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Comparison of inclusive fractional momentum distributions of quark and gluon jets produced in e+e- annihilation

Zeitschrift für Physik C Particles and Fields 45:1 (1989) 1-10

Authors:

W Braunschweig, R Gerhards, FJ Kirschfink, HU Martyn, B Bock, HM Fischer, H Hartmann, J Hartmann, E Hilger, A Jocksch, R Wedemeyer, B Foster, AJ Martin, E Bernardi, J Chwastowski, A Eskreys, K Gather, K Genser, H Hulschig, P Joos, H Kowalski, A Ladage, B Löhr, D Lüke, P Mättig, D Notz, JM Pawlak, KU Pösnecker, E Ros, D Trines, R Walczak, G Wolf, H Kolanoski, T Kracht, J Krüger, E Lohrmann, G Poelz, W Zeuner, J Hassard, J Shulman, D Su, IR Tomalin, F Barreiro, A Leites, J del Peso, MG Bowler, PN Burrows, RJ Cashmore, GP Heath, ME Veitch, JC Hart, DH Saxon, S Brandt, M Holder, Y Eisenberg, U Karshon, G Mikenberg, A Montag, D Revel, E Ronat, A Shapira, N Wainer, G Yekutieli, D Muller, S Ritz, D Strom, M Takashima, SL Wu, G Zobernig

Abstract:

Inclusive charged particle production in e+e- annihilation into hadrons is studied in terms of the particle fractional momentum xp. The xp distribution for gluon jets is extracted by comparing two data samples measured in the TASSO detector: nearly symmetric three jet events at centre-of-mass energy W∼35 GeV and two jet events at W∼22 GeV, yielding quark and gluon jets of similar energies (∼11.5 GeV). No significant difference is observed between quark and gluon jets. Monte Carlo models based on parton showers describe the trend and energy variation of the data better than a model with second order matrix element in αs. © 1989 Springer-Verlag.
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Measurement of the average lifetime of B hadrons

Zeitschrift für Physik C Particles and Fields 44:1 (1989) 1-13

Authors:

W Braunschweig, R Gerhards, FJ Kirschfink, HU Martyn, B Bock, HM Fischer, H Hartmann, J Hartmann, E Hilger, A Jocksch, R Wedemeyer, B Foster, AJ Martin, AJ Sephton, F Barreiro, E Bernardi, J Chwastowski, A Eskreys, K Gather, K Genser, H Hultschig, P Joos, H Kowalski, A Ladage, B Löhr, D Lüke, P Mättig, D Notz, JM Pawlak, KU Pösnecker, E Ros, D Trines, R Walczak, G Wolf, H Kolanoski, T Kracht, J Krüger, E Lohrmann, G Poelz, W Zeuner, A Belk, DM Binnie, J Hassard, J Shulman, D Su, A Leites, J del Peso, C Balkwill, MG Bowler, PN Burrows, RJ Cashmore, GP Heath, PN Ratoff, IM Silvester, IR Tomalin, ME Veitch, GE Forden, JC Hart, DH Saxon, S Brandt, M Holder, L Labarga, Y Eisenberg, U Karshon, G Mikenberg, A Montag, D Revel, E Ronat, A Shapira, N Wainer, G Yekutieli, A Caldwell, D Muller, S Ritz, D Strom, M Takashima, SL Wu, G Zobernig

Abstract:

The average lifetime of B hadrons has been measured by the TASSO collaboration using 110 pb-1 of data collected in 1986 at a center of mass energy of 35 GeV. Measurements by three different methods are presented and a method of B-enrichment is discussed. The result of the impact parameter method is τB=1.36±0.13±0.28 ps, that of the vertex method is τB=1.30±0.10±0.28 ps and that of the dipole method is τB=1.47±0.14±0.30 ps. These are combined to give the result τB=1.35±0.10±0.24 ps. © 1989 Springer-Verlag.
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Pion, kaon and proton cross sections in e+e- annihilation at 34 GeV and 44 GeV c.m. energy

Zeitschrift für Physik C Particles and Fields 42:2 (1989) 189-197

Authors:

W Braunschweig, R Gerhards, FJ Kirschfink, HU Martyn, B Bock, HM Fischer, H Hartmann, J Hartmann, E Hilger, A Jocksch, R Wedemeyer, B Foster, AJ Martin, AJ Sephton, F Barreiro, E Bernardi, J Chwastowski, A Eskreys, K Gather, K Genser, H Hultschig, P Joos, H Kowalski, A Ladage, B Lohr, D Lüke, P Mattig, D Notz, JM Pawlak, KU Pösnecker, E Ros, D Trines, R Walczak, G Wolf, H Kolanoski, W Gerhardt, T Kracht, HL Krasemann, J Krüger, E Lohrmann, G Poelz, P Rehders, G Tysarczyk, C Winand, W Zeuner, DM Binnie, J Hassard, J Shulman, D Su, A Leites, J del Peso, C Balkwill, MG Bowler, PN Burrows, R Cashmore, GP Heath, PN Ratoff, IM Silvester, IR Tomalin, ME Veitch, GE Forden, JC Hart, DH Saxon, S Brandt, M Holder, L Labarga, Y Eisenberg, U Karshon, G Mikenberg, A Montag, D Revel, E Ronat, A Shapira, N Wainer, G Yekutieli, A Caldwell, D Muller, S Ritz, D Strom, M Takashima, E Wicklund, S Lan Wu, G Zobernig

