modified Chaplygin gas (MCG), which amalgamates dark energy and dark matter, we explore the thermodynamic characteristics of charged anti-de Sitter (AdS) black holes existing in an unconventional fluid accompanied by MCG. To accomplish this objective, we derive the equations of state by regarding the charge

*γ*and

*β*have a non-negligible effect on the isenthalpic curve.

2024, 48(6): 065102. doi: 10.1088/1674-1137/ad34c0

**Abstract:**

Recently, the emergence of cosmological tension has raised doubts about the consistency of the ΛCDM model. To constrain the neutrino mass within a consistent cosmological framework, we investigate three massive neutrinos with normal hierarchy (NH) and inverted hierarchy (IH) in both the axion-like early dark energy (Axi-EDE) and AdS-EDE models. We use joint datasets including the cosmic microwave background power spectrum from

*Planck*2018, Pantheon of type Ia supernova, baryon acoustic oscillation, and

*ν*Axi-EDE model, we obtain

*ν*AdS-EDE model, we find

*ν*Axi-EDE and

*ν*AdS-EDE models.

2024, 48(6): 065103. doi: 10.1088/1674-1137/ad34c2

**Abstract:**

In the frequency band of the Laser Interferometer Space Antenna (LISA), extensive research has been conducted on the impact of foreground confusion noise generated by galactic binaries within the Milky Way Galaxy. Additionally, recent evidence of a stochastic signal, announced by the NANOGrav, EPTA, PPTA, CPTA, and InPTA, indicates that the stochastic gravitational-wave background (SGWB) generated by supermassive black hole binaries (SMBHBs) can contribute strong background noise within the LISA band. Given the presence of such strong noise, it is expected to have significant impacts on LISA's scientific missions. In this study, we investigate the impacts of the SGWB generated by SMBHBs on the detection of individual massive black hole binaries, verified galactic binaries, and extreme mass ratio inspirals in the context of LISA. We find it essential to resolve and eliminate the excess noise from the SGWB to guarantee the success of LISA's missions.

2024, 48(6): 065104. doi: 10.1088/1674-1137/ad361c

**Abstract:**

We study the dynamics of the critical collapse of a spherically symmetric scalar field. Approximate analytic expressions for the metric functions and matter field in the large-radius region are obtained. In the central region, owing to the boundary conditions, the equation of motion for the scalar field is reduced to the flat-spacetime form.

2024, 48(6): 065105. doi: 10.1088/1674-1137/ad34bf

**Abstract:**

In this work, the optical appearance of an asymmetric thin-shell wormhole with a Bardeen profile is studied. To initiate the process, we need to construct an asymmetric thin-shell wormhole utilizing the cut-and-paste technique proposed by Visser and subsequently ascertain its pertinent physical quantities such as the radius of the photon sphere and critical impact parameters for different values of magnetic charge

*g*. Then, the effective potential and motion behavior of photons are also investigated within the framework of asymmetric thin-shell wormholes with a Bardeen profile. It can be found that the effective potential, ray trajectory, and azimuthal angle of the thin-shell wormhole exhibit a strong correlation with the mass ratio of black holes. By considering the accretion disk as the sole background light source, we observe additional photon rings and lensing bands in the optical appearance of the asymmetric thin-shell wormhole with a Bardeen profile compared to those exhibited by the Bardeen black hole. One can find that there is an increase in the size of the specific additional light bands with increasing magnetic charge

*g*, which is different from the black hole case. These exceptionally luminous rings can serve as a robust criterion for the identification and characterization of the thin-shell wormhole spacetime.

2024, 48(6): 065106. doi: 10.1088/1674-1137/ad32be

**Abstract:**

In this study, we extend the surface growth approach for bulk reconstruction into the AdS spacetime with a boundary in the AdS/BCFT correspondence. We show that the geometry in the entanglement wedge with a boundary can be constructed from the direct growth of bulk extremal surfaces layer by layer. Furthermore, we observe that the surface growth configuration in BCFT can be connected with the defect multi scale entanglement renormalization ansatz (MERA) tensor network. Additionally, we investigate the entanglement of purification within the surface growth process, which not only reveals more refined structure of entanglement entropy in the entanglement wedge but also suggests a selection rule for surface growth in the bulk reconstruction.

2024, 48(6): 065107. doi: 10.1088/1674-1137/ad361e

**Abstract:**

High-energy photons may oscillate with axion-like particles (ALPs) when they propagate through the Milky Way's magnetic field, resulting in an alteration in the observed photon energy spectrum. Ultra-high energy gamma-ray spectra, measured by the Large High Altitude Air Shower Observatory (LHAASO) up to

_{s}method to set constraints on the ALP parameters. Our analysis of the observations of the four sources reveals that the ALP-photon coupling

2024, 48(6): 065108. doi: 10.1088/1674-1137/ad34bd

**Abstract:**

In this paper, we undertake a detailed study of real scalar inflation using LATTICEEASY simulations to investigate preheating phenomena. Generally, the scalar inflation potential with non-minimal coupling can be approximated using a quartic potential. We observe that the evolutionary behavior of this potential remains unaffected by the coupling coefficient. Furthermore, the theoretical predictions for the scalar spectral index (

*r*) are independent of this coefficient. Consequently, the coefficients of this model are not constrained by Planck observations. Fortunately, the properties of preheating after inflation provide a viable approach to examining these coefficients. Through LATTICEEASY simulations, we trace the evolution of particle number density, scale factor, and energy density during the preheating process. Subsequently, we derive the parameters, such as the energy ratio (

*γ*) and the

*e*-folding number of preheating (

*r*. We successfully validate real scalar inflation model using preheating in LATTICEEASY simulations based on the analytical relationship between preheating and inflation models.

2024, 48(6): 065109. doi: 10.1088/1674-1137/ad361f

**Abstract:**

We obtain an exact solution for spherically symmetric Letelier AdS black holes immersed in perfect fluid dark matter (PFDM). Considering the cosmological constant as the positive pressure of the system and volume as its conjugate variable, we analyze the thermodynamics of our black holes in the extended phase space. Owing to the background clouds of strings parameter (

*a*) and the parameter endowed with PFDM (

*β*), we analyze the Hawking temperature, entropy, and specific heat. Furthermore, we investigate the relationship between the photon sphere radius and phase transition for the Letelier AdS black holes immersed in PFDM. Through the analysis, with a particular condition, non-monotonic behaviors are found between the photon sphere radius, impact parameter, PFDM parameter, temperature, and pressure. We can regard the changes in both the photon sphere radius and impact parameter before and after phase transition as the order parameter; their critical exponents near the critical point are equal to the same value, 1/2, similar to that in ordinary thermal systems. This indicates that a universal relation of gravity may exist near the critical point for a black hole thermodynamic system.

**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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