近日，美国德克萨斯大学奥斯汀分校的Taewook Youn团队与美国加州大学圣克鲁斯分校的Matthew Gignac以及克罗地亚鲁杰尔·博什科维奇研究所的Rakhi Mahbubani合作，提出了针对短寿命的像素轨迹片段（tracklet）搜索优化方法。相关成果已于2023年3月7日在国际学术期刊《高能物理杂志》上发表。

该研究团队评估了一种针对短寿命进行轨迹片段搜索优化方法的性能，要求仅使用三个像素点重建轨迹片段，并要求伴随一个软轨迹以抑制背景噪声。他们估计使用这种优化搜索可以将现有搜索的灵敏度推广到参数空间的更大范围内。

据了解，像素轨迹片段是一种有前途的技术，即仅通过一个像素点重建的消失轨迹，用于在LHC分析中寻找属于近简并电弱多重态的暗物质候选粒子。然而，伪狄拉克电弱双态费米子可能是最有趣的候选粒子之一，它的寿命更短，因此现有的轨迹搜索在这种情况下的灵敏度较低。

附：英文原文

Title: Optimizing pixel tracklet searches for shorter lifetimes

Author: Gignac, Matthew, Kilic, Can, Mahbubani, Rakhi, Youn, Taewook

Issue&Volume: 2023-03-07

Abstract: Pixel tracklets, disappearing tracks reconstructed with only pixel hits, have proven to be a promising technique in LHC analyses to search for dark matter candidates at the LHC that belong to a nearly-degenerate electroweak multiplet. However, a Pseudo-Dirac electroweak doublet fermion, arguably the most interesting such possibility, has a shorter lifetime and therefore existing tracklet searches are less sensitive in this case. We assess the performance of a tracklet search optimized for shorter lifetimes by requiring only three pixel hits for the tracklet reconstruction, and by demanding an accompanying soft track for suppressing backgrounds. We estimate how far the sensitivity of existing searches can be extended into the region of parameter space with this optimized search.

DOI: 10.1007/JHEP03(2023)040

Source: https://link.springer.com/article/10.1007/JHEP03(2023)040