학술논문
Improving topological cluster reconstruction using calorimeter cell timing in ATLAS
Document Type
article
Author
Zwalinski, L; Zou, W; Zormpa, O; Zorbas, TG; Zoch, K; Zoccoli, A; Živković, L; Ziolkowski, M; Zinsser, J; Zimine, NI; Zhulanov, V; Zhukov, K; Zhuang, X; Zhu, Y; Zhu, J; Zhu, CG; Zhou, Y; Zhou, N; Zhou, H; Zhou, B; Zhong, D; Zheng, Z; Zheng, X; Zheng, K; Zheng, J; Zhemchugov, A; Zhao, Z; Zhao, Y; Zhao, T; Zhao, H; Zhang, Z; Zhang, Y; Zhang, X; Zhang, T; Zhang, S; Zhang, R; Zhang, P; Zhang, L; Zhang, K; Zhang, J; Zhang, DF; Zhang, B; Zhai, M; Zerwas, D; Zerradi, S; Zenz, S; Ženiš, T; Zenin, O; Zenger, DT; Zeng, JC; Zeng, H; Zeitnitz, C; Zaplatilek, O; Zanzi, D; Zang, J; Saa, JAZ; Zambito, S; Zakharchuk, N; Zakareishvili, T; Zak, ZK; Zaid, E; Zabinski, B; Zaazoua, M; Yue, L; Yuan, R; Yuan, M; Yu, Y; Yu, C; Young, C; Young, CJS; Younas, S; Yorita, K; Yin, P; Yexley, MR; Yeo, BK; Yeletskikh, I; Yeh, Y; Ye, X; Ye, S; Ye, J; Ye, H; Yap, YC; Yao, WM; Yang, Z; Yang, Y; Yang, X; Yang, T; Yang, S; Yang, HT; Yang, HJ
Source
European Physical Journal C. 84(5)
Subject
Language
Abstract
Clusters of topologically connected calorimeter cells around cells with large absolute signal-to-noise ratio (topo-clusters) are the basis for calorimeter signal reconstruction in the ATLAS experiment. Topological cell clustering has proven performant in LHC Runs 1 and 2. It is, however, susceptible to out-of-time pile-up of signals from soft collisions outside the 25 ns proton-bunch-crossing window associated with the event’s hard collision. To reduce this effect, a calorimeter-cell timing criterion was added to the signal-to-noise ratio requirement in the clustering algorithm. Multiple versions of this criterion were tested by reconstructing hadronic signals in simulated events and Run 2 ATLAS data. The preferred version is found to reduce the out-of-time pile-up jet multiplicity by ∼50% for jet pT∼20 GeV and by ∼80% for jet pT≳50 GeV, while not disrupting the reconstruction of hadronic signals of interest, and improving the jet energy resolution by up to 5% for 20