Chinese Physics C

This is the second part of the new evaluation of atomic masses, AME2020. Using least-squares adjustments to all evaluated and accepted experimental data, described in Part I, we derived tables with numerical values and graphs which supersede those given in AME2016. The first table presents the recommended atomic mass values and their uncertainties. It is followed by a table of the influences of data on primary nuclides, a table of various reaction and decay energies, and finally, a series of graphs of separation and decay energies. The last section of this paper provides all input data references that were used in the AME2020 and the NUBASE2020 evaluations.

The NUBASE2020 evaluation contains the recommended values of the main nuclear physics properties for all nuclei in their ground and excited, isomeric (T_1/2$\ge$100 ns) states. It encompasses all experimental data published in primary (journal articles) and secondary (mainly laboratory reports and conference proceedings) references, together with the corresponding bibliographical information. In cases where no experimental data were available for a particular nuclide, trends in the behavior of specific properties in neighboring nuclei were examined and estimated values are proposed. Evaluation procedures and policies that were used during the development of this evaluated nuclear data library are presented, together with a detailed table of recommended values and their uncertainties.

The mass spectra of charmonium are investigated using a Coulomb plus linear (Cornell) potential. Gaussian wave functions in position space as well as in momentum space are employed to calculate the expectation values of potential and kinetic energy respectively. Various experimental states (X(4660)(5³S₁), X(3872)(2³P₁), X(3900)(2¹P₁), X(3915)(2³P₀) and X(4274)(3³P₁) etc.) are assigned as charmonium states. We also study the Regge trajectories, pseudoscalar and vector decay constants, electric and magnetic dipole transition rates, and annihilation decay widths for charmonium states.

We perform a global effective-field-theory analysis to assess the combined precision of Higgs couplings, triple gauge-boson couplings, and top-quark couplings, at future circular e⁺e⁻ colliders, with a focus on runs below the $t\bar{t}$ production threshold. Deviations in the top-quark sector entering as one-loop corrections are consistently taken into account in the Higgs and diboson processes. We find that future lepton colliders running at center-of-mass energies below the $t\bar{t}$ production threshold can still provide useful information on top-quark couplings, by measuring virtual top-quark effects. With rate and differential measurements, the indirect individual sensitivity achievable is better than at the high-luminosity LHC. However, strong correlations between the extracted top-quark and Higgs couplings are also present and lead to much weaker global constraints on top-quark couplings. This implies that a direct probe of top-quark couplings above the $t\bar{t}$ production threshold is also helpful for the determination of Higgs and triple-gauge-boson couplings. In addition, we find that below the ${e}^{+}{e}^{-}\to t\bar{t}h$ production threshold, the top-quark Yukawa coupling can be determined by its loop corrections to all Higgs production and decay channels. Degeneracy with the ggh coupling can be resolved, and even a global limit is competitive with the prospects of a linear collider above the threshold. This provides an additional means of determining the top-quark Yukawa coupling indirectly at lepton colliders.

In this work, we make the first study of electroweak baryogenesis (EWBG) based on the LHC data in the CP-violating next-to-minimal supersymmetric model (NMSSM) where a strongly first order electroweak phase transition (EWPT) is obtained in the general complex Higgs potential. With representative benchmark points which pass the current LEP and LHC constraints, we demonstrate the structure of EWPT for those points and how a strongly first order EWPT is obtained in the complex NMSSM where the resulting gravitational wave production properties are found to be within the reaches of future space-based interferometers like BBO and Ultimate-DECIGO. We further calculate the generated baryon asymmetries where the CP violating sources are (1): higgsino-singlino dominated, (2): higgsino-gaugino dominated or (3): from both sources. It is shown that all three representing scenarios could evade the strong constraints set by various electric dipole moments (EDM) searches where cancellations among the EDM contributions occur at the tree level (higgsino-singlino dominated) or loop level (higgsino-gaugino dominated). The 125 GeV SM like Higgs can be either the second lightest neutral Higgs H₂ or the third lightest neutral Higgs H₃. Finally, we comment on the future direct and indirect probe of CPV in the Higgs sector from the collider and EDM experiments.

