## 2020 Vol. 44, No. 3

Display Method: |

2020, 44(3): 031001. doi: 10.1088/1674-1137/44/3/031001

**Abstract:**

We emphasize that it is extremely important for future neutrinoless double-beta (

2020, 44(3): 031002. doi: 10.1088/1674-1137/44/3/031002

**Abstract:**

A symmetry-preserving continuum approach to the two valence-body bound-state problem is used to calculate the valence, glue and sea distributions within the pion; unifying them with, inter alia, electromagnetic pion elastic and transition form factors. The analysis reveals the following momentum fractions at the scale

2020, 44(3): 033001. doi: 10.1088/1674-1137/44/3/033001

**Abstract:**

The research on geoneutrinos is a new interdisciplinary subject involving particle experiments and geo-science. Potassium-40 (

^{40}K) decays contribute roughly to 1/3 of the radiogenic heat of the Earth, which is not yet accounted for by experimental observation. Solar neutrino experiments with liquid scintillators have observed uranium and thorium geoneutrinos and are the most promising experiments with regard to low-background neutrino detection. In this study, we present the new concept of using liquid-scintillator Cherenkov detectors to detect the neutrino-electron elastic scattering process of

^{40}K geoneutrinos. Liquid-scintillator Cherenkov detectors using a slow liquid scintillator achieve this goal with both energy and direction measurements for charged particles. Given the directionality, we can significantly suppress the dominant intrinsic background originating from solar neutrinos in conventional liquid-scintillator detectors. We simulated the solar- and geo-neutrino scatterings in the slow liquid scintillator detector, and implemented energy and directional reconstructions for the recoiling electrons. We found that

^{40}K geoneutrinos can be detected with three-standard-deviation accuracy in a kiloton-scale detector.

2020, 44(3): 033101. doi: 10.1088/1674-1137/44/3/033101

**Abstract:**

Neutron-antineutron (

2020, 44(3): 033102. doi: 10.1088/1674-1137/44/3/033102

**Abstract:**

Tensor reduction is of considerable importance in calculations of multi-loop amplitudes, and the projection method is one of the most popular approaches for tensor reduction. However, the projection method can be problematic when applied to amplitudes with massive fermions, due to the inconsistency between helicity and chirality. We propose an extended projection method for reducing the loop amplitude which contains a fermion chain with two massive spinors. The extension is achieved by decomposing one of the massive spinors into two massless spinors, the “null spinor” and the “reference spinor”. The extended projection method can be effectively applied in all processes, including the production of massive fermions. We present the tensor reduction for a virtual

*Z*boson decaying into a top-quark pair as a demonstration of our approach.

2020, 44(3): 033103. doi: 10.1088/1674-1137/44/3/033103

**Abstract:**

In order to make a further confirmation of the assignments of the excited bottom and bottom-strange mesons

2020, 44(3): 033104. doi: 10.1088/1674-1137/44/3/033104

**Abstract:**

Calculation of disconnected quark loops in lattice QCD is very time consuming. Stochastic noise methods are generally used to estimate these loops. However, stochastic estimation gives large errors in the calculations of disconnected diagrams. We use the symmetric multi-probing source (SMP) method to estimate the disconnected quark loops, and compare the results with the

2020, 44(3): 034001. doi: 10.1088/1674-1137/44/3/034001

**Abstract:**

The cross-section data of the

^{85}Rb(

*n*, 2

*n*)

^{84}Rb reaction have been measured with the neutron energies of 12 MeV to 19.8 MeV using the activation technique and the relative method. The

^{85}Rb samples were irradiated on the surface of a two-ring orientation assembly with neutrons produced from the

^{3}H(

*d*,

*n*)

^{4}He reaction at the 5SDH-2 1.7-MV Tandem accelerator in China. Theoretical model calculations were performed with the TALYS-1.9 code. The present data were compared with previously obtained experimental data and the available evaluated data.

