Automated workflows for critical time-dependent calibrations at the CMS experiment

G Cerminara,B Van Besien

doi:10.1088/1742-6596/664/7/072009

G Cerminara, B Van Besien

Open Access

https://doi.org/10.1088/1742-6596/664/7/072009

Copy DOI

Abstract

Fast and efficient methods for the calibration and the alignment of the detector are a key asset to exploit the physics potential of the Compact Muon Solenoid (CMS) detector and to ensure timely preparation of results for conferences and publications. To achieve this goal, the CMS experiment has set up a powerful framework. This includes automated workflows in the context of a prompt calibration concept, which allows for a quick turnaround of the calibration process following as fast as possible any change in running conditions. The presentation will review the design and operational experience of these workflows and the related monitoring system during the LHC Run I and focus on the development, deployment and commissioning in preparation of Run II.

Highlights

The Compact Muon Solenoid (CMS) is a multipurpose detector operated at the CERN Large Hadron Collider (LHC)
Within the superconducting solenoid volume are a silicon pixel and strip tracker, a lead tungstate crystal electromagnetic calorimeter (ECAL), and a brass and scintillator hadron calorimeter (HCAL), each composed of a barrel and two endcap sections
The optimal alignment and calibration of each detector component is a key requirement in order to achieve the full resolution and physics performance of the CMS detector

Summary

Introduction

The Compact Muon Solenoid (CMS) is a multipurpose detector operated at the CERN Large Hadron Collider (LHC). The express data belonging to the same run are processed by parallel jobs using the CMSSW reconstruction package [4] on the Tier0 computing farm These jobs perform both the reconstruction of the physics objects for analysis purposes and the selection of events for the alignment and calibration algorithms storing them in the AlCaReco datasets. Condition database and tools for automatic handling of the calibration constants The non-event data resulting from calibration and alignment algorithms, usually referred as conditions, are stored in the CMS Condition Database [3] for consumption by the online HLT selection and offline reconstruction of the physics objects This database relies on the Oracle technology for the persistency of the data and their retrieval according to their validity in time and their aggregation in consistent sets. Each point represents one luminosity section of 23 seconds0..00T2 he error bars reflect the statistical uncertainty from the fit [8]

Alignme-1nt of the large structures of the pixel barrel detector

Conclusions