Key4hep, a framework for future HEP experiments and its use in FCC

Abstract

The road map to the FCC Feasibility Study Report, for submission to the next Update of the European Strategy for Particle Physics, will require detailed simulation and advanced reconstruction algorithms to explore and maximise the physics reach of proposed detector solutions. The optimisation process will require maximal flexibility in changing detector geometries, materials and sensitive areas, and efficient tools to quantify the overall performance. To synergise such developments the CEPC, CLIC, FCC, ILC and SCT communities have engaged in the commissioning of a 'Turnkey Software Stack' (Key4hep), which would provide all the necessary ingredients, from simulation to analysis, for future experiments. This approach is based on the positive experience of the linear collider projects ILC and CLIC, which have developed and used a common software stack (iLCSoft) over the last decade. Key4hep aims to cover most, if not all, future linear and circular machines colliding leptons (electrons, muons), and hadrons. The common software ecosystem will facilitate writing specific components for experiments ensuring coherency and maximising the re-use of established solutions. Project-specific software frameworks will require adaptation to fully profit from the common software base. In this essay we present the status and plans for re-framing the FCC software framework, FCCSW, around Key4hep and discuss the challenges associated with the transition.

Status and Perspectives for FCC-ee Detector Background Studies

“…A complete modeling of the elements and materials present in the Machine-Detector Interface region is required to correctly assess the background particles which arrive to the detector, including the production of secondary showers and backscattered particles. For the studies presented in this work, the detectors and MDI elements are modeled in the Key4hep framework [2], which is the tool used for particle tracking.…”

The Future Circular Collider: a Summary for the US 2021 Snowmass Process

“…The online, offline, and software requirements [250,251,252] for the FCC-ee are dominated by those of the Z pole running with a physics event rate of ∼ 200 kHz. However, the data throughput rate, storage and CPU resource needs will be similar to those of the HL-LHC, in operation long before the FCC-ee.…”

“…For what relates to software requirements, also in this case the developments and solutions that will be done and put in place for the HL-LHC will be very beneficial to the FCCee. FCC is currently fully committed in implementing its software around Key4hep [252], a software ecosystem which aims to become the common "Turnkey Software Stack" for future experiments. Key4hep is being actively developed and is expected to cover most, if not all, the needs of future colliders.…”

Offline Data Processing Software for the Super Tau Charm Facility

“…The overall architecture of OSCAR is shown in Figure 1. The OSCAR system is composed of three layers: the bottom layer includes some commonly used libraries and interfaces to the frequently used software and tools in the HEP community, such as ROOT [4], Geant4 [5], as well as some of the Common Turnkey Software Stack (Key4hep) [6], such as podio [7] and DD4hep [8]. The core software layer includes the underlying framework, and other common components used in offline data processing, such as the event data model (EDM), event data and detector data management systems, providing key and common functionalities for the offline software.…”