Nuclear, Particle, and Weak Interaction Physics of the Big Bang and Stellar Collapse

这个项目的智力价值在于它的主要目标：探索原子核和中微子的基本物理，一方面利用核物理学和中微子物理学之间令人兴奋的协同作用，另一方面利用天体物理环境的动力学/核合成。中微子和强相互作用物理/原子核的相互关联物理是当前理论的核心，用于早期宇宙中轻核和重子/轻子数的起源，恒星坍缩事件中重核的起源，超新星动力学，甚至可能是暗物质/能量问题。核物理学和核天体物理学站在当前两大科学趋势的交汇点：(1)正在进行的实验驱动的中微子物理学革命；(2)观测天文学，特别是宇宙学的能力最近取得了惊人的进步。这代表了一个巨大的机会，通过它们的相互联系来推进基本中微子/核物理学和天体物理学和宇宙学。本项目所支持的工作旨在利用这一机会。事实上，在过去的三个资助周期中，PI和他的研究生已经发现了一些基本弱相互作用/中微子/核物理与天体物理学前沿之间的联系，在早期宇宙物理学中，引力坍缩物理学，核合成，特别是中微子之间的可能联系？风味转化和动力学/核合成。事实证明，这里是培养研究生（9年内获得7名博士学位，其中5人获得终身或终身职位）和本科生（6名REU本科生）的良好基地。这个项目将使优秀学生的持续培养成为可能。再加上PI的研讨会/推广和出版物，这构成了该项目在科学产品之外的更广泛影响。有争议的是，中微子的质量平方差和真空混合角（除了13）现在已经被测量出来了。该项目的一个关键目标是评估和计算这些新知识对早期宇宙物理模型、引力坍缩和核合成的影响。中微子的一些特性，如违反cp的相位（es）和13仍然无法测量。这里的目标将是评估这些量在天体物理环境中的作用，并着眼于约束条件。最终，中微子质量和混合光谱的全部范围，特别是关于右手态仍然是一个谜。因为宇宙学参数（例如，来自宇宙微波背景（CMB）的同位素）和中微子性质受到如此严格的限制，例如，在正在进行的mini-BooNE实验中，一个积极的结果可能表明存在一个轻SU(2)单线态“无菌”中微子，它与活性物质混合。这也可能表明存在一个大的净轻子数，并呼吁对现有的恒星坍缩、重元素核合成、中微子在暗物质/能量中的作用以及重子数的起源等模型进行彻底的改革。最近对超贫金属光环恒星的观测使我们对r过程有了新的认识，这对现有的模型提出了挑战（例如，对于核质量为100的恒星，太阳系的丰度模式似乎是普遍的）。PI和他的学生将指导分析和数值计算：(1)从大爆炸核合成和轻子数产生/毁灭/极限、CMB衍生中微子质量极限、超新星激波再加热、r过程核合成、超新星中微子信号等方面了解早期宇宙中双活和双无菌通道中微子风味变换；并且所有的重点都是洞察新发现的非线性中微子-中微子前向散射“背景”势在有源中微子/反中微子转换通道中的不动点解；(2)进一步研究了恒星坍缩/重元素核合成过程中的中微子-核相互作用，包括热核退激成中微子对和中微子俘获诱导裂变，以及高温核配分函数与核内弱强度分布关系的一致性处理；(3)通过更好地了解早期宇宙中QCD时代的物理，从未来的x射线观测，以及这些粒子在超新星爆炸后中子星中的影响，特别是控制这些重态脱相干产生的中微子势随时间演变的方式，对无菌中微子暗物质进行更好的约束；(4)探索动态中微子质量生成在宇宙学中的作用；(5)裂变循环的高中子过量r过程核合成研究。

The intellectual merit of this project rests on its principal goal: to probe the fundamental physics of nuclei and neutrinos by exploiting the exciting synergy between nuclear physics and neutrino physics on the one hand, and the dynamics/nucleosynthesis of astrophysical environments on the other. The interrelated physics of neutrinos and strong interaction physics/nuclei is at the heart of current theories for the origin of the light nuclei and the baryon/lepton numbers in the early universe, the origin of the heavy nuclei in stellar collapse-based events, the dynamics of supernovae, and potentially even the dark matter/energy problems. Nuclear physics and nuclear astrophysics stand at the contact point of two great current trends in science: (1) the ongoing experimentally driven revolution in neutrino physics; and (2) the startling recent advances in the capabilities of observational astronomy, especially in cosmology. This represents a tremendous opportunity for advancing both fundamental neutrino/nuclear physics and astrophysics and cosmology through their interconnection. The work supported by this project will aim at exploiting this opportunity. In fact, the PI and his graduate students over the last three funding cycles have discovered a number of these connections between fundamental weak interaction/neutrino/nuclear physics and the frontiers of astrophysics, in early universe physics, the physics of gravitational collapse, nucleosynthesis, and especially the possible connections between neutrino ?avor transformation and dynamics/nucleosynthesis. This has proven to be an excellent training ground for graduate students (7 PhD's in 9 years, all of whom have positions in nuclear physics research, and 5 have tenured or tenure track positions) and undergraduates (6 REU undergraduates). This project will enable the continuing training of excellent students. Coupled with the PI's seminars/outreach and publications, this constitutes the broader impact of this project beyond the scientific product. Arguably, the mass-squared differences and vacuum mixing angles (save for 13) of the neutrinos are now measured. A key goal of this project is to assess and calculate the impact of this new knowledge on models for the physics of the early universe, gravitational collapse, and nucleosynthesis. Some neutrino properties, like the CP-violating phase(es) and 13 remain unmeasured. A goal here will be to assess the role of these quantities in astrophysical environments with an eye toward constraints. Ultimately, the full extent of the neutrino mass and mixing spectrum, especially regarding right-handed states remains mysterious. Because the cosmological parameters (e.g., as derived from the Cosmic Microwave Background (CMB) anisotopies) and neutrino properties are so tightly constrained, a positive result in the on-going mini-BooNE experiment, for example, could signal the existence of a light SU(2) singlet 'sterile' neutrino which mixes with active species. This might also signal the existence of a large net lepton number(s) as well as call for a radical overhall of existing models for stellar collapse, heavy element nucleosynthesis, the role of neutrinos in dark matter/energy, and the origin of the baryon number. Observations of Ultra Metal Poor halo stars recently have given us new insight into the r-process which challenge existing models (e.g., the solar system abundance pattern seems to be universal for nuclear masses 100). The PI and his students will direct analytic and numerical calculations toward: (1) an understanding of active-active and active-sterile channel neutrino flavor transformation in the early universe as regards big bang nucleosynthesis and lepton number generation/destruction/limits, CMB derived neutrino mass limits, supernova shock re-heating, r-process nucleosynthesis, the supernova neutrino signal, and all with emphasis on insight into the newly discovered fixed point solution for the nonlinear neutrino-neutrino forward scattering 'background' potential in the active-active neutrino/antimeutrino conversion channel; (2) a further study of neutrino-nucleus interactions in stellar collapse/heavy element nucleosynthesis, including de-excitation of hot nuclei into neutrino pairs and neutrino capture-induced fission, as well as a consistent treatment of the relationship between the high temperature nuclear partition function and the weak strength distribution in nuclei; (3) studies directed toward better constraints on sterile neutrino dark matter from better knowledge of the physics of the QCD epoch in the early universe, from future x-ray observatories, and from the effects of these particles in post-supernova explosion neutron stars, especially the way in which the neutrino potentials which the govern de-coherence production of these heavy states evolve with time; (4) exploring the role of dynamical neutrino mass generation in cosmology; (5) studies of high neutron excess r-process nucleosynthesis with fission cycling.