BUSKULIC, D (reprint author), CNRS, IN2P3, PHYS PARTICULES LAB, F-74019 ANNECY LE VIEUX, FRANCE.
In a sample of about 1.1 million hadronic Z decays recorded with the ALEPH detector during the 1990-1992 running of LEP, two unambiguous B(S) meson candidates were observed. From these events the mass of the B(S) meson has been measured to be 5.3686 +/- 0.0056 (stat.) +/- 0.0015 (syst.) GeV.