Search for dark matter with a 231-day exposure of liquid argon using DEAP-3600 at SNOLAB
Search for dark matter with a 231-day exposure of liquid argon using DEAP-3600 at SNOLAB
复制标题
DOI：
10.1103/physrevd.100.022004
复制
发表时间：
2019-07-24
影响因子：
5
通讯作者：
Zuniga-Reyes, A.
中科院分区：
文献类型：
--
作者：
Ajaj, R.;Amaudruz, P. -A.;Zuniga-Reyes, A.
DEAP-3600是一个单相液氩（LAr）直接探测暗物质实验，在SNOLAB（Sudbury，加拿大）地下2公里处运行。该探测器由3279公斤的LAr包含在一个球形丙烯酸容器。本文报告了对一个758吨的分析。在运行的第一年期间，在231个生存日期间进行了10天的暴露。在WIMP搜索区域没有观察到候选信号事件，这导致在LAr靶上WIMP-核子自旋无关截面的主要限制为3.9 x 10（-45）cm（2）（1.5 x 10（-44）cm（2）），对于100 GeV/c（2）（1 TeV/c（2））WIMP质量，在90% C. L。除了一个详细的背景模型，该分析演示了最好的脉冲形状歧视在LAr阈值，采用贝叶斯光电计数技术，以提高能量分辨率和歧视效率，并利用两个位置重建算法的基础上观察到的电荷和光子检测时间分布在每个光电倍增管。
DEAP-3600 is a single-phase liquid argon (LAr) direct-detection dark matter experiment, operating 2 km underground at SNOLAB (Sudbury, Canada). The detector consists of 3279 kg of LAr contained in a spherical acrylic vessel. This paper reports on the analysis of a 758 tonne . day exposure taken over a period of 231 live-days during the first year of operation. No candidate signal events are observed in the WIMP-search region of interest, which results in the leading limit on the WIMP-nucleon spin-independent cross section on a LAr target of 3.9 x 10(-45) cm(2) (1.5 x 10(-44) cm(2)) for a 100 GeV/c(2) (1 TeV/c(2)) WIMP mass at 90% C.L. In addition to a detailed background model, this analysis demonstrates the best pulse-shape discrimination in LAr at threshold, employs a Bayesian photoelectron-counting technique to improve the energy resolution and discrimination efficiency, and utilizes two position reconstruction algorithms based on the charge and photon detection time distributions observed in each photomultiplier tube.