We have been evaluated some observables of n-d systems by using pionless Effective Field Theory(\EFTNoPion) and insertion of the three-body force up to next-to-next to leading order(N$^2$LO). The evaluated data has been compared with experimental and the three-nucleon calculation of the total cross section with modern realistic two- and three-nucleon forces AV18/UrbIX potential models calculations.
We present a determination of optical potentials using the double-folding method based on chiral effective field theory nucleon-nucleon interactions at next-to-next-to-leading order combined with dispersion relations to constrain the imaginary part. This approach is benchmarked on $^{16}$O--$^{16}$O collisions, and extended to the $^{12}$C--$^{12}$C and $^{12}$C--$^{16}$O cases. Predictions derived from these potentials are compared to data for elastic scattering at energies up to 1000 MeV, as well as for fusion at low energy. Without adjusting parameters, excellent agreement with experiment i…
We take a new look at $^{6}\textrm{He}$ halo nucleus and set up a halo effective field theory at low energies to calculate the charge form factor of ${}^{6}\textrm{He}$ system with resonant P-wave interaction. P-wave Lagrangian has been introduced and the charge form factor of ${}^{6}\textrm{He}$ halo nucleus has been obtained at Leading-Order. In this study, the mean-square charge radius of ${}^{6}\textrm{He}$ nucleus relative to ${}^{4}\textrm{He}$ core and the root-mean-square (r.m.s) charge radius of ${}^{6}\textrm{He}$ nucleus have been estimated as $\langle r_{E}^{2}\rangle=1.408\; \text…
On Parity-Violating Three-Nucleon Interactions and the Predictive Power of Few-Nucleon EFT at Very Low Energies
在“无π”有效场论中讨论了核子-氘核（等二重态）系统中强子宇称破坏的三核子相互作用的典型强度。通过分析回路图的表面发散程度，我们得出结论，在主导顺序不需要这样的相互作用。仅有的两个线性独立的宇称违反三核子结构，一个衍生物混合两个S和两个P的半波与同位旋跃迁Δ I = 0或1。由于它们的结构，它们不能吸收任何表面上出现在次领先顺序的发散。这一观察是基于在双核子系统中近似实现维格纳的SU（4）自旋-同位旋对称性，即使包括有效射程修正。因此，宇称破坏的三核子相互作用只出现在次领先阶之外。这保证了理论的重整化，而不引入新的，未知的耦合常数，并允许直接提取宇称破坏两核子相互作用的三核子实验。
We present a description of the break-up of halo nuclei in peripheral nuclear reactions by coupling a model of the projectile motivated by Halo Effective Field Theory with a fully dynamical treatment of the reaction using the Dynamical Eikonal Approximation. Our description of the halo system reproduces its long-range properties, i.e., binding energy and asymptotic normalization coefficients of bound states and phase shifts of continuum states. As an application we consider the break-up of 11Be in collisions on Pb and C targets. Taking the input for our Halo-EFT-inspired description of 11Be fr…
We recently developed a Bayesian framework for parameter estimation in general effective field theories. Here we present selected results from using that framework to estimate parameters with a nucleon-nucleon (NN) potential derived using chiral effective field theory ($χ$EFT): the semi-local NN potential of Epelbaum, Krebs, and Meißner (EKM). There are many NN scattering data, up to high energies, and with rather small errors, so imposing a penalty for unnatural low-energy constants (LECs) usually has a small effect on the fits. In contrast, we have found that including an estimate of higher …
$^{17}$C has three states below the $^{16}$C + $n$ threshold with quantum numbers $J^P=3/2^+,1/2^+,5/2^+$. These states have relatively small neutron separation energies compared to the neutron separation and excitation energies of $^{16}$C. This separation of scales motivates our investigation of $^{17}$C in a Halo effective field theory (Halo EFT) with a $^{16}$C core and a valence neutron as degrees of freedom. We discuss various properties of the three states such as electric radii, magnetic moments, electromagnetic transition rates and capture cross sections. In particular, we give predic…
