1级和2级CDF触发器可使用3级量热分辨率
Level-3 Calorimetric Resolution available for the Level-1 and Level-2 CDF Triggers
摘要：
随着Tevatron亮度的增加，需要复杂的选择来有效地在非常巨大的背景中选择稀有事件。为了解决这个问题，CDF已经将离线量热仪算法重建分辨率提升到2级，如果可能的话，甚至提升到1级，从而提高效率，同时保持速率可控。CDF运行II 2级热量计触发器在硬件中实现，并基于运行I中使用的简单算法。该系统在低光度下运行良好。随着Tevatron瞬时亮度的增加，由于这种简单算法的限制开始变得清晰：一些最重要的喷流和MET（丢失ET）相关的触发器在较高亮度的截面中具有较大的增长项。在本文中，我们提出了一个升级的2级热量计系统，使热量计触发塔的信息直接提供给CPU，允许更复杂的算法在软件中实现。2级喷射器和MET都可以几乎等同于离线质量，从而显著提高喷射器和MET相关触发器的性能和灵活性。然而，为了充分利用在级别1具有相同L2 MET分辨率的新L2触发能力，是必要的。新的1级MET分辨率由专用硬件计算。本文介绍了二级和一级量热计触发系统的设计、硬件和软件的实现及性能。
英文摘要：
As the Tevatron luminosity increases sophisticated selections are required to be efficient in selecting rare events among a very huge background. To cope with this problem, CDF has pushed the offline calorimeter algorithm reconstruction resolution up to Level 2 and, when possible, even up to Level 1, increasing efficiency and, at the same time, keeping under control the rates. The CDF Run II Level 2 calorimeter trigger is implemented in hardware and is based on a simple algorithm that was used in Run I. This system has worked well for Run II at low luminosity. As the Tevatron instantaneous luminosity increases, the limitation due to this simple algorithm starts to become clear: some of the most important jet and MET (Missing ET) related triggers have large growth terms in cross section at higher luminosity. In this paper, we present an upgrade of the Level 2 Calorimeter system which makes the calorimeter trigger tower information available directly to a CPU allowing more sophisticated algorithms to be implemented in software. Both Level 2 jets and MET can be made nearly equivalent to offline quality, thus significantly improving the performance and flexibility of the jet and MET related triggers. However in order to fully take advantage of the new L2 triggering capabilities having at Level 1 the same L2 MET resolution is necessary. The new Level-1 MET resolution is calculated by dedicated hardware. This paper describes the design, the hardware and software implementation and the performance of the upgraded calorimeter trigger system both at Level 2 and Level 1.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
