最轻核低能电弱过程的精确理论处理不仅在核物理{ \it per se}的范围内,而且从天体物理和粒子物理的观点来看,都具有重要的现实意义。我简要介绍一下这一领域最近取得的显著进展。
英文摘要:
The accurate theoretical treatment of low-energy electro-weak processes in lightest nuclei is of great current importance not only in the context of nuclear physics {\it per se} but also from the astrophysical and particle-physics viewpoints. I give a brief survey of the recent remarkable progress in this domain.
The development of the chiral dynamics based description of nuclear electroweak currents is reviewed. Gerald E. (Gerry) Brown's role in basing theoretical nuclear physics on chiral Lagrangians is emphasized. Illustrative examples of the successful description of electroweak observables of light nuclei obtained from chiral effective field theory are presented.
The past decade has witnessed tremendous progress in the theoretical and computational tools that produce our understanding of nuclei. A number of microscopic calculations of nuclear electroweak structure and reactions have successfully explained the available experimental data, yielding a complex picture of the way nuclei interact with electroweak probes. This achievement is of great interest from the pure nuclear-physics point of view. But it is of much broader interest too, because the level of accuracy and confidence reached by these calculations opens up the concrete possibility of using …
Nuclear Many-Body Theory of Electroweak Interactions with Nuclei at Intermediate Energies
将文献\cite{GNO97}中的核包容电子模型的准弹性(QE)贡献推广到研究电弱荷电电流(CC)引起的中能核反应,为将来的中微子振荡实验提供理论依据.长程核关联(RPA),最终状态相互作用(FSI)和库仑修正包括在模型中。RPA的相关性在整个中微子能量范围内发挥着至关重要的作用,高达500兆电子伏,在这项工作中研究。通过元素周期表和反应$^{12}$ C $(ν_μ,μ^-)X$和$^{12}$ C $(ν_e,e^-)X$阈值附近的包容μ子捕获的预测也给出了。
Since the pioneering work of Weinberg, Chiral Effective Field Theory ($χ$EFT) has been widely and successfully utilized in nuclear physics to study many-nucleon interactions and associated electroweak currents. Nuclear $χ$EFT has now developed into an intense field of research and is applied to study light to medium mass nuclei. In this contribution, we focus on the development of electroweak currents from $χ$EFT and present applications to selected nuclear electroweak observables.
Elastic electron scattering has been used to paint the most accurate picture of the proton distribution in atomic nuclei. Spurred by new experimental developments, it is now possible to gain valuable insights into the neutron distribution using exclusively electroweak probes. Our goal is to assess the information content and complementarity of the following three electroweak experiments in constraining the neutron distribution of atomic nuclei: (a) parity violating elastic electron scattering, (b) coherent elastic neutrino nucleus scattering, and (c) elastic electron scattering of unstable nuc…
Electroweak form factors of large nuclei as BPS skyrmions
Universidad de Santiago de Compostela(圣地亚哥德孔波斯特拉大学);Instituto Galego de Física de Altas Enerxias (IGFAE)(加利西亚高能物理研究所);University of the Basque Country UPV/EHU(巴斯克地区大学);Universidade de Vigo(维戈大学)
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。
Probing the electroweak structure of nuclei with rare atoms and molecules
Johns Hopkins University(约翰斯·霍普金斯大学);Princeton University(普林斯顿大学);Massachusetts Institute of Technology(麻省理工学院);TRIUMF(特利昂夫);McGill University(麦吉尔大学);Weizmann Institute of Science(魏茨曼科学研究所)
We have applied the extended factorization scheme to investigate the electroweak pion production on nuclei. The ANL-Osaka model, which was obtained by analyzing the data of $πN$, $γN$, $N(e,e'π)$ and $N(ν,μ\,π) $ reactions up to invariant mass $W=$ 2 GeV, is used to generate the matrix elements of current operators relevant to pion-production off the nucleon. Medium effects on the $Δ$ (1232) component of meson-exchange current are included by using a $Δ$-nucleus potential determined from the previous $Δ$-hole model studies of pion-nucleus reactions. Nuclear correlations in the initial target s…
In recent years, the combination of precise quantum Monte Carlo (QMC) methods with realistic nuclear interactions and consistent electroweak currents, in particular those constructed within effective field theories (EFTs), has lead to new insights in light and medium-mass nuclei, neutron matter, and electroweak reactions. This compelling new body of work has been made possible both by advances in QMC methods for nuclear physics, which push the bounds of applicability to heavier nuclei and to asymmetric nuclear matter and by the development of local chiral EFT interactions up to next-to-next-to…
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
Current and future electron and neutrino scattering experiments will be greatly aided by a better understanding of the role played by short-range correlations in nuclei. Two-body physics, including nucleon-nucleon correlations and two-body electroweak currents, is required to explain the body of experimental data for both static and dynamical nuclear properties. In this work, we focus on examining nucleon-nucleon correlations from a chiral effective field theory perspective and provide a comprehensive set of new variational Monte Carlo calculations of one- and two-body densities and momentum d…
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.
Over the last decade, numerical solutions of Quantum Chromodynamics (QCD) using the technique of lattice QCD have developed to a point where they are beginning to connect fundamental aspects of nuclear physics to the underlying degrees of freedom of the Standard Model. In this review, the progress of lattice QCD studies of nuclear matrix elements of electroweak currents and beyond-Standard-Model operators is summarized, and connections with effective field theories and nuclear models are outlined. Lattice QCD calculations of nuclear matrix elements can provide guidance for low-energy nuclear r…
Analytic decomposition of two-body electroweak processes with left-hand cuts
Ruhr-Universität Bochum(波鸿鲁尔大学);University of California, Berkeley(加州大学伯克利分校);Lawrence Berkeley National Laboratory(劳伦斯伯克利国家实验室);CSIC‐Universitat de Valéncia(西班牙国家研究委员会-瓦伦西亚大学)