## 2020 Vol. 44, No. 11

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2020, 44(11): 111001. doi: 10.1088/1674-1137/abae4d

**Abstract:**

We investigate mesonic condensation in isospin matter under rotation. Using the two-flavor NJL effective model in the presence of global rotation, we demonstrate two important effects of rotation on its phase structure: a rotational suppression of the scalar-channel condensates, in particular, the pion condensation region; and a rotational enhancement of the rho condensation region with vector-channel condensate. A new phase diagram for isospin matter under rotation is mapped out on the

2020, 44(11): 111002. doi: 10.1088/1674-1137/abb07f

**Abstract:**

We present a universal interpretation of a class of conformal extended standard models that include Higgs portal interactions as realized in low-energy effective theories. The scale generation mechanism in this class (scalegenesis) arises along the (nearly) conformal/flat direction for breaking scale symmetry, where the electroweak symmetry-breaking structure arises similarly as in the standard model. A dynamical origin for the Higgs portal coupling can provide the discriminator for the low-energy “universality class,” to be probed in forthcoming collider experiments.

2020, 44(11): 112001. doi: 10.1088/1674-1137/abaed2

**Abstract:**

Recent progress regarding multiple chiral doublet bands (

2020, 44(11): 113101. doi: 10.1088/1674-1137/abae4c

**Abstract:**

Well-motivated electroweak dark matter is often hosted by an extended electroweak sector that also contains new lepton pairs with masses near the weak scale. In this study, we explore such electroweak dark matter by combining dark matter direct detection experiments and high-luminosity LHC probes of new lepton pairs. Using

*Z*- and

*W*-associated electroweak processes with two or three lepton final states, we show that depending on the overall coupling constant, dark matter masses of up to

2020, 44(11): 113102. doi: 10.1088/1674-1137/abae4e

**Abstract:**

The momentum-space subtraction (MOM) scheme is one of the most frequently used renormalization schemes in perturbative QCD (pQCD) theory. In this paper, we discuss in detail the gauge dependence of the pQCD predictions obtained under the MOM scheme. Conventionally, a renormalization scale ambiguity exists for the fixed-order pQCD predictions; this assigns an arbitrary range and error for the fixed-order pQCD prediction and makes the discussions on the issue of the gauge dependence much more involved. The principle of maximum conformality (PMC) adopts the renormalization group equation to determine the magnitude of the coupling constant; hence, it determines the effective momentum flow of the process, which is independent of the choice of renormalization scale. Thus, no renormalization scale ambiguity exists in PMC predictions. To focus our attention on the MOM scheme's gauge dependence, we first apply the PMC to deal with the pQCD series. As an explicit example, we adopt the Higgs boson decay width

2020, 44(11): 113103. doi: 10.1088/1674-1137/abae4f

**Abstract:**

In this study,

Revisiting nonfactorizable contributions to factorization-forbidden decays of

*B*mesons to charmonium
2020, 44(11): 113104. doi: 10.1088/1674-1137/abae50

**Abstract:**

Motivated by the large rates of

2020, 44(11): 113105. doi: 10.1088/1674-1137/abae53

**Abstract:**

The sensitivity of the direct detection of dark matter (DM) approaches the so-called neutrino floor, below which it is difficult to disentangle the DM candidate from the neutrino background. In this work, we consider the scenario that no DM signals are reported in various DM direct detection experiments and explore whether collider searches could probe DM below the neutrino floor. We adopt several simplified models in which the DM candidate couples to electroweak gauge bosons or leptons in the standard model only through high-dimensional operators. After including the RGE running effect, we investigate the constraints of direct detection, indirect detection, and collider searches. The collider search can probe light DM below the neutrino floor. Particularly, for the effective interaction of

2020, 44(11): 113106. doi: 10.1088/1674-1137/abb080

**Abstract:**

In this article, we study the first radial excited states of the scalar, axialvector, vector, and tensor diquark-antidiquark-type

2020, 44(11): 114001. doi: 10.1088/1674-1137/abadf0

**Abstract:**

We argue that the difference in the yield ratio

2020, 44(11): 114002. doi: 10.1088/1674-1137/abaded

**Abstract:**

Given the insufficient cross-sectional data regarding the 14-MeV-neutron experiment of molybdenum, the vital fusion reactor structural material, and the significant heterogeneities among the reported values, this study examined the (

