Investigation of the total charm-pair cross section in nonresonant e+e- annihilations at sqrt s =10.5 GeV.

Physical review. D, Particles and fields 38:9 (1988) 2679-2686

Authors:

T Bowcock, K Kinoshita, FM Pipkin, M Procario, R Wilson, J Wolinski, D Xiao, P Haas, M Hempstead, T Jensen, DR Johnson, H Kagan, R Kass, FM Morrow, P Baringer, RL McIlwain, DH Miller, CR Ng, EI Shibata, R Poling, MS Alam, N Katayama, IJ Kim, WC Li, XC Lou, CR Sun, V Tanikella, D Bortoletto, M Goldberg, R Holmes, N Horwitz, A Jawahery, GC Moneti, V Sharma, IP Shipsey, SE Csorna, MD Mestayer, IC Brock, T Ferguson, H Vogel, C Bebek, K Berkelman, E Blucher, J Byrd, DG Cassel, DM Coffman, T Copie, R DeSalvo, JW DeWire, R Ehrlich, RS Galik, B Gittelman, SW Gray, AM Halling, DL Hartill, BK Heltsley, J Kandaswamy, R Kowalewski, DL Kreinick, Y Kubota, JD Lewis, NB Mistry, J Mueller, R Namjoshi

Evidence for direct photons from quarks in electron-positron annihilation

Zeitschrift für Physik C Particles and Fields 41:3 (1988) 385-393

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, T Tymieniecka, R Walczak, G Wolf, H Kolanoski, W Gerhardt, T Kracht, J Krüger, E Lohrmann, G Poelz, P Rehders, G Tysarczyk, W Zeuner, J Hassard, J Shulman, D Su, A Leites, J del Peso, C Balkwill, MG Bowler, PN Burrows, GP Heath, P Ratoff, I 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, D Muller, S Ritz, D Strom, M Takashima, SL Wu, G Zobernig

Abstract:

Hadronic events from e+e--annihilations with a high energy isolated photon have been investigated at C.M. energies between 14 GeV and 44 GeV. A forward-backward asymmetry Aγ of the positively charged jet with respect to the incident positron direction has been found:Aγγ=-0.32±0.07, providing evidence for photon bremsstrahlung from quarks. The forward-backward asymmetry of all hadronic events at C.M. energies between 30 GeV and 36 GeV has been measured. The value, corrected for the limited polar angle acceptance of the detector, is:A=+0.021±0.005. © 1988 Springer-Verlag.

Jet fragmentation and QCD models in e+e- annihilation at c.m. energies between 12.0 and 41.5 GeV

Zeitschrift für Physik C Particles and Fields 41:3 (1988) 359-373

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, 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, J Hassard, J Shulman, D Su, F Barreiro, 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, D Muller, S Ritz, D Strom, M Takashima, SL Wu, G Zobernig

Abstract:

The large amount of data accumulated by the TASSO detector at 35 GeV c.m. energy has been compared with the predictions of the latest generation of perturbative QCD+fragmentation models. By adjustment of the arbitrary parameters of these models, a very good description of the global properties of hadronic events was obtained. No one model gave the best description of all features of the data, each model being better than the others for some observables and worse in other quantities. We interpret these results in terms of the underlying QCD and hadronisation schemes. The trends of the data across the energy range 12.0≦W≦41.5 GeV are generally well reproduced by the models with the parameters optimised at 35 GeV. © 1988 Springer-Verlag.

Performance of a prototype drift Chamber with 100 MHz FADC readout

Nuclear Inst. and Methods in Physics Research, A 270:2-3 (1988) 373-386

Authors:

SM Tkaczyk, JA Blissett, JC Hart, DK Hasell, AG Parham, BT Payne, JHC Roberts, DH Saxon, B Foster, RS Gilmore, J Malos, RJ Tapper, N Wilkinson

Abstract:

Rectangular drift chamber cells have been constructed and tested using an electron test beam facility at DESY. A systematic study of the time, spatial, energy and double track resolutions with a 100 MHz FADC readout is presented. The spatial resolution is 100 to 120 μm and the double track resolution is 2.5 mm with an Ar:C2H6 (50:50) gas mixture at atmospheric pressure. The dE dx resolution obtained corresponds to 6% resolution for a 72-layer chamber. © 1988.

A measurement of muon pair production in e+e- annihilation at centre of mass energies 35.0≤ {Mathematical expression}≤46.8 GeV

Zeitschrift für Physik C Particles and Fields 40:2 (1988) 163-170

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, 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, J Hassard, J Shulman, D Su, F Barreiro, L Hervas, A Leites, J del Peso, M Traseira, C Balkwill, MG Bowler, PN Burrows, RJ Cashmore, CM Hawkes, GP Heath, PN Ratoff, IM Silvester, IR Tomalin, ME Veitch, GE Forden, JC Hart, DH Saxon, S Brandt, M Holder, L Labarga, E Duchovni, Y Eisenberg, U Karshon, G Mikenberg, A Montag, D Revel, E Ronat, AN Wainer, G Yekutieli, D Muller, S Ritz, D Strom, M Takashima, SL Wu, G Zobernig

Abstract:

The reaction e+e-→μ+μ- has been studied at centre of mass energies between 35.0 and 46.8 GeV using the TASSO detector at PETRA. We present measurements of the forward-backward charge asymmetry (Aμμ) and cross section σμμ for this reaction at three energies. At 35.0 GeV we obtain a cross section relative to the QED prediction of Rμμ=σμμ/σo=0.932±0.018±0.044 and Aμμ=(-10.6-2.3+2.2±0.5)%. At 38.3 GeV we find Rμμ=0.951±0.072-0.057+0.063 and Aμμ=(+1.7-8.6+8.5±0.5)%. At 43.6 GeV we measure Rμμ=0.921±0.037±0.055 and Aμμ=(-17.6-4.3+4.4±0.5)%. Our results are in good agreement with the predictions of the standard model. Including previous TASSO data we present improved determinations of muonic electroweak parameters. We also report on lower limits of possible contributions from contact interactions. © 1988 Springer-Verlag.