## 2022 Vol. 46, No. 5

Display Method: |

2022, 46(5): 051001. doi: 10.1088/1674-1137/ac567e

**Abstract:**

The observation of the light hybrid candidate

*SU*(3) flavor octet and singlet mixing is non-negligible and apparently deviates from the flavor ideal mixing. Because only signals for one isoscalar

2022, 46(5): 053101. doi: 10.1088/1674-1137/ac4975

**Abstract:**

We discuss a linear seesaw model with a field content as minimum as possible, introducing a modular

2022, 46(5): 053102. doi: 10.1088/1674-1137/ac4bcc

**Abstract:**

We perform a lattice QCD calculation of the

*σ*. Potential improvements of the lattice calculation in the future are also discussed.

2022, 46(5): 053103. doi: 10.1088/1674-1137/ac4c9f

**Abstract:**

In this paper, we calculate the

2022, 46(5): 053104. doi: 10.1088/1674-1137/ac4cb5

**Abstract:**

The contributions for the kaon pair from the intermediate states

*ρ*mesons should be of great importance in the

*B*decays. Moreover, these quasi-two-body decays are CKM-favored, and the relevant branching ratios are predicted to be in the order of

*B*meson decays are considerable according to the total three-body branching fractions presented by Belle. Therefore, the decays

2022, 46(5): 053105. doi: 10.1088/1674-1137/ac4e7c

**Abstract:**

A gauge-invariant model is constructed for the

*t*-channel

*K*and

*s*-channel nucleon exchange, and interaction current, the

*s*-channel nucleon resonance exchanges are included in constructing the reaction amplitudes to describe the data. It is found that the contributions from the

*s*-channel

*t*-channel

*K*exchange contributes significantly, while the contributions from the

*t*-channel

*s*-channel nucleon exchange are ultimately negligible. The contributions from the

*s*-channel

2022, 46(5): 053106. doi: 10.1088/1674-1137/ac500e

**Abstract:**

*Z*-boson is related to the mixing of

*Z*and the mass of

*Z*mixing. The angular distributions change significantly with some special beam polarization compared with the unpolarized condition.

2022, 46(5): 053107. doi: 10.1088/1674-1137/ac5010

**Abstract:**

We extend the unitary groups beyond the

2022, 46(5): 054001. doi: 10.1088/1674-1137/ac488b

**Abstract:**

Two low-lying unbound states in

^{16}C are investigated by deuteron inelastic scattering in inverse kinematics. Besides the 2

*n*knockout reaction, a new resonant state at 6.89 MeV is observed for the first time. The inelastic scattering angular distributions of these two states are well reproduced by the distorted-wave Born approximation (DWBA) calculation with an

*l*= 1 excitation. In addition, the spin-parities of the unbound states are discussed and tentatively assigned based on shell model calculations using the modified YSOX interaction.

2022, 46(5): 054002. doi: 10.1088/1674-1137/ac4a5a

**Abstract:**

The cross sections of the

^{121}Sb

^{120}Sb

^{m}and

^{123}Sb

^{122}Sb reactions were measured at 12.50, 15.79 and 18.87 MeV neutron energies relative to the standard

^{27}Al

^{24}Na monitor reaction using neutron activation and offline γ-ray spectrometry. Irradiation of the samples was performed at the BARC-TIFR Pelletron Linac Facility, Mumbai, India. The quasi-monoenergetic neutrons were generated via the

^{7}Li

^{121}Sb and

^{123}Sb isotopes was also performed within 14–15 MeV neutron energies using various systematic formulae. This work helps to overcome discrepancies in Sb data and illustrate a better understanding of pre-equilibrium emission in the

2022, 46(5): 054003. doi: 10.1088/1674-1137/ac4ca0

**Abstract:**

New cross sections of the

^{183}W(

*n,α*)

^{180m}Hf,

^{186}W(

*n,d**)

^{185}Ta,

^{182}W(

*n,p*)

^{182}Ta,

^{184}W(

*n,p*)

^{184}Ta,

^{182}W(

*n*,2

*n*)

^{181}W,

^{184}W(

*n*,

*α*)

^{181}Hf, and

^{186}W(

*n*,

*α*)