*n*,2

*n*), (

*n*,α), (

*n*,

*p*), (

*n*,

*d*), and (

*n*,

*t*) reaction cross sections in molybdenum isotopes based on the neutrons produced via a T(

*d*,

*n*)

^{4}He reaction carried out in the Pd-300 Neutron Generator at the China Academy of Engineering Physics (CAEP). A high-resolution gamma-ray spectrometer, which was equipped with a coaxial high-purity germanium detector, was used to measure the product nuclear gamma activities. In addition,

^{27}Al(

*n*,α)

^{24}Na and

^{93}Nb(

*n*,2

*n*)

^{92m}Nb reactions were utilized as the neutron fluence standards. The experimental

^{92}Mo(

*n*,2

*n*)

^{91}Mo,

^{94}Mo(

*n*,2

*n*)

^{93m}Mo,

^{100}Mo(

*n*,2

*n*)

^{99}Mo,

^{98}Mo(

*n*,α)

^{95}Zr,

^{100}Mo(

*n*,α)

^{97}Zr,

^{92}Mo(

*n*,

*p*)

^{92m}Nb,

^{96}Mo(

*n*,

*p*)

^{96}Nb,

^{97}Mo(

*n*,

*p*)

^{97}Nb,

^{98}Mo(

*n*,

*p*)

^{98m}Nb,

^{92}Mo(

*n*,

*d*)

^{91m}Nb, and

^{92}Mo(

*n*,

*t*)

^{90}Nb reaction cross sections were acquired within the 13–15 MeV neutron energy range. Thereafter, we compared and analyzed these obtained cross sections based on the existing IAEA-EXFOR database-derived experimental data, together with evaluation results corresponding to ENDF/B-VIII.0, JEFF-3.3, BROND-3.1, and CENDL-3.1 and the theoretical outcomes acquired through TALYS-1.95 and EMPIRE-3.2.3 (nuclear-reaction modeling tools).

2020, 44(11): 114003. doi: 10.1088/1674-1137/abae4b

**Abstract:**

We systematically construct all the tetraquark currents/operators of

2020, 44(11): 114101. doi: 10.1088/1674-1137/abadee

**Abstract:**

Within an advanced Langevin-hydrodynamics framework coupled to a hybrid fragmentation-coalescence hadronization model, we study heavy flavor quenching and flow in relativistic heavy-ion collisions. We investigate how the initial heavy quark spectrum, the in-medium energy loss and hadronization mechanisms of heavy quarks, the evolution profile of the pre-equilibrium stage, the medium flow, and the temperature dependence of heavy quark diffusion coefficients influence the suppression and elliptic flow of heavy mesons at the RHIC and the LHC. Our results show that the different modeling of initial conditions, pre-equilibrium evolution, and in-medium interactions can individually yield uncertainties of approximately 10-40% in

*D*meson suppression and flow at a low transverse momentum. We also find that proper combinations of collisional versus radiative energy loss, coalescence versus fragmentation in hadronization, and the inclusion of medium flow are the most important factors for describing the suppression and elliptic flow of heavy mesons.

2020, 44(11): 114102. doi: 10.1088/1674-1137/abadf2

**Abstract:**

The cross sections at 5 energy points of the

^{58}Ni(

*n*,

*α*)

^{55}Fe reaction were measured in the 4.50 MeV ≤

*E*

_{n}≤ 5.50 MeV region while those for the

^{60}Ni(

*n*,

*α*)

^{57}Fe and

^{61}Ni(

*n*,

*α*)

^{58}Fe reactions were measured at

*E*

_{n}= 5.00 and 5.50 MeV using the 4.5 MV Van de Graaff accelerator at Peking University. A gridded twin ionization chamber (GIC) was used as the detector, and enriched

^{58}Ni,

^{60}Ni, and

^{61}Ni foil samples were prepared and mounted at the sample changer of the GIC. Three highly enriched

^{238}U

_{3}O

_{8}samples inside the GIC were used to determine the relative and absolute neutron fluxes. The neutron energy spectra were obtained through unfolding the pulse height spectra measured by the EJ-309 liquid scintillator. The interference from the low-energy neutrons and impurities in the samples has been corrected. The present data of the

^{60}Ni(

*n*,

*α*)

^{57}Fe reaction are the first measurement results below 6.0 MeV, and those of the

^{61}Ni(

*n*,

*α*)

^{58}Fe reactions are the first measurement results in the MeV region. The present results have been compared with existing measurements, evaluations, and TALYS-1.9 calculations.

