826 research outputs found
Determination of ǀVcb☐from the semileptonic decay B0 → D*-l+ν
No full textSemileptonic decays B→ D*-l+νX were selected from a sample of 3.1 million hadronic Z decays collected by the DELPHI detector at LEP. A topological search for semileptonic B decays to resonant and non-resonant D*-π+ states was performed and the ratio of the branching fractions: Br(B → D*-l+νX)/Br(B → D*-+νX) + Br(B0 → + D*-l+ν) = 0.19 ± 0.10(stat) ± 0.06(syst) was determined. Taking into account this contribution, the differential decay width of B0 → D*-l+ν was measured as a function of the momentum transfer from the B to the D*- in two separate analyses, using exclusive and inclusive methods of D*- reconstruction. The distributions were fitted over the full momentum transfer range to extract the product of {pipe}Vcb{pipe} times the normalization of the decay form factor F(q2max): F(q2max){pipe}Vcb{pipe} = (35.4 ± 1.9(stat) ± 2.4(syst)) · 10-3. The value of {pipe}Vcb{pipe} was computed using theoretical calculations of F(q2max), giving: {pipe}Vcb{pipe} = (38.9 ± 2.0(stat) ± 2.6(syst) ± 1.7(theory)) · 10-3. The total branching fraction Br(B0 → D*-l+ν) was determined to be: Br(130, D*-l+v) = (5.52 ± 0.17(stat) ± 0.68(syst))%. © Springer-Verlag 1996
Determination of vertical bar V-cb vertical bar from the semileptonic decay B-0->D*(-)l(+)nu
No full textSemileptonic decays B --> D*(-)l(+)nu X were selected from a sample of 3.1 million hadronic Z decays collected by the DELPHI detector at LEP. A topological search for semileptonic B decays to resonant and non-resonant D*(-)pi(+) states was performed and the ratio of the branching fractions: Br(B --> D*(-)l(+)nu X)/Br(B --> D*(-)l(+)nu X) + Br(B-0 --> D*(-)l(+)nu) = 0.19 +/- 0.10(stat) +/- 0.06(syst) was determined. Taking into account this contribution, the differential decay width of B-0 --> D*(-)l(+)nu was measured as a function of the momentum transfer from the B to the D*(-) in two separate analyses, using exclusive and inclusive methods of D*(-) reconstruction. The distributions were fitted over the full momentum transfer range to extract the product of /V-cb/ times the normalization of the decay form factor F(q(max)(2)): F(q(max)(2))/V-cb/ = (35.4 +/- 1.9(stat) +/- 2.4(syst)) . 10(-3). The value of /V-cb/ was computed using theoretical calculations of F(q(max?2), giving: /V-cb/ = (38.9 +/- 2.0(stat) +/- 2.6(syst) +/- 1.7(theory)) . 10(-3). The total branching fraction Br(B-0 --> D*(-)l(-)nu) was determined to be: Br(B-0 --> D*(-)l(+)nu) = (5.52 +/- 0.17(stat) +/- 0.68(syst))%
A MEASUREMENT OF B+ AND B-0 LIFETIMES USING (D)OVER-BAR-L(+) EVENTS
No full textA measurement of B meson lifetimes is presented using data collected from 1991 to 1993 by the DELPHI detector at the LEP collider, Samples of events with a D meson and a lepton in the same jet are selected where () over bar D**l(+)v, the following B meson lifetimes and lifetime ratio are measured: tau(B+) = 1.61(-0.16)(+0.16) (stat.) +/- 0.12 (syst.) ps tau(B-0) = 1.61(-0.13)(+0.14) (stat.) +/- 0.08 (syst.) ps tau (B+)/tau(B-0) = 1.00(-0.15)(+0.17) (stat.) +/- 0.10 (syst.) and an average lifetime of B+ and B-0 mesons is obtained: tau(B) = 1.61(-0.07)(+0.08) (stat.) +/- 0.05 (syst.) p
