## 2023 Vol. 47, No. 10

Display Method: |

2023, 47(10): 103001. doi: 10.1088/1674-1137/aceee3

**Abstract:**

A new search for two-neutrino double-beta (2

*νββ*) decay of

^{136}Xe to the

^{136}Ba is performed with the full EXO-200 dataset. A deep learning-based convolutional neural network is used to discriminate signal from background events. Signal detection efficiency is increased relative to previous searches by EXO-200 by more than a factor of two. With the addition of the Phase II dataset taken with an upgraded detector, the median 90% confidence level half-life sensitivity of 2

*νββ*decay to the

^{136}Ba is

^{136}Xe exposure of 234.1 kg yr. No statistically significant evidence for 2

*νββ*decay to the

2023, 47(10): 103101. doi: 10.1088/1674-1137/ace820

**Abstract:**

The inclusion of the

**69**, 1 (2018)] and consider the contribution arising from the kaon mass splitting in the kaon loops and latest experimental data. We perform two types of fits (with momentum-independent or momentum-dependent

2023, 47(10): 103102. doi: 10.1088/1674-1137/ace424

**Abstract:**

Axion-like particles (ALPs) are new particles that extend beyond the standard model (SM) and are extensively investigated. When considering ALPs within an effective field theory framework, their couplings with SM particles can be studied independently. It is a daunting task to search for GeV-scale ALPs coupled to muons in collider experiments because their coupling is proportional to the muon mass. However, a recent study by Altmannshofer, Dror, and Gori (2022) highlighted the importance of a four-point interaction,

*W*-

*μ*-

*a*, as well as interactions from the chiral anomaly, whose couplings are not dependent on the muon mass. These interactions provide a new opportunity to explore muonphilic ALPs (

*μ*ALPs) at the GeV scale. We explore various

*μ*ALP production channels at muon colliders with

*μ*ALPs decaying into a pair of muons. In particular, we find that a pair of neutrinos accompanied by a

*μ*ALP is the most effective channel to search for

*μ*ALPs in the electrowek violating (EWV) scenario. In contrast, a photon plus a

*μ*ALP becomes a better channel to search for

*μ*ALPs in the electroweak preserving (EWP) scenario because there is no

*W*-

*μ*-

*a*interaction in this situation. Most importantly, we find that the future bounds for

*μ*ALPs in the EWV scenario are considerably stronger than those in the EWP scenario and the existing bounds for exploring

*μ*ALPs with

2023, 47(10): 103103. doi: 10.1088/1674-1137/ace5a6

**Abstract:**

The new measurement of the

*W*boson mass from the CDF collaboration shows a significant tension with the standard model prediction, which evidences violation of custodial symmetry in the scalar sector. We study the scalar extensions of the standard model, which can be categorized into two classes, the scalar sector with custodial symmetry (Georgi-Machacek model and its generalizations) and the scalar sector without custodial symmetry, and explore how these extensions fit to electroweak precision data and the new CDF

2023, 47(10): 103104. doi: 10.1088/1674-1137/ace821

**Abstract:**

The form factors of

*P*-wave excited charmed mesons (including

2023, 47(10): 103105. doi: 10.1088/1674-1137/ace8f4

**Abstract:**

This study investigates the prospect of discovering strongly interacting gluinos in different multi-lepton channels with lepton multiplicities greater than or equal to 2 at LHC RUN-III, considering several pMSSM scenarios. The effectiveness of the multivariate analysis (MVA) method with the boosted decision tree (BDT) algorithm is explored to obtain a better significance for different models. Promising results are obtained for the 3-lepton channels, indicating that the use of MVA methods can improve the sensitivity of the search for gluinos at LHC RUN-III. The study probes the multi-lepton signatures arising from gluinos via intermediate eweakinos and sleptons at an early stage of the LHC RUN-III. The heavier eweakinos can give rise to three or four lepton signals, in which the squark hierarchy between the

