Dark matter search results from the complete exposure of the PICO-60 C3F8 bubble chamber
Dark matter search results from the complete exposure of the PICO-60 C3F8 bubble chamber
复制标题
DOI：
10.1103/physrevd.100.022001
复制
发表时间：
2019-07-09
影响因子：
5
通讯作者：
Zhang, J.
中科院分区：
文献类型：
--
作者：
Amole, C.;Ardid, M.;Zhang, J.
报告了Pico-60 C3F8暗物质探测器的最终结果，该探测器是一个气泡室，里面装满了52公斤的C3F8，位于SNOLAB地下实验室。该燃烧室在低至1.2keV的热力学阈值下运行，没有失去稳定性。获得了阈值为2.45keV的新的1404公斤/天的盲照射值，与先前的1167公斤/天的3.3keV/天的预期本底照射率大致相同。这种增加的曝光在一定程度上是由于一种新的光学跟踪分析，以更好地识别探测器壁附近的事件，从而允许更大的基准体积。对于25GeV的WIMP，这些结果将迄今为止最严格的直接探测约束设置在3.2×10(-41)cm(2)的弱相互作用大质量粒子(WIMP)-质子自旋相关截面上，比以前3-5GeV WIMP的Pico结果改进了一个数量级。
Final results are reported from operation of the PICO-60 C3F8 dark matter detector, a bubble chamber filled with 52 kg of C3F8 located in the SNOLAB underground laboratory. The chamber was operated at thermodynamic thresholds as low as 1.2 keV without loss of stability. A new blind 1404-kg-day exposure at 2.45 keV threshold was acquired with approximately the same expected total background rate as the previous 1167-kg-day exposure at 3.3 keV. This increased exposure is enabled in part by a new optical tracking analysis to better identify events near detector walls, permitting a larger fiducial volume. These results set the most stringent direct-detection constraint to date on the weakly interacting massive particle (WIMP)-proton spin-dependent cross section at 3.2 x 10(-41) cm(2) for a 25 GeV WIMP, improving on previous PICO results for 3-5 GeV WIMPs by an order of magnitude.