2020, 44(11): 114103. doi: 10.1088/1674-1137/abadf1

**Abstract:**

Proton-induced scattering of

^{238}U nuclei, with spheroidal deformations at beam energies above 100 MeV, is simulated using an improved quantum molecular dynamics model. The angular distribution of the deflected protons is highly sensitive to the orientation of the symmetrical long axis of the target nuclei with respect to the beam direction. As a result, in reverse kinematic reactions, an orientation dichroism effect is predicted, implying that the absorption rate of the

^{238}U beam by a proton target discerns between the parallel and perpendicular orientations of the deformed

^{238}U nuclei.

2020, 44(11): 114104. doi: 10.1088/1674-1137/abae51

**Abstract:**

With

2020, 44(11): 114105. doi: 10.1088/1674-1137/abae52

**Abstract:**

The valence-quark distribution function of the pion has been of interest for decades; particularly, the profile it should adopt when

*x*behavior) has been the subject of a long-standing debate. In the light-front holographic QCD (LFHQCD) approach, this behavior is controlled by the so-called reparametrization function,

*x*profile

*x*exponent of “2” cannot be excluded.

2020, 44(11): 114106. doi: 10.1088/1674-1137/abae55

**Abstract:**

We study the inclusive production of strange vector

2020, 44(11): 114107. doi: 10.1088/1674-1137/abb0dd

**Abstract:**

In this study, the mathematical expression formulated by Bohr for the moment of inertia of even-even nuclei based on the hydrodynamical model is modified. The modification pertains to the kinetic energy of the surface oscillations, including the second and third terms of the

*R*-expansion as well as the first term, which had already been modified by Bohr. Therefore, this work can be considered a continuation and support of Bohr's hydrodynamic model. The procedure yields a Bohr formula to be multiplied by a factor that depends on the deformation parameter. Bohr's (modified) formula is examined by applying it on axially symmetric even-even nuclei with atomic masses ranging between 150 and 190 as well as on some triaxial symmetry nuclei. In this paper, the modification of Bohr's formula is discussed, including information about the stability of this modification and the second and third terms of the

*R*-expansion in Bohr's formula. The results of the calculation are compared with the experimental data and Bohr's results recorded earlier. The results obtained are in good agreement with experimental data, with a ratio of approximately 0.7, and are better than those of the unmodified ones.

2020, 44(11): 115001. doi: 10.1088/1674-1137/abae56

**Abstract:**

The

^{12}C+

^{12}C fusion reaction plays a crucial role in stellar evolution and explosions. Its main open reaction channels include

*p*,

*n*, and

^{8}Be. Despite more than a half century of efforts, large differences remain among the experimental data of this reaction measured using various techniques. In this work, we analyze the existing data using a statistical model. Our calculation shows the following: 1) the relative systematic uncertainties of the predicted branching ratios decrease as the predicted ratios increase; 2) the total modified astrophysical

*S*-factors (

*S*

^{*}factors) of the

*p*and

*S*

^{*}factors of their corresponding ground-state transitions and the characteristic

*E*

_{cm }> 4 MeV, while some discrepancies remain at lower energies, suggesting the need for better measurements in the near future. We find that the

*S*

^{*}factor recently obtained from an indirect measurement is inconsistent with the direct measurement value at energies below 2.6 MeV. We recommend upper and lower limits for the

^{12}C+

^{12}C

*S*

^{*}factor based on the existing models. A new

^{12}C+

^{12}C reaction rate is also recommended.

2020, 44(11): 115101. doi: 10.1088/1674-1137/abadef

**Abstract:**

We investigate whether the new horizon first law still holds in

Cosmic acceleration caused by the extra-dimensional evolution in a generalized Randall-Sundrum model

2020, 44(11): 115102. doi: 10.1088/1674-1137/abadec

**Abstract:**

We investigate an

2020, 44(11): 115103. doi: 10.1088/1674-1137/abae54

**Abstract:**

A numerical study has indicated that there exists a relation between the quasinormal modes and the Davies point for a black hole. In this paper, we analytically study this relation for charged Reissner-Nordström black holes in asymptotically flat and de Sitter (dS) spacetimes in the eikonal limit, under which the quasinormal modes can be obtained from the null geodesics using the angular velocity

*T*in the

*T*-

*T*-

**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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