Abstract:

The inclusive production of π± and K± mesons and of protons and antiprotons in e+e- annihilations has been measured at 34 GeV and 44 GeV center of mass energy; in addition π± mesons have been measured at 44 GeV c.m. energy. Differential cross sections and particle yields are given. At 34 GeV average multiplicities are: {Mathematical expression} and at 44 GeV: {Mathematical expression} © 1989 Springer-Verlag.
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Production and decay of charmed mesions in e+e- annihilation at {Mathematical expression}

Zeitschrift für Physik C Particles and Fields 44:3 (1989) 365-378

Authors:

W Braunschweig, R Gerhards, FJ Kirschfink, HU Martyn, HM Fischer, H Hartmann, J Hartmann, E Hilger, A Jocksch, R Wedemeyer, B Foster, AJ Martin, E Bernardi, J Chwastowski, A Eskreys, K Gather, K Genser, H Hultschig, P Joos, H Kowalski, A Ladage, B Löhr, D Lüke, P Mättig, D Notz, JM Pawlak, KU Pösnecker, E Ros, D Trines, R Walczak, G Wolf, H Kolanoski, T Kracht, J Krüger, E Lohrmann, G Poelz, W Zeuner, RS Galik, J Hassard, J Shulman, D Su, I Tomalin, A Watson, F Barreiro, A Leites, J del Peso, MG Bowler, PN Burrows, ME Veitch, GE Forden, JC Hart, DH Saxon, S Brandt, M Holder, Y Eisenberg, U Karshon, G Mikenberg, A Montag, D Revel, E Ronat, A Shapira, N Wainer, G Yekutieli, A Caldwell, D Muller, S Ritz, D Strom, M Takashima, SL Wu, G Zobernig

Abstract:

We report on a study of inclusive production of D*± mesons in e+e- annihilation at c.m. energies between 28 and 46.8 GeV using the TASSO detector at the PETRA storage ring. A hard D*± energy spectrum is measured with a maximum near ED*±≃0.6 Ebeam. The measured cross section ratio {Mathematical expression} indicates that D* production accounts for a large fraction of the observed charm production. Two complementary methods have been used to determine the forward-backward asymmetry of charm pair production due to electroweak interference. Combining both measurements the product of the axial vector couplings of the electron and the charm quark to the weak neutral current was determined to be gAegAc=-(0.276±0.073), in agreement with the standard model prediction of -0.25. Using a sample of reconstructed D*± mesons, the relative strength of the strong interaction coupling of the c quark compared to that of an average of all flavours is measured as αs(c)/αs(all)=0.91±0.38±0.15, consistent with the coupling constant being flavour independent. An update of our D0 lifetime measurement is presented, based on a considerable increase in statistics, the final result being {Mathematical expression}. © 1989 Springer-Verlag.
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Study of η production in two-photon collisions

Zeitschrift für Physik C Particles and Fields 41:4 (1989) 533-538

Authors:

W Braunschweig, R Gerhards, FJ Kirschfink, HU Martyn, B Bock, HM Fischer, H Hartmann, J Hartmann, E Hilger, A Jocksch, V Mertens, R Wedemeyer, B Foster, AJ Martin, AJ Sephton, E Bernardi, J Chwastowski, A Eskreys, K Gather, K Genser, H Hultschig, P Joos, H Kowalski, A Ladage, B Löhr, D Lüke, P Märtig, D Notz, JM Pawlak, KU Posnecker, E Ros, D Trines, R Walczak, G Wolf, H Kolanoski, T Kracht, J Krüger, E Lohrmann, G Poelz, W Zeuner, J Hassard, J Shulman, D Su, F Barreiro, A Leites, J del Peso, C Balkwill, MG Bowler, PN Burrows, GP Heath, P Ratoff, I Silvester, I Tomalin, E Veitch, GE Forden, JC Hart, DH Saxon, S Brandt, M Holder, L Labarga, E Duchovni, Y Eisenberg, D Hochman, U Karshon, L Lyons, G Mikenberg, A Montag, D Revel, E Ronat, A Shapira, N Wainer, G Yekutieli, A Caldwell, D Muller, S Ritz, D Strom, M Takashima, E Wicklund, SL Wu, G Zobernig

Abstract:

Production of the ηc meson in e+e- quasireal two photon collisions has been looked for in three channels. The data were obtained from an integrated luminosity of 189 pb-1. An ηc signal is observed in two decay modes (Ks0K±π∓,π+π-π+π-) with a combined statistical significance of 3.5 standard deviations. Using the known ηc branching ratios to these channels and to K+K-π+π- the combined partial ηc width to γγ is Γγγ(ηc). The first error is statistical, and the second one includes the systematic and branching ratio errors. Calculated as an upper limit we obtain Γγγ(ηc) (95% C.L., including the systematic error). © 1989 Springer-Verlag.
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