Published: 2003
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We present a measurement of the total width[Lambda][sub tot][sup[eta][sub c]] and mass M[sub[eta][sub c]] of the[eta][sub c] meson with the BABAR detector at the PEP-II B-factory at SLAC. The results based on a data sample of 88 fb[sub -1] are[Lambda][sub tot][sup[eta][sub c]]= (33.3[+-] 2.5(stat.)[+-] 0.8(sys.))MeV/c[sup 2] and M[sub[eta][sub c]]= (2983.3[+-] 1.2[+-] 1.8) MeV/c[sup 2]. An enhancement observed around 3.63 GeV/c[sup 2] can be interpreted as an evidence for the[eta][sub c](2S) state. In addition a preliminary measurement of the[tau] lepton lifetime using 30.2 fb[sup -1] is described. The measured[tau] lifetime is:[tau][sub[tau]]= (290.8[+-] 1.5(stat.)[+-] 1.6(syst.)) fs.