Aguilar-Arevalo A A, Alves D S M, Biedron S, Boissevain J, Borrego M, Chavez-Estrada M, Chavez A, Conrad J M, Cooper R L, Diaz A, Distel J R, D'Olivo J C, Dunton E, Dutta B, Elliott A, Evans D, Fields D, Greenwood J, Gold M, Gordon J, Guarincerri E, Huang E C, Kamp N, Kelsey C, Knickerbocker K, Lake R, Louis W C, Mahapatra R, Maludze S, Mirabal J, Moreno R, Neog H, deNiverville P, Pandey V, Plata-Salas J, Poulson D, Ray H, Renner E, Schaub T J, Shaevitz M H, Smith D, Sondheim W, Szelc A M, Taylor C, Thompson W H, Thornton R T, Tripathi M, Van Berg R, Van de Water R G, Verma S, Walker K
Universidad Nacional Autónoma de México, CDMX 04510, México.
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Phys Rev Lett. 2022 Jul 8;129(2):021801. doi: 10.1103/PhysRevLett.129.021801.
We report the first results of a search for leptophobic dark matter (DM) from the Coherent-CAPTAIN-Mills (CCM) liquid argon (LAr) detector. An engineering run with 120 photomultiplier tubes (PMTs) and 17.9×10^{20} protons on target (POT) was performed in fall 2019 to study the characteristics of the CCM detector. The operation of this 10-ton detector was strictly light based with a threshold of 50 keV and used coherent elastic scattering off argon nuclei to detect DM. Despite only 1.5 months of accumulated luminosity, contaminated LAr, and nonoptimized shielding, CCM's first engineering run has already achieved sensitivity to previously unexplored parameter space of light dark matter models with a baryonic vector portal. With an expected background of 115 005 events, we observe 115 005+16.5 events which is compatible with background expectations. For a benchmark mediator-to-DM mass ratio of m_{V_{B}}/m_{χ}=2.1, DM masses within the range 9 MeV≲m_{χ}≲50 MeV are excluded at 90% C. L. in the leptophobic model after applying the Feldman-Cousins test statistic. CCM's upgraded run with 200 PMTs, filtered LAr, improved shielding, and 10 times more POT will be able to exclude the remaining thermal relic density parameter space of this model, as well as probe new parameter space of other leptophobic DM models.
我们报告了从相干 - 船长 - 米尔斯（CCM）液态氩（LAr）探测器搜索轻子ophobic暗物质（DM）的首批结果。2019年秋季进行了一次工程运行，使用120个光电倍增管（PMT）和1.79×10²⁰个靶上质子（POT），以研究CCM探测器的特性。这个10吨重的探测器的运行严格基于光，阈值为50 keV，并利用与氩核的相干弹性散射来探测暗物质。尽管仅积累了1.5个月的光度，液态氩受到污染，且屏蔽未优化，但CCM的首次工程运行已经对具有重子矢量门户的轻暗物质模型中以前未探索的参数空间实现了灵敏度。预期背景事件数为115005次，我们观测到115005 + 16.5次事件，这与背景预期相符。对于基准中介子与暗物质质量比m_VB / m_χ = 2.1，在应用费尔德曼 - 考辛斯检验统计量后，在轻子ophobic模型中，9 MeV≲m_χ≲50 MeV范围内的暗物质质量在90%置信水平下被排除。CCM升级后的运行将使用200个PMT、经过过滤的液态氩、改进的屏蔽以及多10倍的POT，能够排除该模型剩余的热遗迹密度参数空间，并探测其他轻子ophobic暗物质模型的新参数空间。
