The intermediate-state interaction and structure of amplitudes of complicated processes in medium (decays, reactions and the $n\bar{n}$ transitions) are studied. It is proposed to use the branching ratio of channels of free-space hadron-nucleon interaction as a test in the construction and verification of the models. The corresponding formulas for the processes in the medium are obtained. The connection between particle self-energy and amplitudes of subprocesses are analyzed as well.
$α$-decay always has enormous impetuses to the development of physics and chemistry, in particular due to its indispensable role in the research of new elements. Although it has been observed in laboratories for more than a century, it remains a difficult problem to calculate accurately the formation probability $S_α$ microscopically. To this end, we establish a new model, i.e., multistep model, and the corresponding formation probability $S_α$ values of some typical $α$-emitters are calculated without adjustable parameters. The experimental half-lives, in particular their irregular behavior a…
The virtual photon theory (VPT), which is based on first-order Coulomb dissociation restricted to the electric dipole ($E1$), has been successfully used to explain the breakup data for several cases. Our aim is to study the role of various higher-order processes that are ignored in the VPT, such as the nuclear breakup, interference between nuclear and Coulomb amplitudes, and multistep breakup processes mainly due to strong continuum-continuum couplings in the breakup of two-body projectiles on a heavy target at both intermediate and higher incident energies. For the purpose of numerical calcul…
We perform a parameter-free calculation for the high-energy proton-nucleus scattering based on the Glauber theory. A complete evaluation of the so-called Glauber amplitude is made by using the factorization of the single-particle wave functions. The multiple-scattering or multistep processes are fully taken into account within the Glauber theory. We demonstrate that proton- $^{12}$C, $^{20}$Ne, and $^{28}$Si elastic and inelastic scattering ($J^π=0^+ \to 2^+$ and $0^+ \to 4^+$) processes are very well described in a wide range of the incident energies from $\sim$50 MeV to $\sim$ 1 GeV. We eval…
The Power Of Effective Field Theories In Nuclei: The Deuteron, NN Scattering and Electroweak Processes
我们展示了如何有效有效的量子场论工作在核物理。利用物理上透明的截断正则化方法,我们研究了最简单的两核子核系统的束缚态和散射态,其动量尺度远小于π介子质量。我们考虑了氘核的所有静态性质、双核子散射相移、热能下的n + p --> d + γ过程和太阳质子聚变过程p + p --> d + e(+)+v(e),并证明了这些都在次领先阶展开中得到了很高的精度描述。我们探讨如何一个“新的”自由度进入一个有效的理论打开和关闭的作用,π介子的拉格朗日。
In this paper, we calculate cross sections for charged-current neutrino-nucleus processes occuring under presupernova conditions. To treat thermal effects we extend self-consistent Skyrme-QRPA calculations to finite temperature by using the formalism of thermo field dynamics. The numerical results are presented for the sample nuclei, $^{56}$Fe and $^{82}$Ge
The competition among reaction processes of a weakly-bound projectile at intermediate times of a slow collision has been unraveled. This has been done using a two-center molecular continuum within a semiclassical, time-dependent coupled-channel reaction model. Dynamical probabilities of elastic scattering, transfer and breakup agree with those derived from the direct integration of the time-dependent Schrödinger equation, demonstrating the usefulness of a two-center molecular continuum for gaining insights into the reaction dynamics of exotic nuclei.