PRODUCTION OF STRANGE B-BARYONS DECAYING INTO XI-/+-L-/+ PAIRS AT LEP
No full textAn excess of events containing, in a jet, a same-sign Xi(-/+) - l(-/+) pair as compared to those with an opposite-sign Xi(-/+) - l(-/+) pair has been observed in an analysis of 1.7 million hadronic Z(o) decays collected by the DELPHI detector at LEP between 1991 and 1993 inclusive. The probability for this signal to come from non B-baryon decays is less than 5 x 10(-4). The measured production fraction corresponds to: P(b --> B - baryon) x BR(B - baryon --> Xi(-) l(-) X) = (5.9 +/- 2.1 +/- 1.0) x 10(-4), per lepton species, averaged for electrons and muons and assuming the two channels have an equal contribution. Semileptonic decays of Lambda(b) baryons can account for less than 10% of these events and the major part of the signal has to originate from Xi(b) semileptonic decays, Using the subsample of these events where the Xi(-/+) trajectory has been measured in the Vertex Detector, the lifetime of B-baryons producing a Xi(-/+) in their semileptonic decay final state is found to be: tau(B - baryon --> Xi(-) l(-) X) = 1.5(-0.4)(+0.7) +/- 0.3 ps
Determination of |V(ub)| / |V(cb)| with DELPHI at LEP
No full textThe ratio of the CKM quark-mixing matrix elements \V-ub\/\V-cb\ has been measured using B hadron semileptonic decays. The analysis uses the reconstructed mass M-X of the secondary hadronic system produced in association with an identified lepton. Since B → X(u)l (v) over bar transitions are characterised by hadronic masses below those of the D mesons produced in B → X(c)l (v) over bar transitions, events with a reconstructed value of M-X significantly below the D mass are selected. Further signal enrichments are obtained using the topology of reconstructed decays and hadron identification. A fit to the numbers of decays in the b → u enriched and depleted samples with M-X above and below 1.6 GeV/c(2) and to the shapes of the lepton energy distribution in the B rest frame gives \V-ub\/\V-cb\ = 0.103 (+0.011)(-0.012) (stat.) +/- 0.016(syst.) +/- 0.010(model) and, correspondingly, a charmless semileptonic B decay branching fraction of BR(B → X(u)l (v) over bar)= (1.57 +/- 0.35 (stat.) +/- 0.48(syst.) +/- 0.27(model)) x 10(-3)
Erratum.Higgs boson searches in CP-conserving and CP-violating MSSM scenarios with the DELPHI detector
No full textErratum to: Eur. Phys. J. C 54, 1–35 (2008); doi:
10.1140/epjc/s10052-007-0506-1CICYT AEN99-0950 and AEN99-0761Abdallah, J., Abreu, P., Adam, W., Adzic, P., Albrecht, T., Alemany-Fernandez, R., Allmendinger, T., Allport, P.P., Amaldi, U., Amapane, N., Amato, S., Anashkin, E., Andreazza, A., Andringa, S., Anjos, N., Antilogus, P., Apel, W.-D., Arnoud, Y., Ask, S., Asman, B., Augustin, J.E., Augustinus, A., Baillon, P., Ballestrero, A., Bambade, P., Barbier, R., Bardin, D., Barker, G.J., Baroncelli, A., Battaglia, M., Baubillier, M., Becks, K.-H., Begalli, M., Behrmann, A., Ben-Haim, E., Benekos, N., Benvenuti, A., Berat, C., Berggren, M., Berntzon, L., Bertrand, D., Besancon, M., Besson, N., Bloch, D., Blom, M., Bluj, M., Bonesini, M., Boonekamp, M., Booth, P.S.L., Borisov, G., Botner, O., Bouquet, B., Bowcock, T.J.V., Boyko, I., Bracko, M., Brenner, R., Brodet, E., Bruckman, P., Brunet, J.M., Buschbeck, B., Buschmann, P., Calvi, M., Camporesi, T., Canale, V., Carena, F., Castro, N., Cavallo, F., Chapkin, M., Charpentier, Ph., Checchia, P., Chierici, R., Chliapnikov, P., Chudoba, J., Chung, S.U., Cieslik, K., Collins, P., Contri, R., Cosme, G., Cossutti, F., Costa, M.J., Crennell, D., Cuevas, J., D'Hondt, J., Dalmau, J., Da Silva, T., Da Silva, W., Della Ricca, G., De Angelis, A., De Boer, W., De Clercq, C., De Lotto, B., De Maria, N., De Min, A., De Paula, L., Di Ciaccio, L., Di Simone, A., Doroba, K., Drees, J., Eigen, G., Ekelof, T., Ellert, M., Elsing, M., Espirito Santo, M.C., Fanourakis, G., Fassouliotis, D., Feindt, M., Fernandez, J., Ferrer, A., Ferro, F., Flagmeyer, U., Foeth, H., Fokitis, E., Fulda-Quenzer, F., Fuster, J., Gandelman, M., Garcia, C., Gavillet, Ph., Gazis, E., Gokieli, R., Golob, B., Gomez-Ceballos, G., Goncalves, P., Graziani, E., Grosdidier, G., Grzelak, K., Guy, J., Haag, C., Hallgren, A., Hamacher, K., Hamilton, K., Haug, S., Hauler, F., Hedberg, V., Hennecke, M., Herr, H., Hoffman, J., Holmgren, S.-O., Holt, P.J., Houlden, M.A., Jackson, J.N., Jarlskog, G., Jarry, P., Jeans, D., Johansson, E.K., Johansson, P.D., Jonsson, P., Joram, C., Jungermann, L., Kapusta, F., Katsanevas, S., Katsoufis, E., Kernel, G., Kersevan, B.P., Kerzel, U., King, B.T., Kjaer, N.J., Kluit, P., Kokkinias, P., Kourkoumelis, C., Kouznetsov, O., Krumstein, Z., Kucharczyk, M., Lamsa, J., Leder, G., Ledroit, F., Leinonen, L., Leitner, R., Lemonne, J., Lepeltier, V., Lesiak, T., Liebig, W., Liko, D., Lipniacka, A., Lopes, J.H., Lopez, J.M., Loukas, D., Lutz, P., Lyons, L., MacNaughton, J., Malek, A., Maltezos, S., Mandl, F., Marco, J., Marco, R., Marechal, B., Margoni, M., Marin, J.-C., Mariotti, C., Markou, A., Martinez-Rivero, C., Masik, J., Mastroyiannopoulos, N., Matorras, F., Matteuzzi, C., Mazzucato, F., Mazzucato, M., Mc Nulty, R., Meroni, C., Migliore, E., Mitaroff, W., Mjoernmark, U., Moa, T., Moch, M., Moenig, K., Monge, R., Montenegro, J., Moraes, D., Moreno, S., Morettini, P., Mueller, U., Muenich, K., Mulders, M., Mundim, L., Murray, W., Muryn, B., Myatt, G., Myklebust, T., Nassiakou, M., Navarria, F., Nawrocki, K., Nicolaidou, R., Nikolenko, M., Oblakowska-Mucha, A., Obraztsov, V., Olshevski, A., Onofre, A., Orava, R., Osterberg, K., Ouraou, A., Oyanguren, A., Paganoni, M., Paiano, S., Palacios, J.P., Palka, H., Papadopoulou, Th.D., Pape, L., Parkes, C., Parodi, F., Parzefall, U., Passeri, A., Passon, O., Peralta, L., Perepelitsa, V., Perrotta, A., Petrolini, A., Piedra, J., Pieri, L., Pierre, F., Pimenta, M., Piotto, E., Podobnik, T., Poireau, V., Pol, M.E., Polok, G., Pozdniakov, V., Pukhaeva, N., Pullia, A., Rames, J., Read, A., Rebecchi, P., Rehn, J., Reid, D., Reinhardt, R., Renton, P., Richard, F., Ridky, J., Rivero, M., Rodriguez, D., Romero, A., Ronchese, P., Roudeau, P., Rovelli, T., Ruhlmann-Kleider, V., Ryabtchikov, D., Sadovsky, A., Salmi, L., Salt, J., Sander, C., Savoy-Navarro, A., Schwickerath, U., Sekulin, R., Siebel, M., Sisakian, A., Smadja, G., Smirnova, O., Sokolov, A., Sopczak, A., Sosnowski, R., Spassov, T., Stanitzki, M., Stocchi, A., Strauss, J., Stugu, B., Szczekowski, M., Szeptycka, M., Szumlak, T., Tabarelli, T., Taffard, A.C., Tegenfeldt, F., Timmermans, J., Tkatchev, L., Tobin, M., Todorovova, S., Tome, B., Tonazzo, A., Tortosa, P., Travnicek, P., Treille, D., Tristram, G., Trochimczuk, M., Troncon, C., Turluer, M.-L., Tyapkin, I.A., Tyapkin, P., Tzamarias, S., Uvarov, V., Valenti, G., Van Dam, P., Van Eldik, J., Van Remortel, N., Van Vulpen, I., Vegni, G., Veloso, F., Venus, W., Verdier, P., Verzi, V., Vilanova, D., Vitale, L., Vrba, V., Wahlen, H., Washbrook, A.J., Weiser, C., Wicke, D., Wickens, J., Wilkinson, G., Winter, M., Witek, M., Yushchenko, O., Zalewska, A., Zalewski, P., Zavrtanik, D., Zhuravlov, V., Zimin, N.I., Zintchenko, A., Zupan, M
Measurement of the mass and width of the W boson in e+e- collisions at s√= 161–209 GeV
No full textAbdallah, J., Abreu, P., Adam, W., Adzic, P., Albrecht, T., Alemany-Fernandez, R., Allmendinger, T., Allport, P.P., Amaldi, U., Amapane, N., Amato, S., Anashkin, E., Andreazza, A., Andringa, S., Anjos, N., Antilogus, P., Apel, W.-D., Arnoud, Y., Ask, S., Asman, B., Augustin, J.E., Augustinus, A., Baillon, P., Ballestrero, A., Bambade, P., Barbier, R., Bardin, D., Barker, G.J., Baroncelli, A., Battaglia, M., Baubillier, M., Becks, K.-H., Begalli, M., Behrmann, A., Ben-Haim, E., Benekos, N., Benvenuti, A., Berat, C., Berggren, M., Bertrand, D., Besancon, M., Besson, N., Bloch, D., Blom, M., Bluj, M., Bonesini, M., Boonekamp, M., Booth, P.S.L., Borisov, G., Botner, O., Bouquet, B., Bowcock, T.J.V., Boyko, I., Bracko, M., Brenner, R., Brodet, E., Bruckman, P., Brunet, J.M., Buschbeck, B., Buschmann, P., Calvi, M., Camporesi, T., Canale, V., Carena, F., Castro, N., Cavallo, F., Chapkin, M., Charpentier, Ph., Checchia, P., Chierici, R., Chliapnikov, P., Chudoba, J., Chung, S.U., Cieslik, K., Collins, P., Contri, R., Cosme, G., Cossutti, F., Costa, M.J., Crennell, D., Cuevas, J., D'Hondt, J., Da Silva, T., Da Silva, W., Della Ricca, G., De Angelis, A., De Boer, W., De Clercq, C., De Lotto, B., De Maria, N., De Min, A., De Paula, L., Di Ciaccio, L., Di Simone, A., Doroba, K., Drees, J., Duperrin, A., Eigen, G., Ekelof, T., Ellert, M., Elsing, M., Espirito Santo, M.C., Fanourakis, G., Fassouliotis, D., Feindt, M., Fernandez, J., Ferrer, A., Ferro, F., Flagmeyer, U., Foeth, H., Fokitis, E., Fulda-Quenzer, F., Fuster, J., Gandelman, M., Garcia, C., Gavillet, Ph., Gazis, E., Gokieli, R., Golob, B., Gomez-Ceballos, G., Goncalves, P., Graziani, E., Grosdidier, G., Grzelak, K., Guy, J., Haag, C., Hallgren, A., Hamacher, K., Hamilton, K., Haug, S., Hauler, F., Hedberg, V., Hennecke, M., Hoffman, J., Holmgren, S.