The TIER-2 site for the ARGO-YBJ experiment

The ARGO-YBJ experiment is taking data at the Yangbajing International Cosmic Ray Observatory located at an altitude of about 4300 m a.s.l. (Tibet, P.R. China). The detector consists of an EAS array made of a full coverage RPCs carpet. The experiment is taking data since 2007 in the final configuration, the trigger rate is about 3.5 kHz producing a throughput of data of about 2.5 MB/s. Taking into account the high duty cycle of the experiment, the amount of raw data collected is about 200 TB/year and the amount of reconstructed data is about 60 TB/year. The management of this volume of data and the production of a huge amount of Monte Carlo data samples require a suitable computing power. A TIER-2 site is arranged to face out these tasks. In this paper the structure of the data transfer method and data reconstruction/analysis based on the TIERs are presented. The hardware infrastructure and software architecture of the Roma 3 TIER-2 site of the ARGO-YBJ experiment are also discussed.