The lowest-lying glueballs are investigated in lattice QCD using N_f = 2 clover Wilson fermions on anisotropic lattices. We simulate at two different and relatively heavy quark masses, corresponding to physical pion masses of m_π ∼ 938 MeV and 650 MeV. The quark mass dependence of the glueball masses has not been investigated in the present study. Only the gluonic operators built from Wilson loops are utilized in calculating the corresponding correlation functions. In the tensor channel, we obtain the ground state mass to be 2.363(39) GeV and 2.384(67) GeV at m_π ∼ 938 MeV and 650 MeV, respectively. In the pseudoscalar channel, when using the gluonic operator whose continuum limit has the form of ε_ijk TrB_iD_jB_k, we obtain the ground state mass to be 2.573(55) GeV and 2.585(65) GeV at the two pion masses. These results are compatible with the corresponding results in the quenched approximation. In contrast, if we use the topological charge density as field operators for the pseudoscalar, the masses of the lowest state are much lighter (around 1 GeV) and compatible with the expected masses of the flavor singlet ${\rm{q}}\bar{{\rm{q}}}$ meson. This indicates that the operator ε_ijk TrB_iD_jB_k and the topological charge density couple rather differently to the glueball states and ${\rm{q}}\bar{{\rm{q}}}$ mesons. The observation of the light flavor singlet pseudoscalar meson can be viewed as the manifestation of effects of dynamical quarks. In the scalar channel, the ground state masses extracted from the correlation functions of gluonic operators are determined to be around 1.4-1.5 GeV, which is close to the ground state masses from the correlation functions of the quark bilinear operators. In all cases, the mixing between glueballs and conventional mesons remains to be further clarified in the future.

We propose to deploy limits that arise from different tests of the Pauli Exclusion Principle: i) to provide theories of quantum gravity with experimental guidance; ii) to distinguish, among the plethora of possible models, the ones that are already ruled out by current data; iii) to direct future attempts to be in accordance with experimental constraints. We first review experimental bounds on nuclear processes forbidden by the Pauli Exclusion Principle, which have been derived by several experimental collaborations making use of various detector materials. Distinct features of the experimental devices entail sensitivities on the constraints hitherto achieved that may differ from one another by several orders of magnitude. We show that with choices of these limits, well-known examples of flat noncommutative space-time instantiations of quantum gravity can be heavily constrained, and eventually ruled out. We devote particular attention to the analysis of the κ-Minkowski and θ-Minkowski noncommutative spacetimes. These are deeply connected to some scenarios in string theory, loop quantum gravity, and noncommutative geometry. We emphasize that the severe constraints on these quantum spacetimes, although they cannot rule out theories of top-down quantum gravity to which they are connected in various ways, provide a powerful limitation for those models. Focus on this will be necessary in the future.

The recent global analysis of three-flavor neutrino oscillation data indicates that the normal neutrino mass ordering is favored over the inverted one at the 3σ level, and the best-fit values of the largest neutrino mixing angle θ₂₃ and the Dirac CP-violating phase δ are located in the higher octant and third quadrant, respectively. We show that all these important issues can be naturally explained by the μ-τ reflection symmetry breaking of massive neutrinos from a superhigh energy scale down to the electroweak scale owing to the one-loop renormalization-group equations (RGEs) in the minimal supersymmetric standard model (MSSM). The complete parameter space is explored for the first time in both the Majorana and Dirac cases, by allowing the smallest neutrino mass m₁ and the MSSM parameter tanβ to vary within their reasonable regions.

We develop a comprehensive dynamical framework, CIBJET, to calculate on an event-by-event basis the dependence of correlations between soft (p_T < 2 GeV) and hard (p_T > 10 GeV) azimuthal flow angle harmonics on the color composition of near-perfect QCD fluids produced in high energy nuclear collisions at RHIC and LHC. CIBJET combines consistently predictions of event-by-event VISHNU2+1 viscous hydrodynamic fluid fields with CUJET3.1 predictions of event-by-event jet quenching. We find that recent correlation data favor a temperature dependent color composition including bleached chromo-electric q(T)+g(T) components and an emergent chromo-magnetic degrees of freedom m(T) consistent with non-perturbative lattice QCD information in the confinement/deconfinement temperature range.

In this study, Higgs and Z boson associated production with subsequent decay is attempted in the framework of alternative left-right model, which is motivated by superstring-inspired E₆ model at CEPC and future linear colliders. We systematically analyze each decay channel of Higgs with theoretical constraints and latest experimental methods. Due to the mixing of scalars in the Higgs sector, charged Higgs bosons can play an essential role in the phenomenological analysis of this process. Even though the predictions of this model for the signal strengths of this process are close to the standard model expectations, it can be distinct under high luminosity.

We discuss almost degenerate vector dark matter and dark photonsinduced from the hidden $S U(2)_H$ gauge sector, where it is spontaneously broken by the vacuum expectation value of $S U(2)_H$ doublet. Kinetic mixing between $S U(2)_H$ and $U(1)_Y$ gauge fields can be generated by introducing a dimension six operator realizing dark photon interactions. In estimating relic density, we focus on the process in which dark matter annihilates into dark photons and search for the region of dark matter mass and gauge coupling realizing observed relic density. We then discuss constraints from dark photon physics, thermalization of dark sector, and direct detection of dark matter. It is then found that constraints from direct detection experiments give us the strongest upper limits on the dark photon interactions.