*L*and

*R*types plays a crucial role. The study considers two sets of benchmark points that satisfy all the collider constraints obtained from the LHC RUN-II data. Moreover, these sets of benchmark points are mostly consistent with WMAP/PLANCK data and the muon (

*g*-2) constraint. The corresponding results from the MVA technique demonstrate that, even for an integrated luminosity of 270

*σ*discovery prospect of

2023, 47(10): 103106. doi: 10.1088/1674-1137/ace5a7

**Abstract:**

A feasibility study is performed on the search for vector-like leptons (VLLs) at a muon collider in the context of the "4321 model", an ultraviolet-complete model with rich collider phenomenology and the potential to explain several recent existing

*B*physics measurements or anomalies. Pair production and decays of VLLs lead to an interesting final state topology with multi-jets and multi-tau leptons. In this study, we perform a Monte Carlo investigation with various machine learning techniques and examine the projected sensitivity on VLLs over a wide mass range at a TeV-scale muon collider. We find that a 3 TeV muon collider with only

2023, 47(10): 104101. doi: 10.1088/1674-1137/ace67f

**Abstract:**

The recently proposed microscopic shell-model version of the Bohr-Mottelson (BM) collective model is considered in more detail in the coordinate representation. The latter possesses a clear and transparent physical meaning, which reveals several features of the new version of the collective model missed in the previous formulation. The relationship to the original BM model is considered, along with the relationships between the different limiting submodels of the microscopic version of the BM model, which closely resemble the relationships of the original Wilets-Jean and rotor models. The kinematically correct many-particle wave functions of the microscopic version of the BM model, conserving the experimentally observed integrals of motion, are shown to consist of collective irrotational-flow and intrinsic components

2023, 47(10): 104102. doi: 10.1088/1674-1137/ace81d

**Abstract:**

We study the relation between chiral and

2023, 47(10): 104103. doi: 10.1088/1674-1137/acee55

**Abstract:**

We discuss current attempts to employ the modified potential cluster model to describe the available experimental data on the

^{13}B(

*n*,

*γ*

_{0+1})

^{14}B total cross-sections. The estimated results of the

*M*1 and

*E*1 transitions from the

*n*

^{13}B scattering states to the ground and first excited states of

^{14}B are presented. The 1

^{st}resonance at

*E*

_{x}= 1. 275 MeV (1

^{+}) is revealed in both the cross-section and reaction rate. Within the variation in the asymptotic constant, a thermal cross-section interval of 5.1 – 8.9 mb is proposed. Based on the theoretical total cross-sections at energies of 0.01 eV to 5 MeV, we calculate the reaction rate in the temperature range of 0.01 to 10

*T*

_{9}. The ignition

*T*

_{9}values of the

^{13}B(

*n*,

*γ*

_{0+1})

^{14}B reaction depending on a neutron number density

^{22}cm

^{−3}are determined. The radiative neutron capture reaction rates on the boron

^{10-13}B and carbon

^{12-14}С isotopes are compared.

2023, 47(10): 104104. doi: 10.1088/1674-1137/acea21

**Abstract:**

We study the experimental and theoretical fusion reactions of compound nuclei synthesized using different projectile-target systems, among which at least one projectile/target nucleus is spherical. The first part of this study analyses the fusion cross sections obtained using different projectile-target combinations in the synthesis of polonium (Po), thorium (Th), and nobelium (No). In the second part of this study, we suggest the fusion reaction to synthesize the superheavy element

*Z*= 122. We select three nuclei, polonium (Po), thorium (Th), and nobelium (No), which are synthesized using various projectile-target combinations. We also investigate fusion reactions such as

*n*)

*Z*= 122.

