Search for Dark Matter with PICO

用 PICO 寻找暗物质

• 批准号: SAPPJ-2016-00025-1
• 负责人: Krauss, Carsten
• 金额: $ 7.16万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Project
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=616838
• 关键词: Search; Dark; Matter; PICO

PICO is an international collaboration consisting of scientists and engineers from Canada, the USA, Mexico, Spain, India, and the Czech Republic. Canada is a leader on this project which aims to search for Dark Matter using sophisticated Bubble Chambers located deep underground in the Canadian SNOLAB facility for astroparticle physics. Scientists have known for decades that nearly 85% of the matter in the Universe is in a form never directly observed on Earth. This matter is believed to be ubiquitous throughout the galaxy, but has interactions with normal matter so rarely that it has never been observed to date.Bubble Chambers contain a fluid in a metastable superheated state that may begin to boil when the tiniest amount of energy is deposited within the chamber. If a dark matter particle scatters within the sensitive volume, the recoiling nucleus will trigger a phase transition that is readily observable. PICO observes the initial bubble formation with an array of fast cameras, and as the nucleation is accompanied by a small burst of sound, sensitive piezo electric sensors surround the detector. The bane of all dark matter detectors is the presence of signals produced by natural radioactivity that can mimic the dark matter signal. PICO is unique in the world with its excellent background rejection capability for photons, electrons, alpha particles and neutrons, and the experiment is located deep underground to evade the cosmic rays that are prevalent at the surface of the Earth. PICO has the capability of discovering dark matter, or ruling out many of the theories describing its nature. PICO has already set world leading limits on the possible interaction strength, and with the funds provided through this grant, will be able to fully explore the region of parameter space many theories predict for dark matter. With the extended reach of the new detectors that will be operated with funds requested in this application, there is great optimism that a dark matter discovery may be near. The discovery of the nature of dark matter is one of the highest priorities in physics today. The dark matter is known to influence the formation of structures in the Universe and is an important factor in cosmological models. An understanding of dark matter and the way it interacts with normal matter will shape our theories of fundamental particle physics, astrophysics, and cosmology.

皮科是一个由来自加拿大、美国、墨西哥、西班牙、印度和捷克共和国的科学家和工程师组成的国际合作组织。加拿大是该项目的领导者，该项目旨在利用位于加拿大SNOLAB天体粒子物理设施地下深处的先进气泡室寻找暗物质。几十年来，科学家们已经知道，宇宙中近85%的物质是以一种从未在地球上直接观察到的形式存在的。这种物质被认为在整个银河系中无处不在，但与正常物质的相互作用非常罕见，以至于迄今为止从未被观察到。气泡室包含亚稳态过热状态的流体，当最少量的能量沉积在室内时，可能开始沸腾。如果一个暗物质粒子在敏感体积内散射，反冲的原子核将触发一个很容易观察到的相变。皮科通过一系列快速摄像头观察最初的气泡形成，当成核伴随着一小股声音时，敏感的压电传感器环绕在检测器周围。所有暗物质探测器的祸根是存在的信号产生的自然放射性，可以模仿暗物质的信号。皮科在世界上是独一无二的，它对光子、电子、α粒子和中子具有出色的背景抑制能力，实验位于地下深处，以躲避地球表面普遍存在的宇宙射线。 皮科有能力发现暗物质，或排除许多描述其性质的理论。皮科已经对可能的相互作用强度设定了世界领先的限制，并且通过这笔赠款提供的资金，将能够充分探索许多理论预测的暗物质参数空间区域。随着新探测器的延伸，将与本申请中要求的资金一起运行，人们非常乐观地认为暗物质的发现可能即将到来。 发现暗物质的本质是当今物理学的最高优先事项之一。已知暗物质会影响宇宙结构的形成，是宇宙学模型中的一个重要因素。对暗物质及其与正常物质相互作用方式的理解将塑造我们的基本粒子物理学，天体物理学和宇宙学理论。