-O., Holt, P.J., Houlden, M.A., Jackson, J.N., Jarlskog, G., Jarry, P., Jeans, D., Johansson, E.K., Jonsson, P., Joram, C., Jungermann, L., Kapusta, F., Katsanevas, S., Katsoufis, E., Kernel, G., Kersevan, B.P., Kerzel, U., King, B.T., Kjaer, N.J., Kluit, P., Kokkinias, P., Kourkoumelis, C., Kouznetsov, O., Krumstein, Z., Kucharczyk, M., Lamsa, J., Leder, G., Ledroit, F., Leinonen, L., Leitner, R., Lemonne, J., Lepeltier, V., Lesiak, T., Liebig, W., Liko, D., Lipniacka, A., Lopes, J.H., Lopez, J.M., Loukas, D., Lutz, P., Lyons, L., MacNaughton, J., Malek, A., Maltezos, S., Mandl, F., Marco, J., Marco, R., Marechal, B., Margoni, M., Marin, J.-C., Mariotti, C., Markou, A., Martinez-Rivero, C., Masik, J., Mastroyiannopoulos, N., Matorras, F., Matteuzzi, C., Mazzucato, F., Mazzucato, M., Mc Nulty, R., Meroni, C., Migliore, E., Mitaroff, W., Mjoernmark, U., Moa, T., Moch, M., Moenig, K., Monge, R., Montenegro, J., Moraes, D., Moreno, S., Morettini, P., Mueller, U., Muenich, K., Mulders, M., Mundim, L., Murray, W., Muryn, B., Myatt, G., Myklebust, T., Nassiakou, M., Navarria, F., Nawrocki, K., Nicolaidou, R., Nikolenko, M., Oblakowska-Mucha, A., Obraztsov, V., Olshevski, A., Onofre, A., Orava, R., Osterberg, K., Ouraou, A., Oyanguren, A., Paganoni, M., Paiano, S., Palacios, J.P., Palka, H., Papadopoulou, Th.D., Pape, L., Parkes, C., Parodi, F., Parzefall, U., Passeri, A., Passon, O., Peralta, L., Perepelitsa, V., Perrotta, A., Petrolini, A., Piedra, J., Pieri, L., Pierre, F., Pimenta, M., Piotto, E., Podobnik, T., Poireau, V., Pol, M.E., Polok, G., Pozdniakov, V., Pukhaeva, N., Pullia, A., Radojicic, D., Rames, J., Read, A., Rebecchi, P., Rehn, J., Reid, D., Reinhardt, R., Renton, P., Richard, F., Ridky, J., Rivero, M., Rodriguez, D., Romero, A., Ronchese, P., Roudeau, P., Rovelli, T., Ruhlmann-Kleider, V., Ryabtchikov, D., Sadovsky, A., Salmi, L., Salt, J., Sander, C., Savoy-Navarro, A., Schwickerath, U., Sekulin, R., Siebel, M., Simard, L., Sisakian, A., Smadja, G., Smirnova, O., Sokolov, A., Sopczak, A., Sosnowski, R., Spassov, T., Stanitzki, M., Stocchi, A., Strauss, J., Stugu, B., Szczekowski, M., Szeptycka, M., Szumlak, T., Tabarelli, T., Tegenfeldt, F., Thomas, J., Timmermans, J., Tkatchev, L., Tobin, M., Todorovova, S., Tome, B., Tonazzo, A., Tortosa, P., Travnicek, P., Treille, D., Tristram, G., Trochimczuk, M., Troncon, C., Turluer, M.-L., Tyapkin, I.A., Tyapkin, P., Tzamarias, S., Uvarov, V., Valenti, G., Van Dam, P., Van Eldik, J., Van Remortel, N., Van Vulpen, I., Vegni, G., Veloso, F., Venus, W., Verdier, P., Verzi, V., Vilanova, D., Vitale, L., Vrba, V., Wahlen, H., Washbrook, A.J., Weiser, C., Wicke, D., Wickens, J., Wilkinson, G., Winter, M., Witek, M., Yushchenko, O., Zalewska, A., Zalewski, P., Zavrtanik, D., Zhuravlov, V., Zimin, N.I., Zintchenko, A., Zupan, M
m(b) at M(Z)