The production of heavy-quark (HQ) jets is a new area that addresses the mass effect of jet quenching in heavy-ion physics. This paper presents a theoretical study of HQ jet yield suppression in Pb+Pb collisions at the Large Hadron Collider (LHC) and focuses on the energy loss of HQ jets produced by different mechanisms. The p+p baseline is provided by the generator simulation of high-energy reactions of particles (SHERPA), and the jet-medium interactions are described by the SHELL transport model, which considers the elastic and inelastic partonic energy loss in the quark-gluon plasma (QGP). In p+p collisions, our numerical results indicate that the HQ jets from gluon splitting ($g \rightarrow Q$-jet) are the dominant contribution at high $p_T$, displaying more dispersive structures than the HQ-initiated ($Q \rightarrow Q$-jet). In nucleus-nucleus collisions, our calculations were consistent with the inclusive and b-jet $R_{AA}$ recently measured by the ATLAS collaboration, revealing a remarkable manifestation of the mass effect of jet energy loss. As a result of the dispersive substructure, the $g \rightarrow Q$-jet loses more energy than the $Q \rightarrow Q$-jet in the QGP. Due to the significant contribution of $g \rightarrow c$-jet, the $R_{AA}$ of c-jet is comparable or even smaller than that of inclusive jet. To experimentally distinguish the $g \rightarrow Q$-jet and $Q \rightarrow Q$-jet, we propose event selection strategies based on their topological features and test their performances. By isolating the $c \rightarrow c$-jet, $b \rightarrow b$-jet, and the jets initiated by heavy quarks, we predicted that the order of their $R_{AA}$ are in line with the mass hierarchy of energy loss. Future measurements on the $R_{AA}$ of $Q \rightarrow Q$-jet and $g \rightarrow Q$-jet will provide a unique opportunity for testing the flavor/mass dependence of energy loss at the jet level.

The processes involving leptons plus missing energy (and jets) at lepton colliders (electron–positron and muon colliders) are studied in the leptoquarks plus dark matter (DM) model. We calculate the full next-to-leading order (NLO) corrections, including QCD, EW, and ISR, for heavy DM pair production, followed by the heavy DM cascade decay into stable DM and SM fermions. Large logarithmic effects caused by collinear ISR and EW virtual corrections are emphasized. Moreover, we emphasize that NLO corrections become increasingly significant with higher $\sqrt{s}$. However, for larger NLO corrections at high $\sqrt{s}$, the EW corrections dominate over the QCD corrections. The significance of the signals can be enhanced by applying kinematic cuts. By incorporating the NLO correction factor, the significance of the signal processes could be further improved by approximately 40% and 20% for $\chi_0 b \nu_{\tau}$ and $\chi_0 c \tau$ channels at a 10 TeV muon collider.

Shell closure structures are commonly observed phenomena associated with nuclear charge radii throughout the nuclide chart. Inspired by recent studies demonstrating that the abrupt change can be clearly observed in the charge radii of the scandium isotopic chain across the neutron number N=20, we further review the underlying mechanism of the enlarged charge radii for ⁴²Sc based on the covariant density functional theory. The pairing correlations are tackled by solving the state-dependent Bardeen-Cooper-Schrieffer equations. Meanwhile, the neutron-proton correlation around the Fermi surface derived from the simultaneously unpaired proton and neutron is appropriately considered in describing the systematic evolution of nuclear charge radii. The calculated results suggest that the abrupt increase in charge radii across the N=20 shell closure seems to be improved along the scandium isotopic chain if the strong neutron-proton correlation is properly included.

In this study, we systematically investigate the α decay half-lives of 263 emitters in the $52\leq Z\leq 107$region and clusters ¹⁴C, ²⁰O, ²³Fe, ^24,25,26Ne, ^28,30Mg, and ^32,34Si in the presence of an extended form of the Sextic potential to describe the strong nuclear interaction between the daughter nucleus and cluster in the parent nucleus using the Wentzel-Kramers-Brillouin (WKB) method. We find nuclear potential parameters that explain the decay mechanism for each variety of cluster and show that this form of double-well potential provides an excellent description of the nuclear decay phenomenon. We highlight constraints between the potential parameters and experimental data. Moreover, we emphasize the importance of the coupling parameters of the nuclear potential in the nature of the preformed cluster. The obtained results are compared with experimental and literature data. Our results are in very good agreement with the experimental data.

