Commissioning of the ALICE Muon Spectrometer Trigger at LHC

S. Ahn , R. Arnaldi , Y.W. Baek , A. Baldit (1) , V. Barret (1) , N. Bastid (1) , Guillaume Batigne (2) , J.L. Beney (2) , R. Berny (2) , L. Bianchi , A. Blanc (1) , G. Blanchard (1) , F. Boss , E. Chiavassa , P. Cortese , P. Crochet (1) , G. Dellacasa , Marcon. De , P. Dupieux (1) , A. Ferretti , M. Gagliardi , M. Gallio , C. Insa (1) , X. Lopez (1) , G. Luparello , Loïc Manceau (1) , F. Manso (1) , P. Mereu , A. Musso , C. Oppedisano , A. Picotti , C. Renard (2) , P. Rosnet (1) , Daniel Roy (2) , L. Royer (1) , P. Saturnini (1) , E. Scomparin , Diego Stocco (2) , E. Vercellin , B. Vulpescu (1) , X. Zhang (1)

1 LPC - Laboratoire de Physique Corpusculaire - Clermont-Ferrand
2 SUBATECH - Laboratoire SUBATECH Nantes

ALICE (a large ion collider experiment) is the LHC experiment dedicated to the study of ultra-relativistic heavy ion collisions. The ALICE muon spectrometer covers a large range in pseudo-rapidity and is designed to study quarkonia and heavy flavours decaying into (di-)muons. The high particle multiplicities environment in such collisions require a specific, fast and efficient trigger system, the muon trigger. It consists of four planes of RPC detectors, covering an area of 36 m2 each, 21k front-end channels and a fast-decision electronics. The muon trigger is designed to reconstruct (muon) tracks and deliver a trigger signal each 25 ns (40 MHz) with a total latency of 800 ns. The hit position on the RPC is measured in two orthogonal directions with an accuracy of about 1 cm. The performance measured with the first p–p collisions at sqrt (s)= 900 GeV carried out in December 2009 is reported.

Mots clés: Resistive plate chamber; Trigger system; Spectrometer; Muons; ALICE; LHC

Domaines: Physique des Hautes Energies - Expérience [hep-ex]

S. Ahn, R. Arnaldi, Y.W. Baek, A. Baldit, V. Barret, et al.. Commissioning of the ALICE Muon Spectrometer Trigger at LHC. X Workshop on Resistive Plate Chambers and Related Detectors, Feb 2010, Darmstadt, Germany. 4p., ⟨10.1016/j.nima.2010.08.123⟩. ⟨in2p3-00531413⟩