## 2021 Vol. 45, No. 5

Display Method: |

2021, 45(5): 053001. doi: 10.1088/1674-1137/abe36d

**Abstract:**

We investigate the parton distribution function (PDF) uncertainty in the measurement of the effective weak mixing angle

*Z-*pole region, while most of the sensitivity in reducing the PDF uncertainty remains. Furthermore, the lepton charge asymmetry in the

*W*boson events as a function of the rapidity of the charged leptons,

2021, 45(5): 053002. doi: 10.1088/1674-1137/abe8cf

**Abstract:**

Measuring the pionic structure function is of high interest, as it provides a new area for understanding the strong interaction among quarks and testing QCD predictions. To this end, we investigate the feasibility and expected impact of a possible experiment at EicC (Electron-ion collider in China). We show the simulation results on the statistical precision of an EicC measurement, based on the model of leading neutron tagged DIS process and the parton distribution functions of the pion from JAM18 global analysis. The simulation shows that at EicC, the kinematics cover the

2021, 45(5): 053003. doi: 10.1088/1674-1137/abeb07

**Abstract:**

We report a feasibility study for violation in

2021, 45(5): 053101. doi: 10.1088/1674-1137/abe36b

**Abstract:**

Applying the effective Lagrangian method, we study the flavor changing neutral current process

2021, 45(5): 053102. doi: 10.1088/1674-1137/abe84d

**Abstract:**

The

2021, 45(5): 053103. doi: 10.1088/1674-1137/abe8ce

**Abstract:**

We present an analysis of the newly observed pentaquark

2021, 45(5): 053104. doi: 10.1088/1674-1137/abeb06

**Abstract:**

Within the quasi-two-body decay model, we study the localized CP violation and branching fraction of the four-body decay

2021, 45(5): 053105. doi: 10.1088/1674-1137/abec68

**Abstract:**

The doubly charmed baryon

2021, 45(5): 054001. doi: 10.1088/1674-1137/abe36c

**Abstract:**

Fusion-evaporation cross sections of

*n*)

*n*)

2021, 45(5): 054002. doi: 10.1088/1674-1137/abe763

**Abstract:**

Spin alignments of vector mesons and hyperons in relativistic heavy-ion collisions have been proposed as signals of global polarization. The STAR experiment first observed the

2021, 45(5): 054101. doi: 10.1088/1674-1137/abe368

**Abstract:**

In this work, we study the renormalization group invariance of the recently proposed covariant power counting in the case of nucleon-nucleon scattering [Chin. Phys. C 42 (2018) 014103] at leading order. We show that unlike the Weinberg scheme, renormalizaion group invariance is satisfied in the

2021, 45(5): 054102. doi: 10.1088/1674-1137/abe3ec

**Abstract:**

The photoproduction of the bottomonium-like states

*t*-channel with

2021, 45(5): 054103. doi: 10.1088/1674-1137/abe3ed

**Abstract:**

In this paper, we propose an approach to nucleon-pair approximation (NPA) with

*m*-scheme bases, in which the collective nucleon pairs are represented in terms of antisymmetric matrices, and commutations between nucleon pairs are given using a matrix multiplication that avoids angular-momentum couplings and recouplings. Therefore the present approach significantly simplifies the NPA computation. Furthermore, it is formulated on the same footing with and without isospin.

2021, 45(5): 054104. doi: 10.1088/1674-1137/abe3ee

**Abstract:**

Coincidence measurements of breakup fragments in reactions of

*Q*values along with the relative energies of the breakup fragments, different breakup components (prompt breakups and delayed breakups) and different breakup modes (

2021, 45(5): 054105. doi: 10.1088/1674-1137/abe84f

**Abstract:**

Experimental elastic scattering angular distributions of

^{11}B,

^{12}C, and

^{16}O + heavy-ions are used to study the Woods-Saxon potential parameters. Best fitted values of the diffuseness parameters are found for each system, and a linear relationship is expressed between the diffuseness parameters and

^{11}B,

^{12}C, and

^{16}O but also some elastic scattering induced by other heavy-ions.

2021, 45(5): 054106. doi: 10.1088/1674-1137/abe9a2

**Abstract:**

Several different transport processes, such as heat, momentum, and charge transports, may occur simultaneously in a thermal plasma system. The corresponding transport coefficients are heat conductivity, shear viscosity, and electric conductivity. In the present study, we investigate the color-electric conductivity of the quark-gluon plasma (QGP) in the presence of shear viscosity, focusing on the connection between the charge transport and momentum transport. To achieve this goal, we solve the viscous chromohydrodynamic equations obtained from the QGP kinetic theory associated with the distribution function modified by shear viscosity. According to the solved color fluctuations of hydrodynamic quantities, we obtain the induced color current through which the color-electric conductivity is derived. Numerical analysis shows that the conductivity properties of the QGP are mainly demonstrated by the longitudinal part of the color-electric conductivity. Shear viscosity has an appreciable impact on real and imaginary parts of the color-electric conductivity in some frequency regions.