No full textThe value of the quark mass at the scale defined in the renormalization scheme, , is determined using 2.8 million hadronic Z decays collected during 1992-1994 by the DELPHI detector to be, This analysis considers NLO corrections to the three-jet production rate including mass effects, and the result obtained agrees with the QCD prediction of having a running -quark mass at an energy scale equal to . This is the first time that such a measurement has been performed far above the productio
Multiplicity distributions of charged hadrons produced in (anti)neutrino-deuterium charged- and neutral-current interactions
No full textResults are presented on the multiplicity distributions of charged hadrons produced in νn, νp, {Mathematical expression} and {Mathematical expression} charged-current interactions for the hadronic energy range 2GeV≤W≤14GeV (corresponding approximately to the neutrino energy range 5GeV≤E v≤150GeV). The experimental distributions are analysed in terms of binomial distributions. With increasing hadronic energy we find a smooth transition from an ordinary binomial via Poissonian to the negative binomial function. KNO scaling holds approximately for the multiplicity distribution for the whole phase space. Data on the multiplicity distributions for neutral-current interactions are also presented. © 1989 Società Italiana di Fisica
Measurement of the (B)over-bar -> D-(*)pi l(nu)over-bar(l) branching fraction
No full textA study of b semileptonic decays into D, D pi(+/-) and D*pi(+/-) final states is presented. The D-0, D+ and D*(+) mesons are exclusively reconstructed in Z decay data recorded from 1992 to 1995 in the DELPHI experiment at LEP. The overall branching fractions are measured to be: BR(b –> D(0)l(-)<(upsilon)over bar>X-l) = (7.04 +/- 0.34(stat) +/- 0.36 (syst.exp) +/- 0.17(BRD))%, BR(b –> D(+)l(-)<(upsilon)over bar>X-l) = (2.72 +/- 0.19(stat) +/- 0.16(syst.exp) +/- 0.18(BRD))%, BR(b –> D*(+)l(-)<(upsilon)over bar>X-l) = (2.75 +/- 0.17(stat) +/- 0.13 (syst.exp) +/- 0.09 (BRD))%, where the D-0 and D+ results include also contributions from D*(0) and D*(+) decays. A fit to the distribution of the pi(+/-) impact parameter to the primary interaction vertex provides a measurement of the b semileptonic branching fractions into the D(0)pi(+/-)X, D(+)pi(+/-)X and D*(+)pi(+/-)X final states. Assuming that single pion decay modes of B mesons dominate, the partial rates for (B) over bar –> D pi l(-)<(upsilon)over bar>(l) and (B) over bar –> D*pi l(-)<(upsilon)over bar>(l) have been obtained, corresponding to a total branching fraction: BR((B) over bar –> D pi l(-)<(upsilon)over bar>(l)) + BR((B) over bar –> D*pi l(-)<(upsilon)over bar>(l)) = (3.40 +/- 0.52 (stat) +/- 0.32 (syst))%. This result agrees well with the observed difference between the total B semileptonic branching fraction and the sum of the (B) over bar –> Dl(-) upsilon(l) and D* l(-)<(upsilon)over bar>(l) branching fractions. (C) 2000 Elsevier Science B.V. All rights reserved
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