Scattering of Antiprotons by Nuclei (Atoms) in the Range of Low Energies $E\lesssim 10^5$ eV. Mirror Reflection, Diffraction, and Channeling of Antiprotons in Crystals
Effective charged neutrons involved in one- and two- nucleon tunneling processes in heavy ion collisions between superfluid nuclei are expected to emit photons. Although the centroid, width and integrated energy area characterizing the associated gamma-strength functions are rather similar, the corresponding line shapes reflect the thermal equilibrated-like character of the quasiparticle transfer (1n-channel, blackbody spectral functional dependence), and the quantal coherent character of the Cooper pair transfer (2n-channel, Gaussian functional dependence) respectively. The predicted angular …
Astrophysical nucleosynthesis is a family of diverse processes by which atomic nuclei undergo nuclear reactions and decays to form new nuclei. The complex nature of nucleosynthesis, which can involve as many as tens of thousands of interactions between thousands of nuclei, makes it difficult to study any one of these interactions in isolation using standard approaches. In this work, we present a new technique, nucleosynthesis tracing, that we use to quantify the specific role of individual nuclear reaction, decay, and fission processes in relationship to nucleosynthesis as a whole. We apply th…
Role of break-up processes in fusion enhancement of drip-line nuclei at energies below the Coulomb barrier
本文对$^{11}$ Be + $^{208}$ Pb反应进行了真实的耦合道计算,讨论了入射核破碎对亚势垒熔合的影响。我们离散的粒子连续态,这是与破碎过程中,并构造耦合形状因子,这些国家的微观基础上的能量。引入边界条件求解耦合通道方程,从而定义了库仑势垒内完全聚变的通量。结果表明,完全熔合截面显着增强,由于连续态的耦合相比,没有耦合的情况下,在能量低于库仑势垒,而他们被阻碍在势垒以上的能量。
A U.S.-based Electron-Ion Collider will provide the ultimate capability to determine both the structure and properties of nucleons and nuclei, as well as how matter and energy can be transported through a strongly interacting quantum mechanical environment. The production and propagation of long-lived heavy subatomic particles is a unique and critical part of this planned decade-long research program. In these proceedings we report the derivation of all branching processes in nuclei that lead to a modification of semi-inclusive hadron production, jet cross sections, and jet substructure when c…
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,…
The electric dipole moment (EDM) is a very sensitive probe of CP violation beyond the standard model, and it as been measured in many systems such as atoms, neutrons, etc. The EDM of composite systems may be sensitive to several elementary level CP violating processes, but the theoretical evaluations of the CP violation at different physical (atomic, nuclear, hadronic, elementary) hierarchies are required to unveil them. In this context, we are particularly interested in which CP violating processes are enhanced in a given system, or vice versa. In this proceedings contribution, we will give a…
An increasing interest in multinucleon transfer processes in low-energy deep inelastic (damped) collisions of heavy ions appeared in recent years is due, in part, to by the possibility of using them as a method of production of heavy neutron-enriched nuclei. Possible promising projectile-target combinations include nuclei deformed in the ground state (e.g., actinides). Mutual orientations of such the nuclei in the entrance channel of the reaction may significantly influence the reaction dynamics. Available experimental data on multinucleon transfer reactions with statically deformed as well as…
Use of deuteron-induced spallation reactions at intermediate energies has recently been proposed for transmutation of several long-lived fission products (LLFPs). In the design study of a transmutation system using a deuteron primary beam, accurate cross section data of deuteron-induced reactions on the LLFPs are indispensable. Reliable model predictions play an important role in completing the necessary cross section data since currently available experimental data are very limited. Under the circumstances, we have been developing a code system dedicated for deuteron-induced reactions, which …
Various theories beyond the standard model of particle physics predict the existence of baryon number violating processes resulting in nucleon decay. When occurring within an atomic nucleus, such a decay will be followed by secondary decays of the daughter nucleus unless its ground state is directly populated. In this paper, we estimate branching ratios for processes associated with dinucleon decays of the $^{16}$O nucleus. To this end, we use a simple shell model for the ground state of $^{16}$O. For decays from the 1$s_{1/2}$ configuration, which result in highly excited states in the daught…
A clustering aspect is explained for the $^9$Be nucleus in charged-lepton deep inelastic scattering. Nuclear modifications of the structure function $F_2$ are studied by the ratio $R_{\rm EMC} = F_2^A /F_2^D$, where $A$ and $D$ are a nucleus and the deuteron, respectively. In a JLab experiment, an unexpectedly large nuclear modification slope $|dR_{\rm EMC}/dx|$ was found for $^9$Be, which could be related to its clustering structure. We investigated a mean conventional part of a nuclear structure function $F_2^A$ by a convolution description with nucleon momentum distributions calculated by a…
The density distributions of $^{10}$Be and $^{11}$Be nuclei obtained within the quantum Monte Carlo (QMC) model and the generator coordinate method (GCM) are used to calculate the microscopic optical potentials (OPs) and cross sections of elastic scattering of these nuclei on protons and $^{12}$C at energies $E<100$ MeV/nucleon. The real part of the OP is calculated using the folding model with the exchange terms included, while the imaginary part of the OP that reproduces the phase of scattering is obtained in the high-energy approximation (HEA). In this hybrid model of OP the free parameters…