2020, 44(3): 034101. doi: 10.1088/1674-1137/44/3/034101

**Abstract:**

We achieved a set of

^{9}Be global phenomenological optical model potentials by fitting a large experimental dataset of the elastic scattering observable for target mass numbers from 24 to 209. The obtained

^{9}Be global optical model potential was applied to predict elastic-scattering angular distributions and total reaction cross-sections of

^{8,10,11}B projectiles. The predictions are made by performing a detailed analysis comparing with the available experimental data. Furthermore, these elastic scattering observables are also predicted for some lighter targets outside of the given mass number range, and reasonable results are obtained. Possible physical explanations for the observed differences are also discussed.

2020, 44(3): 034102. doi: 10.1088/1674-1137/44/3/034102

**Abstract:**

Nuclear masses of even-even nuclei with the proton number

2020, 44(3): 034103. doi: 10.1088/1674-1137/44/3/034103

**Abstract:**

We present a new method for solving the probability distribution for baryons, antibaryons, and mesons at the hadronization of the constituent quark and antiquark system. The hadronization is governed by the quark combination rule in the quark combination model developed by the Shandong Group. We employ the method of the generating function to derive the outcome of the quark combination rule, which is significantly simpler and easier to generalize than the original method. Furthermore, we use the formula of the quark combination rule and its generalization to study the property of the multiplicity distribution of net-protons. Taking a naive case of quark number fluctuations and correlations at hadronization, we calculate ratios of multiplicity cumulants of final-state net-protons and discuss the potential applicability of the quark combination model by studying hadronic multiplicity fluctuations and the underlying phase transition property in relativistic heavy-ion collisions.

2020, 44(3): 034104. doi: 10.1088/1674-1137/44/3/034104

**Abstract:**

We propose a forward method based on PYTHIA6.4 to study the jet properties in ultra-relativistic

*pp*collisions. In the forward method, the partonic initial states are first generated with PYTHIA6.4 and then hadronized in the Lund string fragmentation model, and finally the hadronic jets are constructed from the created hadrons. Jet properties calculated with the forward method for

*pp*collisions at

2020, 44(3): 034105. doi: 10.1088/1674-1137/44/3/034105

**Abstract:**

The formation of charged pion condensate in anti-parallel electromagnetic fields and in the presence of the isospin chemical potential is studied in the two-flavor Nambu–Jona-Lasinio model. The method of Schwinger proper time is extended to explore the quantities in the off-diagonal flavor space, i.e. the charged pion. In this framework,

2020, 44(3): 034106. doi: 10.1088/1674-1137/44/3/034106

**Abstract:**

The multi-particle states and rotational properties of the two-particle bands in

2020, 44(3): 034107. doi: 10.1088/1674-1137/44/3/034107

**Abstract:**

We investigate the

2020, 44(3): 034108. doi: 10.1088/1674-1137/44/3/034108

**Abstract:**

We study the two-color QCD matter with two fundamental quark flavors using the chiral perturbation theory and the Nambu-Jona-Lasinio (NJL) model. The effective Lagrangian is derived in terms of mesons and baryons,

*i.e.*diquarks. The low lying excitations lie in the extended

2020, 44(3): 035101. doi: 10.1088/1674-1137/44/3/035101

**Abstract:**

We explore a new relativistic anisotropic solution of the Einstein field equations for compact stars based on embedding class one condition. For this purpose, we use the embedding class one methodology by employing the Karmarkar condition. Employing this methodology, we obtain a particular differential equation that connects both the gravitational potentials

2020, 44(3): 035102. doi: 10.1088/1674-1137/44/3/035102

**Abstract:**

We study the Joule-Thomson expansion of the regular black hole in an anti-de Sitter background, and obtain the inversion temperature for the Bardeen-AdS black hole in the extended phase space. We investigate the isenthalpic and inversion curves for the Bardeen-AdS black hole in the

*T*-

*P*plane and find that the intersection points between them are exactly the inversion points discriminating the heating from the cooling process. The inversion curve for the regular(Bardeen)-AdS black hole is not closed and there is only a lower inversion curve, in contrast to the Van der Waals fluid. Most importantly, we find that the ratio between the minimum inversion temperature and the critical temperature for the regular(Bardeen)-AdS black hole is 0.536622, which is larger than any known ratio for the singular black hole. The large ratio for the Bardeen-AdS black hole may be due to the repulsive de Sitter core near the origin of the regular 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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