Improved parametrization of the unified model for alpha decay and alpha capture

冷非吸积中子星的状态方程统一化：布鲁塞尔-蒙特利尔泛函。V. 核子密度分布参数化的改进

Unified equations of state for cold nonaccreting neutron stars with Brussels-Montreal functionals. V. Improved parametrization of the nucleon density distributions

本文针对中子星内壳层和意面幔层计算，提出两种改进的核子密度分布参数化方案，在BSk24泛函下比原方案获得更低ETF能量并更准确再现平衡密度分布，同时揭示了高密度区域意面相结构的变化。

Improved empirical parametrizations of the $γ^\ast N \to N(1535)$ transition amplitudes and the Siegert's theorem

Some empirical parametrizations of the $γ^\ast N \to N(1535)$ transition amplitudes violates the Siegert's theorem, that relates the longitudinal and the transverse amplitudes, in the pseudo-threshold limit (nucleon and resonance at rest). In the case of the electromagnetic transition from the nucleon (mass $M$) to the resonance $N(1525)$ (mass $M_R$), the Siegert's theorem is sometimes expressed by the relation $|{\bf q}| A_{1/2}= λS_{1/2}$ in the pseudo-threshold limit, when the photon momentum $|{\bf q}|$ vanishes, and $λ= \sqrt{2} (M_R -M)$. In this article, we argue that the Siegert's the…

包含离心势的分析穿透概率：改进的用于α衰变半衰期的Buck--Merchant--Perez模型

Analytical penetration probability including the centrifugal potential: An improved Buck--Merchant--Perez model for alpha-decay half-lives

研究推导含离心势的α衰变穿透公式，开发改进BMP模型，其核势深度用四参数公式表示。该模型提升了α衰变半衰期预测精度，还用于预测特定区域未测核半衰期，为实验研究提供定量基准。

超重核α衰变半衰期中的非局域效应研究：基于XGB回归模型

Nonlocality Effect in the Alpha decay half-lives of superheavy nuclei with XGBRegressor

本文基于两势方法框架，利用XGB回归模型优化非局域参数，改进了超重核α衰变半衰期计算方法，使RMS偏差降低74.8%，并预测了142个超重核的α衰变半衰期，三种模型结果高度一致。

Improved Nearside-Farside Method for Elastic Scattering Amplitudes

A simple technique is described that provides an improved nearside-farside (NF) method for elastic scattering amplitudes. The technique, involving the novel resummation of a Legendre partial wave series, reduces the importance of unphysical contributions to NF subamplitudes, which can arise in more conventional NF decompositions. Detailed applications are made to a strong absorption model and to a ^{16}O + ^{16}O optical potential at E_{lab} = 145 MeV. We also discuss ^{16}O + ^{16}O at E_{lab} = 480, 704, 1120 MeV, and alpha + ^{12}C, alpha + ^{40}Ca, both at E_{lab} = 1370 MeV.

具有色散约束的$ππ$散射全局参数化：超越S0波

Global parametrizations of $ππ$ scattering with dispersive constraints: Beyond the S0 wave

本文提出了直至1.8 GeV的$ππ$散射S2、P、D、F和G分波新全局参数化，结合更新的S0波，不仅重现了先前色散分析，还改进了对P波数据、非弹性及色散关系的满足，并在1.6 GeV以上采用简单无约束拟合。

Improved empirical parametrizations of the $γ^\ast N \to Δ(1232)$ and $γ^\ast N \to N(1520)$ helicity amplitudes and the Siegert's theorem

In the nucleon electroexcitation reactions, $γ^\ast N \to R$, where $R$ is a nucleon resonance ($N^\ast$), the electric amplitude $E$, and the longitudinal amplitude $S_{1/2}$, are related by $E \propto \fracω{|{\bf q}|}S_{1/2}$, at the pseudo-threshold limit ($|{\bf q}| \to 0$), where $ω$ and $|{\bf q}|$ are respectively the energy and the magnitude of three-momentum of the photon. The previous relation is usually refereed as the Siegert's theorem. The form of the electric amplitude, defined in terms of the transverse amplitudes $A_{1/2}$ and $A_{3/2}$, and the explicit coefficients of the re…

Renormalization Group Improved Gap Equation for Color Superconductors

The renormalization group is used to resum leading logarithmic contributions of the form alpha_s^{n+1} beta_0^n log^n (Delta/mu) to the gap equation appropriate for high density QCD. The scale dependence of the strong coupling constant alpha_s increases the gap by a factor of exp(33/16 (pi^2/4 - 1)) ~ 20 in the small coupling limit.

Quantum design using a multiple internal reflections method in a study of fusion processes in the capture of alpha-particles by nuclei

A high precision method to determine fusion in the capture of $α$-particles by nuclei is presented. For $α$-capture by $^{40}{\rm Ca}$ and $^{44}{\rm Ca}$, such an approach gives (1) the parameters of the $α$--nucleus potential and (2) fusion probabilities. This method found new parametrization and fusion probabilities and decreased the error by $41.72$ times for $α+ ^{40}{\rm Ca}$ and $34.06$ times for $α+ ^{44}{\rm Ca}$ in a description of experimental data in comparison with existing results. We show that the sharp angular momentum cutoff proposed by Glas and Mosel is a rough approximation,…

Further explorations of the alpha-particle optical model potential at low energies for the mass range A=45-209

The recent high-precision measurements of alpha-particle induced reaction data below the Coulomb barrier (B) make possible the understanding of limits and possible improvement of a previous optical model potential (OMP) for alpha-particles on nuclei within the mass number range 45<A<209 [M. Avrigeanu et al., Phys. Rev. C 82, 014606 (2010)]. An updated version of this potential is given in the present work concerning mainly an increased surface imaginary potential depth well below B for A>130. Moreover, underestimation of reaction cross sections for well-deformed nuclei is removed by using ~7% …

alpha-nucleus potentials for the neutron-deficient p nuclei

alpha-nucleus potentials are one important ingredient for the understanding of the nucleosynthesis of heavy neutron-deficient p nuclei in the astrophysical gamma-process where these p nuclei are produced by a series of (gamma,n), (gamma,p), and (gamma,alpha) reactions. I present an improved alpha-nucleus potential at the astrophysically relevant sub-Coulomb energies which is derived from the analysis of alpha decay data and from a previously established systematic behavior of double-folding potentials.

Cross section measurement of the 144Sm(alpha,n)147Gd reaction for studying the alpha-nucleus optical potential at astrophysical energies

Nuclear reactions involving alpha particles play an important role in various astrophysical processes such as the gamma-process of heavy element nucleosynthesis. The poorly known low-energy alpha-nucleus optical (AOMP) potential is a key parameter to estimate the rates of these reactions. The AOMP can be tested by measuring the cross section of alpha-scattering as well as alpha-induced reactions. Low energy elastic alpha-scattering on 144Sm has recently been measured with high precision. The aim of the present work was to complement that work by measuring the (a,n) cross sections on 144Sm at l…

Comment on Constraints on the Low-Energy E1 Cross Section of 12C(alpha,gamma)16O from the Beta-Delayed Alpha Spectrum of 16N

We dispute the alteration by Azuma et al. of the energy calibration of the Mainz('71) data on the beta-delayed alpha-particle emission of $^{16}N$ as well as the very justification of the recalibration. We use the unaltered data to observe a pronounced disagreement between the TRIUMF('94) and Mainz('71) data sets on both the high and low energy sides of the primary peak (at 2.36 MeV) of the $^{16}N$ alpha-spectrum. We cannot support the dismissal of the Mainz('71) spectrum by the TRIUMF collaboration and emphasize the need to include it in R-matrix fits. We discuss the need for new improved da…