Precision Atmospheric Neutrino Oscillation Measurements with IceCube DeepCore

冰立方中微子天文台深埋在南极极地冰盖中，是世界上最大、最灵敏的高能中微子望远镜。在过去的几年里，冰立方已经发现了能量达到PeV尺度的天体物理学中微子，它的DeepCore扩展已经通过测量能量低至大约5 GeV的大气中微子来测量粒子物理学的基本参数。在这个项目的过程中，该小组将继续改进事件的模拟和重建，以提高能量分辨率和确定中微子到达探测器的方向，并实施一般性改进以减少干扰背景。为各级年轻物理学家提供参与粒子天体物理学的机会，特别强调鼓励妇女和代表性不足群体的参与。此外，PI创立并继续担任物理和天文学妇女（PAW）学生小组的教师导师。PAW为公开讨论女性面临的挑战及其解决方案提供了一个论坛，为开始攻读物理学的本科生和研究生女性提供了一个指导计划，通过外展活动提高了当地女性在科学领域的知名度，并在友好的环境中提供了网络和职业发展机会。DeepCore位于冰立方阵列的底部中心，得益于其无与伦比的数百万吨基准体积和周围冰立方模块的可用性，可以否决大气μ子背景事件，大大提高了中微子的信噪比。DeepCore已被用于测量μ -中微子的消失和τ -中微子的出现，以及大气电子中微子的通量，其能量比以前的观测高一个数量级，其不确定性可与世界上目前最好的测量相媲美。有了这个奖项，宾夕法尼亚州立大学冰立方小组将继续利用DeepCore数据来回答中微子物理的基本问题，重点是更好更快的事件重建和更有效的背景抑制，以改进其对tau中微子标准化的测量，以更高的精度确定Delta (m_23)^2和theta_23，并减少这些和其他类似分析的系统误差。它还将继续为使用冰立方和DeepCore的中微子提供强有力的支持，以促进通过总部位于宾夕法尼亚州立大学的AMON网络对多信使天体物理源的实时搜索。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Embedded deep in the Antarctic polar ice cap, the IceCube Neutrino Observatory is the world's largest and most sensitive high energy neutrino telescope. In the past few years, IceCube has discovered neutrinos of astrophysical origin at energies reaching the PeV scale, and its DeepCore extension has performed measurements of fundamental parameters in particle physics through the measurement of atmospheric neutrinos at energies as low as roughly 5 GeV. Within the course of this project the group will pursue improvements in the simulation and reconstruction of events to sharpen the energy resolution and the identification of the direction from which the neutrinos reach the detector as well as implement general improvements to reduce the interfering background. Opportunities are provided for young physicists at all levels to become involved in particle astrophysics, with a particular emphasis on encouraging participation among women and underrepresented groups. In addition, the PI founded and continues to serve as the faculty mentor to the Physics and Astronomy Women (PAW) student group. PAW provides a forum for open discussion of the challenges facing women as well as their solutions, runs a mentoring program for starting undergraduate and graduate women in physics, increases the local visibility of women in science through outreach activities, and provides networking and professional development opportunities in a friendly environment. DeepCore, situated at the bottom center of the IceCube array, benefits from its unmatched multi-megaton fiducial volume and the availability of surrounding IceCube modules to veto atmospheric muon background events, greatly enhancing the neutrino signal-to-noise ratio. DeepCore has been used to measure muon-neutrino disappearance and tau-neutrino appearance, as well as the flux of atmospheric electron neutrinos, at energies an order of magnitude higher than previous observations, and with uncertainties that are comparable to the world's best current measurements. With this award, the Penn State IceCube group will continue to exploit the DeepCore data to answer fundamental questions of neutrino physics, focusing on better and faster event reconstruction and more effective background rejection to improve its measurement of the tau neutrino normalization, to determine Delta (m_23)^2 and theta_23 with greater precision, and to reduce systematic errors for these and other similar analyses. It will also continue to provide strong support for the use of neutrinos from IceCube and DeepCore to facilitate real-time searches for multi-messenger astrophysical sources via the AMON network headquartered at Penn State.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.