^{183}Hf reactions were measured in the neutron energy range of 13.5-14.8 MeV via the activation technique to improve the database and resolve discrepancies. Monoenergetic neutrons in this energy range were produced via the T(

*d*,

*n*)

^{4}He reaction on a solid Ti-T target. The activities of the irradiated monitor foils and samples were measured using a well-calibrated high-resolution HPGe detector. Theoretical calculations of the excitation functions of the seven nuclear reactions mentioned above in the neutron energies from the threshold to 20 MeV were performed using the nuclear theoretical model program TALYS-1.9 to aid new evaluations of cross sections on tungsten isotopes. The experimental data obtained were analyzed and compared with that of previous experiments conducted by other researchers, and with the evaluated data available in the five major evaluated nuclear data libraries of IAEA (namely ENDF/B-VIII.0 or ENDF/B-VII.0, JEFF-3.3, JENDL-4.0u+, CENDL-3.2, and BROND-3.1 or ROSFOND-2010), and the theoretical values acquired using TALYS-1.9 nuclear-reaction modeling tools. The new cross section measurements agree with those of some recent experiments and theoretical excitation curves at the corresponding energies. The consistency of the theoretical excitation curves based on TALYS-1.9 with these experimental data is better than that of the evaluated curves available in the five major nuclear data libraries of IAEA.

2022, 46(5): 054101. doi: 10.1088/1674-1137/ac4b5c

**Abstract:**

We apply the recently proposed RMF (BCS)* ansatz to study the charge radii of the potassium isotopic chain up to

^{52}K. It is shown that the experimental data can be reproduced rather well, qualitatively similar to the Fayans nuclear density functional theory, but with a slightly better description of the odd–even staggerings (OES). Nonetheless, both methods fail for

^{50}K and to a lesser extent for

^{48,52}K. It is shown that if these nuclei are deformed with a

^{50}K.

2022, 46(5): 054102. doi: 10.1088/1674-1137/ac4c3a

**Abstract:**

The generalized liquid-drop model (GLDM) with the microscopic shell correction from relativistic Hartree-Fock (RHF) calculations is used to explore the

*α*-decay of superheavy nuclei. The known nuclei with

*α*-decay agree with the experimental data better than those from the GLDM with the shell correction in the Weizs

*α*-decay is investigated. It is determined that the

*α*-decay lifetime for the unknown superheavy nuclei with

*α*-decay half-lives according to the neutron number is similar to the trends of the values from the GLDM calculation without shell correction as well as the universal decay law (UDL) formula. Comparably, the RHF shell correction depresses (raises) the

*α*-decay lifetime for most nuclei with

*α*-decay is dominant in the superheavy nuclei

2022, 46(5): 054103. doi: 10.1088/1674-1137/ac4ee8

**Abstract:**

Inspired by the recent observation of a very narrow state, called

2022, 46(5): 054104. doi: 10.1088/1674-1137/ac4ee9

**Abstract:**

Balitsky-Kovchegov equations in projectile and target rapidity representations are analytically solved for fixed and running coupling cases in the saturation domain. Interestingly, we find that the respective analytic

*S*-matrices in the two rapidity representations have almost the same rapidity dependence in the exponent in the running coupling case, which provides a method to explain why the equally good fits to HERA data were obtained when using three different Balitsky-Kovchegov equations formulated in the two representations. To test the analytic outcomes, we solve the Balitsky-Kovchegov equations and numerically compute the ratios between these dipole amplitudes in the saturation region. The ratios are close to one, which confirms the analytic results. Moreover, the running coupling, collinearly-improved, and extended full collinearly-improved Balitsky-Kovchegov equations are used to fit the HERA data. We find that all of them provide high quality descriptions of the data, and the

2022, 46(5): 054105. doi: 10.1088/1674-1137/ac500d

**Abstract:**

Naturally occurring

*α*emitters with extremely long half-lives are investigated using the latest experimental data. Within the time-dependent perturbation theory,

*α*decay with a rather narrow width is treated as a quasi-stationary problem by dividing the potential between the

*α*particle and daughter nucleus into a stationary part and a perturbation. The experimental

*α*decay half-lives of seven available long-lived

*α*emitters with

*α*decay half-lives of twenty naturally occurring nuclei are provided, namely,

*α*decay with low decay energies and extremely long decay half-lives. In particular, the candidates