2023, 47(10): 104105. doi: 10.1088/1674-1137/acf036

**Abstract:**

Vorticities in heavy-ion collisions (HICs) are supposed to induce spin alignment and polarization phenomena of quarks and mesons. In this work, we analyze the spin alignment of vector mesons

*ϕ*and

*ρ*induced by rotation from quark dynamics in the framework of the Nambu-Jona-Lasinio (NJL) model. The rotating angular velocity induces mass splitting of spin components for vector

2023, 47(10): 104106. doi: 10.1088/1674-1137/aceee1

**Abstract:**

The maximum entropy method (MEM) and Gaussian process (GP) regression, which are both well-suited for the treatment of inverse problems, are used to reconstruct net-baryon number distributions based on a finite number of cumulants of the distribution. Baryon number distributions across the chiral phase transition are reconstructed. It is deduced that with the increase of the order of cumulants, distribution in the long tails, i.e., far away from the central number, would become increasingly important. We also reconstruct the distribution function based on the experimentally measured cumulants at the collision energy

2023, 47(10): 104107. doi: 10.1088/1674-1137/acee56

**Abstract:**

The method of

*Q*-cumulants is a powerful tool for studying the fine details of azimuthal anisotropies in high energy nuclear collisions. This paper presents a new method, based on mathematical induction, to evaluate the analytical form of high-order

*Q*-cumulants. The capability of this method is demonstrated via a toy model that uses the elliptic power distribution to simulate the anisotropic emission of particles, quantified in terms of Fourier flow harmonics

2023, 47(10): 104108. doi: 10.1088/1674-1137/ace9c4

**Abstract:**

The special property of the actinide mass region is that nuclei belonging to this group are radioactive and undergo different ground state processes, such as alpha decay, cluster radioactivity (CR), heavy particle radioactivity (HPR), and spontaneous fission (SF). In this study, the probable radioactive decay modes of the heavy mass region (

*Z*= 89−102) are studied within the framework of the preformed cluster model (PCM). In the PCM, the radioactive decay modes are explored in terms of the preformation probability (

*P*) at the turning point

*R*

*R*

*Q*-value dependent turning point (

*Q*)). Then, using the (

*Q*)) relation, the decay half-lives are computed, and the calculated results are compared with the available theoretical and experimental data. The isotopical trend of

*P*is studied with respect to the mass number of the parent and daughter nucleus, respectively. The CR and HPR channels are also explored, and a comparison of calculated data is conducted with the available literature. Comparative analysis of the fragmentation potential and preformation probability is carried out for alpha decay and SF. The mass distribution of the nuclei is studied as a function of fragment mass (

*A*

2023, 47(10): 105101. doi: 10.1088/1674-1137/ace522

**Abstract:**

Future space-based gravitational-wave detectors will detect gravitational waves with high sensitivity in the millihertz frequency band, providing more opportunities to test theories of gravity than ground-based detectors. The study of quasinormal modes (QNMs) and their application in gravity theory testing have been an important aspect in the field of gravitational physics. In this study, we investigate the capability of future space-based gravitational wave detectors, such as LISA, TaiJi, and TianQin, to constrain the dimensionless deviating parameter for Einstein-dilaton-Gauss-Bonnet (EdGB) gravity with ringdown signals from the merger of binary black holes. The ringdown signal is modeled by the two strongest QNMs in EdGB gravity. Considering time-delay interferometry, we calculate the signal-to-noise ratio of different space-based detectors for ringdown signals to analyze their capabilities. The Fisher information matrix is employed to analyze the accuracy of parameter estimation, with particular focus on the dimensionless deviating parameter for EdGB gravity. The impact of the parameters of gravitational wave sources on the estimation accuracy of the dimensionless deviating parameter is also studied. We find that the constraint ability of EdGB gravity is limited because the uncertainty of the dimensionless deviating parameter increases with a decrease in the dimensionless deviating parameter. LISA and TaiJi offer more advantages in constraining the dimensionless deviating parameter to a more accurate level for massive black holes, whereas TianQin is more suited to less massive black holes. The Bayesian inference method is used to perform parameter estimation on simulated data, which verifies the reliability of the conclusion.

