Computing models in high energy physics

Abstract

High Energy Physics Experiments (HEP experiments in the following) have been at least in the last 3 decades at the forefront of technology, in aspects like detector design and construction, number of collaborators, and complexity of data analyses. As uncommon in previous particle physics experiments, the computing and data handling aspects have not been marginal in their design and operations; the cost of the IT related components, from software development to storage systems and to distributed complex e-Infrastructures, has raised to a level which needs proper understanding and planning from the first moments in the lifetime of an experiment. In the following sections we will first try to explore the computing and software solutions developed and operated in the most relevant past and present experiments, with a focus on the technologies deployed; a technology tracking section is presented in order to pave the way to possible solutions for next decade experiments, and beyond. While the focus of this review is on offline computing model, the distinction is a shady one, and some experiments have already experienced contaminations between triggers selection and offline workflows; it is anticipated the trend will continue in the future.