The resolution and the linearity of time measurements made with the CMS electromagnetic calorimeter are studied with samples of data from test beam electrons, cosmic rays, and beam-produced muons. The resulting time resolution measured by lead tungstate crystals is better than 100 ps for energy deposits larger than 10 GeV. Crystal-to-crystal synchronization with a precision of 500 ps is performed using muons produced with the first LHC beams in 2008.

Time reconstruction and performance of the CMS electromagnetic calorimeter

BELLAN, PAOLO;BISELLO, DARIO;BORSATO, ENRICO;BRANCA, ANTONIO;CARLIN, ROBERTO;DE MATTIA, MARCO;GASPARINI, FABRIZIO;GASPARINI, UGO;GIUBILATO, PIERO;MARGONI, MARTINO;MATTIAZZO, SERENA;MENEGUZZO, ANNA TERESA;NESPOLO, MASSIMO;PERROZZI, LUCA;POZZOBON, NICOLA;RONCHESE, PAOLO;SIMONETTO, FRANCO;TOSI, MIA;A. Triossi;VANINI, SARA;ZOTTO, PIERLUIGI;ZUMERLE, GIANNI;ROSSIN, ROBERTO;