2023, 47(10): 105102. doi: 10.1088/1674-1137/ace8f5

**Abstract:**

In this study, we take the mass, electric charge, hair parameter, and cosmological constant of five-dimensional de Sitter hairy spacetime as the state parameters of the thermodynamic system, and when these state parameters satisfy the first law of thermodynamics, the equivalent thermodynamic quantities of spacetime and the Smarr relation of five-dimensional de Sitter hairy spacetime are obtained. Then, we study the thermodynamic characteristics of the spacetime described by these equivalent thermodynamic quantities and find that de Sitter hairy spacetime has a phase transition and critical phenomena similar to those of van de Waals systems or charged AdS black holes. It is shown that the phase transition point of de Sitter hairy spacetime is determined by the ratio of two event horizon positions and the cosmic event horizon position. We discuss the influence of the hair parameter and electric charge on the critical point. We also find that the isochoric heat capacity of the spacetime is not zero, which is consistent with the ordinary thermodynamic system but differs from the isochoric heat capacity of AdS black holes, which is zero. Using the Ehrenfest equations, we prove that the critical phase transition is a second order equilibrium phase transition. Research on the thermodynamic properties of five-dimensional de Sitter hairy spacetime lays a foundation for finding a universal de Sitter spacetime thermodynamic system and studying its thermodynamic properties. Our universe is an asymptotically dS spacetime, and the thermodynamic characteristics of de Sitter hairy spacetime will help us understand the evolution of spacetime and provide a theoretical basis to explore the physical mechanism of the accelerated expansion of the universe.

2023, 47(10): 105103. doi: 10.1088/1674-1137/ace81e

**Abstract:**

The paper extends basic Einstein–Hilbert action by incorporating an invariant derived from a specific contraction between the Einstein tensor and energy momentum tensor. This represents a non–minimal coupling between the space–time geometry and matter fields. The fundamental Einstein–Hilbert action is extended by considering a generic function

2023, 47(10): 105104. doi: 10.1088/1674-1137/ace9c3

**Abstract:**

This paper investigates the feasibility of using a Li-Baker detector based on a modulated Gaussian beam to detect gravitational waves in the GHz band. The first-order perturbation photon fluxes (PPF, signal of the detector) and the background photon fluxes (BPF, main noise of the detector), which vary with time, and the transverse distance are calculated. The results show that their propagation directions and energy densities are much different in some areas. Apart from BPF, we also consider two other important noises: diffraction noise and shot noise. In the simulation, it is found that the diffraction noise and shot noise are both lower than the signal level. Meanwhile, the main noise (BPF) can be eliminated when the receiving screen is located in certain special transverse areas where the BPF direction is opposite to that of PPF. Thus, the signal to noise ratio (SNR) obtained using our detection method can reach up to

2023, 47(10): 105105. doi: 10.1088/1674-1137/acf489

**Abstract:**

The strong gravitational lensing of a regular and rotating magnetic black hole in non-minimally coupled Einstein-Yang-Mills theory is studied. We find that, with the increase of any characteristic parameters of this black hole, such as the rotating parameter

*a*, magnetic charge

*q*and EYM parameter

*λ*, the angular image position

*s*increase. The results will degenerate to that of the Kerr case, RN case with magnetic charge and Schwarzschild case when we take some specific values for the black hole parameters. The results also show that, due to the small influence of magnetic charge and EYM parameters, it is difficult for current astronomical instruments to tell this black hole apart from a General Relativity one.

**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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Cover Story

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- Cover Story (Issue 3, 2024) | First measurement of the ground-state mass of 22Al helpsto evaluate the ab-initio theory
- Cover Story (Issue 2, 2024) | Quark/gluon taggers light the way to new physics
- Cover story (Issue 6, 2023) ï½Joint constraints on cosmological parameters using future multi-band gravitational wave standard siren observations
- Cover Story (Issue 5, 2023) | Production and decay of polarized hyperon-antihyperon pairs