Determining the bubble nucleation efficiency of low-energy nuclear recoils in superheated C3F8 dark matter detectors
Determining the bubble nucleation efficiency of low-energy nuclear recoils in superheated C3F8 dark matter detectors
复制标题
确定过热 C3F8 暗物质探测器中低能核反冲的气泡成核效率
DOI：
10.1103/physrevd.106.122003
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发表时间：
2022
影响因子：
5
通讯作者：
Cripe, C.
中科院分区：
文献类型：
--
作者：
Ali, B.;Arnquist, I. J.;Baxter, D.;Behnke, E.;Bressler, M.;Broerman, B.;Clark, K.;Collar, J. I.;Cooper, P. S.;Cripe, C.
过热液体中低能核反冲的气泡成核效率对于解释直接寻找弱相互作用大质量粒子(WIMP)暗物质的结果起着关键作用。Pico的合作展示了在从2.1到3.9keV的不同热力学阈值下使用五个不同的中子谱获取的校准数据的过热碳和氟反冲对气泡成核的效率的结果。为了使模型引入的不确定性最小，提出了一个包含系统误差作为干扰参数的广义分段线性模型，而不是假定核反冲效率的任何特定函数形式。用马尔可夫链蒙特卡罗程序同时采样了2.45和3.29keV热力学阈值下的氟和碳的核反冲效率。当热力学Seitz阈值为2.45KEV(3.29KEV)时，氟的成核效率为3.3KEV(3.7KEV)，对于碳，在2.45KEV(3.29KEV)的阈值下，成核效率为10.6KEV(11.1KEV)。模拟数据集用于计算拟合的p值，以确认所使用的模型与数据兼容。Fit范式还评估了潜在的系统性偏差，这些偏差虽然很小，但已经得到了纠正。执行其他步骤以计算Pico-60探测器中WIMP的预期相互作用率，这是计算WIMP排除限度的要求。
The bubble nucleation efficiency of low-energy nuclear recoils in superheated liquids plays a crucial role in interpreting results from direct searches for weakly interacting massive particle (WIMP) dark matter. The PICO collaboration presents the results of the efficiencies for bubble nucleation from carbon and fluorine recoils in superheatedfrom calibration data taken with five distinct neutron spectra at various thermodynamic thresholds ranging from 2.1 to 3.9 keV. Instead of assuming any particular functional forms for the nuclear recoil efficiency, a generalized piecewise linear model is proposed with systematic errors included as nuisance parameters to minimize model-introduced uncertainties. A Markov chain Monte Carlo routine is applied to sample the nuclear recoil efficiency for fluorine and carbon at 2.45 and 3.29 keV thermodynamic thresholds simultaneously. The nucleation efficiency for fluorine was found to befor nuclear recoils of 3.3 keV (3.7 keV) at a thermodynamic Seitz threshold of 2.45 keV (3.29 keV), and for carbon the efficiency was found to befor recoils of 10.6 keV (11.1 keV) at a threshold of 2.45 keV (3.29 keV). Simulated datasets are used to calculate a p value for the fit, confirming that the model used is compatible with the data. The fit paradigm is also assessed for potential systematic biases, which although small, are corrected for. Additional steps are performed to calculate the expected interaction rates of WIMPs in the PICO-60 detector, a requirement for calculating WIMP exclusion limits.