Supernova relic neutrino detection with neutron tagging

使用中子标记检测超新星遗迹中微子

• 批准号: 2612942
• 金额: --
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2612942
• 关键词: Supernova; relic; neutrino; detection; neutron

When a massive star exhausts all sources of fuel, its existence ends in a core-collapse supernova explosion. This events involve all four forces of nature and, as yet, are not well understood. During the core-collapse, over 99% of the gravitational energy of the star is converted into neutrinos. To date, we have only detected one burst of supernova neutrinos, from SN1987a. Since the neutrinos effectively travel forever, the universe should be filled with an isotropic signal of neutrinos from all of the core-collapse supernovae that have ever exploded. These neutrinos are known as "supernova relic neutrinos" (SRN) and have not yet been observed. The primary SRN interaction is inverse beta decay, in which an electron antineutrino interacts with a free proton to produce a positron and a neutron. The recent loading of gadolinium into the Super-Kamiokande water Cherenkov detector allows the neutron to be detected, in addition to the positron signal. This coincidence tagging is a powerful tool for removing the previously irreducible backgrounds that have prevented SRN detection. During his PhD, the student will work as a member of the Super-Kamiokande collaboration to make a first detection of the SRN. This is the first step towards collecting a high-statistics sample, which can then be used to determine the supernova history of the universe.

当一颗巨大的恒星耗尽所有燃料来源时，其存在以核心爆发的超新星爆炸结束。这一事件涉及自然的所有四种力量，至今还没有很好地理解。在核心崩溃期间，恒星的重力超过99％被转化为中微子。迄今为止，我们只从SN1987A检测到了一阵超新星中微子。由于中微子有效地永远旅行，因此宇宙应充满曾经爆炸的所有核心折叠超新星的中微子的各向同性信号。这些中微子被称为“超新星遗物中微子”（SRN），尚未观察到。主要的SRN相互作用是β衰变，其中电子抗神经抗体与游离质子相互作用以产生正电子和中子。除了正电子信号之外，最近将Gadolinium载入超级Kamiokande Water Cherenkov检测器还可以检测到中子。这种巧合标记是删除以前不可还原背景的强大工具，这些背景阻止了SRN检测。在他的博士学位期间，该学生将担任Super-Kamiokande合作的成员，以首次检测SRN。这是收集高统计样本的第一步，然后可以将其用于确定宇宙的超新星历史。