Axion-like particles (ALPs) produced via the Primakoff process in the cores of Galactic core-collapse supernovae (SNe) could convert into MeV-energy γ rays through interactions with the Milky Way's magnetic field. To evaluate the detection prospects for such signals, we perform sensitivity projections for next-generation MeV telescopes by combining hypothetical instrument responses with realistic background estimates. Our analysis incorporates detailed simulations of the expected ALP flux from nearby SNe, the energy-dependent conversion probability in Galactic magnetic fields, and the telescope's angular/energy resolution based on advanced detector designs. Background components are modeled using data from current MeV missions and extrapolated to future sensitivity regimes.&#xD;&#xD;Our simulations demonstrate that next-generation telescopes with improved effective areas and energy resolution could achieve sensitivity to photon-ALP couplings as low as $g_{a\gamma} \approx 1.26 \times 10^{-13}~\mathrm{GeV}^{-1}$&#xD;for ALP masses $m_a < 10^{-9}~\mathrm{eV}$, surpassing existing constraints from SN 1987A. This results indicate that future MeV missions will probe unexplored regions of ALP parameter space, with conservative estimates suggesting they could constrain $g_{a\gamma}$ values two orders of magnitude below current astrophysical limits. Such observations would provide the most stringent tests to date for axion-like particles as a dark matter candidate in the ultra-light mass regime.

We propose a search strategy at the HL-LHC for a new neutral particle \( X \) that couples to \( W \)-bosons, using the process \( p p \to W^{\pm} X (\to W^{+} W^{-}) \) with a tri-\( W \)-boson final state. Focusing on events with two same-sign leptonic \( W \)-boson decays into muons and a hadronically decaying \( W \)-boson, our method leverages the enhanced signal-to-background discrimination achieved through a machine-learning-based multivariate analysis. Using the heavy photophobic axion-like particle (ALP) as a benchmark, we evaluate the discovery sensitivities on both production cross section times branching ratio \( \sigma(p p \to W^{\pm} X) \times \text{Br}(X \to W^{+} W^{-}) \) and the coupling \( g_{aWW} \) for the particle mass over a wide range of 170–3000 GeV at the HL-LHC with center-of-mass energy \( \sqrt{s} = 14 \, \text{TeV} \) and integrated luminosity \( \mathcal{L} = 3 \, \text{ab}^{-1} \). Our results show significant improvements in discovery sensitivity, particularly for masses above 300 GeV, compared to existing limits derived from CMS analyses of Standard Model (SM) tri-\( W \)-boson production at \( \sqrt{s} = 13 \, \text{TeV} \). This study demonstrates the potential of advanced selection techniques in probing the coupling of new particles to \( W \)-bosons and highlights the HL-LHC's capability to explore the physics beyond the SM. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

In this paper, a feedforward neural network (FNN) approach is employed to optimize three local mass models (GK, GKs, and GK+J). It is found that adding physical quantities related to pairing effect in the input layer can effectively improve the prediction accuracy of local models. For the known masses in AME2012, the FNN reduces the root-mean-square deviation between theory and experiment for the three mass models by 11 keV, 32 keV and 623 keV. Among them, the improvement effect of light mass region with mass number between 16 and 60 is better than that of medium and heavy mass regions. It also has good optimization results when extrapolating AME2012 to AME2020 and the latest measured masses after AME2020. Based on the improved mass data, the separation energies for single- and two-proton (neutron) emissions, and $\alpha$-decay energies are obtained, which agree well with the experiment.

Our previous study [A. H. Al-Ghamdi et al., JTUSCI 16 (2022) 1026] provided a comprehensive analysis of elastic scattering angular distributions (ADs) for the 7Li + 28Si system. This analysis aimed to identify the types of threshold anomaly, specifically normal or breakup, by examining the energy dependence of volume integrals across various interaction potentials. The current study extends this work by investigating the effects of 7Li breakup into a valence particle (triton) orbiting a core (alpha) in the context of a 28Si target, as well as the influence of the 28Si(7Li,α)31P triton transfer reaction on the elastic ADs of the 7Li + 28Si system. The results demonstrate the significance of coupling to the 7Li breakup channel and its subsequent impact on the elastic scattering channel. This strong coupling generates a dynamical polarization potential (DPP), leading to a reduction in potential strengths. A semi-microscopic DPP approach was utilized to model this effect, employing the continuum discretized coupled channels (CDCC) method. Furthermore, the analysis was broadened to assess the effect of the triton stripping reaction 28Si(7Li,α)31P on the elastic 7Li + 28Si scattering.

An invariant-mass spectroscopy has been performed to search for possible resonance states in the loosely-bound neutron-rich 15C nucleus. By detecting alpha and 11Be in coincidence, the excitation energy spectrum for 15C is reconstructed. To estimate physical background from non-resonant prompt alpha particles, a recently proposed weighted event-mixing method with phenomenological reduced weighting at around the alpha-decay threshold is employed to account for the depletion in the prompt alpha's contribution due likely to the Coulomb final-state interactions. A new weighted mixed-event method that focuses on a robust treatment of the Coulomb effect is also proposed. Fitting the spectrum using the background estimated with these two methods, up to two resonance state candidates are proposed. A further experiment with improved statistics and theoretical calculations are called for to confirm these resonance states.