Measurement of the time dependence of [formula omitted] mixing using a jet charge technique

• Published in: Physics letters. B 1994-05, Vol.327 (3), p.411-424
• Main Authors: Akers, R., Batley, J.R., Beaudoin, G., Beck, G.A., Behnke, T., Bentkowski, P., Bloodworth, I.J., Boutemeur, M., Bright-Thomas, P., Burgard, C., Capiluppi, P., Carnegie, R.K., Chu, S.L., Clayton, J.C., Dallapiccola, C., del Pozo, L.A., Deng, H., Duboscq, J.E., Fabbri, F., Folman, R., Foucher, M., Fukui, H., Geich-Gimbel, C., Gentit, F.X., Gillies, J.D., Gorn, W., Hattersley, P.M., Hauschild, M., Hawkes, C.M., Heflin, E., Hillier, S.J., Homer, R.J., Hughes-Jones, R.E., Igo-Kemenes, P., Jimack, M., Jones, R.W.L., Kawagoe, K., Kawamoto, T., Koetke, D.S., Kroll, J., Lauber, J., Leblanc, P., Le Du, P., Lellouch, D., Levinson, L., Li, Z., Loebinger, F.K., Long, G.D., Lorazo, B., Luig, A., Marcellini, S., Meijers, F., Mes, H., Mildenberger, J., Miller, D.J., Müller, U., Nguyen, H.H., O'Neale, S.W., Odorici, F., Ogren, H.O., Oram, C.J., Orito, S., Pfister, P., Pinfold, J., Pitman, D., Pritchard, T.W., Przysiezniak, H., Redmond, M.W., Richards, G.E., Rison, M., Robins, S.A., Sasaki, M., Schaile, A.D., Scharf, F., von der Schmitt, H., Schröder, M., Schütz, P., Schulz, M., Schwiening, J., Settles, M., Skillman, A., Snow, G.A., Stahl, A., Strom, D., Tarem, S., Tecchio, M., Tesch, N., Turner, M.F., VanDalen, G.J., Wagner, D.L., Ward, D.R., Ward, J.J., Watkins, P.M., Watson, A.T., Wilson, J.A., Wotton, S., Wyatt, T.R., Yaari, R., Yekutieli, G., Zeuner, W.
• Format: Article
• Language: English
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/0370-2693(94)90747-1

The observation and measurement of the time-dependence of B 0 d ↔ B 0 d mixing are described. The B 0 d meson is reconstructed in final states that contain a D ∗− and an ℓ +, where the b flavour of the B 0 d at decay time is tagged by the electric charge of the lepton. A new and efficient method, using a jet charge technique, is developed for identifying the b flavour of the produced B 0 d. From a sample of 556 D ∗±ℓ ∓ candidates reconstructed in the OPAL data collected during 1990–1993, the B 0 d ↔ B 0 d oscillation frequency is measured to be Δm d = 0.508 ± 0.075 (stat) ±0.025(syst) ps −1 giving an oscillation parameter of χ d = 0.73 ± 0.11 (stat) ±0.08 (syst), where 0.076 of the systematic error on χ d arises from the uncertainty on the B 0 d lifetime.