2021, 45(5): 054107. doi: 10.1088/1674-1137/abe9a3

**Abstract:**

Proton-halo breakup behavior in the

2021, 45(5): 054108. doi: 10.1088/1674-1137/abec39

**Abstract:**

The effects of pre-equilibrium emission and secondary decay on the determination of the freeze-out volume are investigated using the isospin-dependent quantum molecular dynamics model accompanied by the statistical decay model GEMINI. Small-mass projectiles and large-mass targets with central collisions are studied at intermediate energies. It is revealed that the proton yields of pre-equilibrium emission are smaller than those of secondary decay. However, the determination of the freeze-out volume from the proton yields is more easily affected by pre-equilibrium emission. Moreover, the percentage of proton yields in the freeze-out stage is found to be approximately 50%.

2021, 45(5): 054109. doi: 10.1088/1674-1137/abec69

**Abstract:**

Fission properties of the actinide nuclei are deduced from theoretical analysis. We investigate potential energy surfaces and fission barriers and predict the fission fragment mass yields of actinide isotopes. The results are compared with experimental data where available. The calculations were performed in the macroscopic-microscopic approximation with the Lublin-Strasbourg Drop (LSD) for the macroscopic part, and the microscopic energy corrections were evaluated in the Yukawa-folded potential. The Fourier nuclear shape parametrization is used to describe the nuclear shape, including the non-axial degree of freedom. The fission fragment mass yields of the nuclei considered are evaluated within a 3D collective model using the Born-Oppenheimer approximation.

2021, 45(5): 055001. doi: 10.1088/1674-1137/abe84b

**Abstract:**

The establishment of a possible connection between neutrino emission and gravitational-wave (GW) bursts is important to our understanding of the physical processes that occur when black holes or neutron stars merge. In the Daya Bay experiment, using the data collected from December 2011 to August 2017, a search was performed for electron-antineutrino signals that coincided with detected GW events, including GW150914, GW151012, GW151226, GW170104, GW170608, GW170814, and GW170817. We used three time windows of ±10, ±500, and ±1000 s relative to the occurrence of the GW events and a neutrino energy range of 1.8 to 100 MeV to search for correlated neutrino candidates. The detected electron-antineutrino candidates were consistent with the expected background rates for all the three time windows. Assuming monochromatic spectra, we found upper limits (90% confidence level) of the electron-antineutrino fluence of (1.13 − 2.44)×10

^{11}cm

^{−2}at 5 MeV to 8.0×10

^{7}cm

^{−2}at 100 MeV for the three time windows. Under the assumption of a Fermi-Dirac spectrum, the upper limits were found to be (5.4 − 7.0)×10

^{9}cm

^{−2}for the three time windows.

2021, 45(5): 055101. doi: 10.1088/1674-1137/abe369

**Abstract:**

Based on the Melnikov method, we investigate chaotic behaviors in the extended thermodynamic phase space for a slowly rotating Kerr-AdS black hole under temporal and spatial perturbations. Our results show that the temporal perturbation coming from a thermal quench of the spinodal region in the phase diagram may cause temporal chaos only when the perturbation amplitude is above a critical value, which involves the angular momentum

*J*. Under the spatial perturbation, however, it is found that spatial chaos always occurs, independent of the perturbation amplitude.

2021, 45(5): 055102. doi: 10.1088/1674-1137/abe36a

**Abstract:**

The collisional Penrose process of massive spinning particles in a rotational Einstein-Gauss-Bonnet (EGB) black hole background is studied. By numerically solving the equations of motion for spinning particles, we find that the energy extraction efficiency increases monotonically with the decrease of the EGB coupling parameter

*s*grows. We also find that the energy extraction efficiency increases with the decrease of the EGB coupling parameter

2021, 45(5): 055103. doi: 10.1088/1674-1137/abe84c

**Abstract:**

We derive an exact solution for a spherically symmetric Bardeen black hole surrounded by perfect fluid dark matter (PFDM). By treating the magnetic charge

*g*and dark matter parameter

*g*and decreases with the dark matter parameter

*a*and magnetic charge

*g*, the Cauchy horizon radius increases while the event horizon radius decreases. Finally, we investigate the energy extraction by the Penrose process in a rotating Bardeen black hole surrounded by PFDM.

2021, 45(5): 055104. doi: 10.1088/1674-1137/abea0d

**Abstract:**

The phase state of dense matter in the intermediate density range (

2021, 45(5): 055105. doi: 10.1088/1674-1137/abeb5e

**Abstract:**

By throwing a test charged particle into a Reissner-Nordstrom (RN) black hole, we test the validity of the first and second laws of thermodynamics and the weak cosmic censorship conjecture (WCCC) with two types of boundary conditions: the asymptotically anti-de Sitter (AdS) space and a Dirichlet cavity wall placed in an asymptotically flat space. For the RN-AdS black hole, the second law of thermodynamics is satisfied, and the WCCC is violated for both extremal and near-extremal black holes. For the RN black hole in a cavity, the entropy can either increase or decrease depending on the change in the charge, and the WCCC is satisfied/violated for the extremal/near-extremal black hole. Our results indicate that there may be a connection between the black hole thermodynamics and the boundary condition imposed on the black hole.

**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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