2022, 46(5): 054106. doi: 10.1088/1674-1137/ac500f

**Abstract:**

In this paper, the

*r*-process). It is found that the

2022, 46(5): 055101. doi: 10.1088/1674-1137/ac4704

**Abstract:**

The Large High Altitude Air Shower Observatory (LHAASO) has reported the measurement of photons with high energies of up to 1.42 PeV from twelve gamma-ray sources. We are concerned with the implications of the LHAASO data on the fate of Lorenz symmetry at such high energy levels; thus, we consider the interaction between gamma rays and photons in the cosmic microwave background (CMB) and compute the optical depth, mean free path, and survival probability of photons from these gamma-ray sources. Employing the threshold value predicted by standard special relativity, the lowest survival probability for observed gamma ray photons is found to be approximately 0.60, which is fairly high and implies that abundant photons with energies above the threshold may reach the Earth without Lorentz symmetry violation. We conclude that it is unreasonable to argue that Lorentz symmetry would be violated using current observations at the LHAASO.

2022, 46(5): 055102. doi: 10.1088/1674-1137/ac4b5b

**Abstract:**

The properties of strange quark matter and the structures of (proto-)strange stars are studied within the framework of a baryon density-dependent quark mass model, where a novel quark mass scaling and self-consistent thermodynamic treatment are adopted. Our results indicate that the perturbative interaction has a significant impact on the properties of strange quark matter. It is determined that the energy per baryon increases with temperature, while the free energy decreases and eventually becomes negative. At fixed temperatures, the pressure at the minimum free energy per baryon is zero, suggesting that the thermodynamic self-consistency is preserved. Furthermore, the sound velocity

*v*in quark matter approaches the extreme relativistic limit (

*D*and perturbation parameter

*C*, the tendency for

*v*to approach the extreme relativistic limit at high density is slightly weakened. For (proto-)strange stars, the novel quark mass scaling can accommodate massive proto-strange stars with their maximum mass surpassing twice the solar mass by considering the isentropic stages along the star evolution line, where the entropy per baryon of the star matter is set to be 0.5 and 1 with the lepton fraction

2022, 46(5): 055103. doi: 10.1088/1674-1137/ac4cab

**Abstract:**

The measurement of gravitational waves produced by binary black-hole mergers at the Advanced LIGO has encouraged extensive studies on the stochastic gravitational wave background. Recent studies have focused on gravitational wave sources made of the same species, such as mergers from binary primordial black holes or those from binary astrophysical black holes. In this paper, we study a new possibility – the stochastic gravitational wave background produced by mergers of one primordial black hole and one astrophysical black hole. Such systems are necessarily present if primordial black holes exist. We study the isotropic gravitational wave background produced through the history of the universe. We find it is very challenging to detect such a signal. We also demonstrate that it is improper to treat the gravitational waves produced by such binaries in the Milky Way as a directional stochastic background due to a very low binary formation rate.

2022, 46(5): 055104. doi: 10.1088/1674-1137/ac4df1

**Abstract:**

Understanding the thermodynamic phase transition of black holes can provide deep insights into the fundamental properties of black hole gravity and help to establish quantum gravity. In this work, we investigate the phase transition and its dynamics for the charged EPYM AdS black hole. Through reconstructing Maxwell's equal-area law, we find there exists a high-/low-potential black hole (HPBH/LPBL) phase transition, not only the pure large/small black hole phase transition. The Gibbs free energy landscape (

2022, 46(5): 055105. doi: 10.1088/1674-1137/ac4f4c

**Abstract:**

The extensivity for the thermodynamics of general

*D*-dimensional rotating black holes with or without a cosmological constant can be proved analytically, provided that the effective number of microscopic degrees of freedom and the chemical potential are given respectively as

*G*is the variable Newton constant,

*L*is a constant length scale. In the cases without a cosmological constant, i.e., the Myers-Perry black holes, the physical mass and the intensive variables can be expressed as explicit macro state functions in the extensive variables in a simple and compact form, which allows for an analytical calculation of the heat capacity. The results indicate that the Myers-Perry black holes with zero, one, and

*k*equal rotation parameters are all thermodynamically unstable.

**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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