The parity-violating (PV) nucleon-nucleon ($N\!N$) interaction in the three-nucleon system is investigated using pionless effective field theory ($\mathrm{EFT}(/\!\!\!π)$). This work shows that a next-to-leading order (NLO) PV three-body force is necessary in contradiction with a previous claim [Griesshammer and Schindler in Eur. Phys. J. A 46, 73 (2010)]. Including three-body $P$ to $D$-wave transitions PV three-nucleon observables are calculated to higher energies than previously considered. Using the recent large-$N_{C}$ analysis of the PV $N\!N$ interaction in $\mathrm{EFT}(/\!\!\!π)$ the …
$ np \leftrightarrow dγ$ reactions calculated up to $E_γ=20$ MeV
Institute of Modern Physics, Chinese Academy of Sciences（中国科学院近代物理研究所）；Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University（莫斯科国立大学索别利茨基核物理研究所）
Threshold pion production in proton-proton collisions at NNLO in chiral EFT
反应$NN \to NN π$为手征有效场论在中能区提供了一个很好的实验平台。它挑战了我们对核子-核子散射中第一非弹性通道和强子反应中电荷对称性破缺模式的理解。在我们以前的研究中，我们给出了手征有效场论中包括π介子、核子和$Δ(1232)$自由度在内的s波π介子的π介子产生算符的完整计算.在本文中，我们计算了$pp \to d π^{+}$反应的近阈值截面的基础上现代唯象和手征势核波函数进行卷积的操作。可用的手性$NN$波函数的构造与π介子生产反应中固有的动量传递尺度的截止。因此，动态中程物理学的很大一部分因此被它们切断。另一方面，用唯象波函数评估的NNLO振幅似乎在很大程度上独立于所用的$NN$模型，并对主导的领先阶贡献进行了修正，正如量纲分析所预期的那样。这一结果支持了对π介子产生算符进行分类的计数方案，这是可靠地研究手征抑制中性π介子产生的前提。明确列入的$Δ(1232)$被认为是重要的，但小于预期的，由于取消。
We treat low-energy $^3$He-$α$ elastic scattering in an Effective Field Theory (EFT) that exploits the separation of scales in this reaction. We compute the amplitude up to Next-to-Next-to-Leading Order (NNLO), developing a hierarchy of the effective-range parameters that contribute at various orders. We use the resulting formalism to analyze data for recent measurements at center-of-mass energies of 0.38-3.12 MeV using the SONIK gas target at TRIUMF as well as older data in this energy regime. We employ a likelihood function that incorporates the theoretical uncertainty due to truncation of t…
We use the next-to-leading-order (NLO) amplitude in an effective field theory (EFT) for ${}^3$He + ${}^4$He $\rightarrow {}^7$Be + $γ$ to perform the extrapolation of higher-energy data to solar energies. At this order the EFT describes the capture process using an s-wave scattering length and effective range, the asymptotic behavior of $^7$Be and its excited state, and short-distance contributions to the E1 capture amplitude. We use a Bayesian analysis to infer the multi-dimensional posterior of these parameters from capture data below 2 MeV. The total $S$-factor $S(0)= 0.578^{+0.015}_{-0.016…
Technische Universität Darmstadt（达姆施塔特工业大学）；ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH（极端物质研究所 (EMMI)，GSI 重离子研究中心有限公司）；National Center for Computational Sciences, Oak Ridge National Laboratory（国家计算科学中心，橡树岭国家实验室）；Physics Division, Oak Ridge National Laboratory（物理部，橡树岭国家实验室）；Max-Planck-Institut für Kernphysik（马克斯·普朗克核物理研究所）
We have studied the vacuum and thermal fluctuation energies of a soliton at finite temperatures. First the vacuum energy coming from the Dirac sea is calculated by a summation of the discrete and continuum energy spectrum of the Dirac equation in the background field of a soliton. And all the divergences are removed by the same renormalization scheme at zero temperature. Then the vacuum energy and thermal fluctuation energy at finite temperatures in a temperature dependent soliton background are calculated. And the numerical results are analyzed and discussed.
Particle production in relativistic $pp$($\overline{p}$) and $AA$ collisions at RHIC and LHC energies with Tsallis statistics using the two-cylindrical multisource thermal model
