Laser-plasma accelerator group

Research group

Research theme

Sub department

About

Study of intermittency in electron-positron annihilation into hadrons

Physics Letters B 231:4 (1989) 548-556

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 Genser, H Hultschig, P Joos, H Kowalski, A Ladage, B Löhr, D Lüke, 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, D Binnie, J Hassard, J Shulman, D Su, I Tomalin, F Barreiro, A Leites, J Del Peso, PN Burrows, 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, A Caldwell, D Muller, S Ritz, M Takashima, S Lan Wu, G Zobernig

Abstract:

Intermittency effects have been studied directly for the first time in e+e- annihilation, using 37 509 hadronic events at an average CM energy of 〈√s〉=35 GeV. The factorial moments F2, F3 and F4 are given for the rapidity distribution and for the two-dimensional distributions in rapidity and azimuthal angle. The effects of cuts in sphericity and particle momentum are large. Comparison with several fragmentation models are made; some models like the Lund model with O(αs2) matrix element give a qualitative description of the phenomena. The importance of detector effects is demonstrated. The results are discussed in terms of various suggested interpretations of this effect. © 1989.
More details from the publisher
More details

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

Zeitschrift für Physik C Particles and Fields 42:2 (1989) 348

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
More details from the publisher

Strange baryon production in e+e- annihilation

Zeitschrift für Physik C Particles and Fields 45:2 (1989) 209-222

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 Mattig, D Notz, JM Pawlak, KU Posnecker, E Ros, W Schütte, D Trines, R Walczak, G Wolf, H Kolanoski, T Kracht, J Krüger, E Lohrmann, G Poelz, W Zeuner, DM Binnie, J Hassard, J Shulman, D Su, F Barreiro, A Leites, L Hervas, J del Peso, M Traseira, C Balkwill, MG Bowler, PN Burrows, RJ Cashmore, GP Heath, PN Ratoff, IM Silvester, IR Tomalin, ME Veitch, JM Yelton, SL Lloyd, 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 production of strange baryons in e+e- annihilation has been studied at centre of mass energies of 34.8 GeV and 42.1 GeV, using the TASSO detector at DESY. Inclusive cross-sections have been obtained for Λ0 and Ξ- production and an upper limit has been placed upon the production rate of Σ*±(1385). We measure the Λ0 multiplicity per event to be {Mathematical expression} and {Mathematical expression} at {Mathematical expression} and 42.1 GeV respectively. The Ξ- multiplicity per event is found to be {Mathematical expression} at {Mathematical expression}. An investigation has been made of the extent to which Λ0 are produced in pairs. The Λ0 cross-section has been studied as a function of event sphericity. © 1989 Springer-Verlag.
More details from the publisher
More details

Experimental study of jet masses in e+e- annihilation at c.m. energies between 12 and 43.5 GeV

Zeitschrift für Physik C Particles and Fields 45:1 (1989) 11-23

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, F Barreiro, E Bernardi, J Chwastowski, K Genser, H Kowalski, B Löhr, D Lüke, D Notz, JM Pawlak, KU Pösnecker, E Ros, R Walczak, G Wolf, H Kolanoski, T Kracht, J Krüger, E Lohrmann, G Poelz, W Zeuner, A Hassard, J Shulman, D Su, I Tomalin, A Leites, J del Peso, L Hervas, M Traseira, MG Bowler, PN Burrows, RJ Cashmore, GP Heath, ME Veitch, JC Hart, DH Saxon, S Brandt, M Holder, L Labarga, Y Eisenberg, U Karshon, G Mikenberg, A Montag, D Revel, E Ronat, AN Wainer, G Yekutieli, D Muller, S Ritz, M Takashima, SL Wu, G Zobernig, A Caldwell

Abstract:

Data on jet masses, resulting from the decomposition of e+e- hadronic final states into two hemispheres, are presented at centre of mass energies between 12 and 43.5 GeV. Comparisons are made with bare O(αs2) QCD predictions as well as with QCD based fragmentation models. Values for αs and {Mathematical expression} are determined, both with and without hadronization effects included. Upper and lower limits for {Mathematical expression} independent of fragmentation models have been determined to be 0.480±0.025 GeV and 0.047±0.007 GeV respectively. © 1989 Springer-Verlag.
More details from the publisher
More details

A study of jets from b quarks produced in e+e- annihilations at {Mathematical expression} GeV

Zeitschrift für Physik C Particles and Fields 42:1 (1989) 17-31

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 Mattig, D Notz, J Pawlak, KU Pösnecker, E Ros, W Schütte, D Trines, R Walczak, G Wolf, H Kolanoski, T Kracht, J Krüger, E Lohrmann, G Poelz, W Zeuner, AT Belk, DM Binnie, JF Hassard, J Shulman, D Su, F Barreiro, A Leites, J del Peso, C Balkwill, MG Bowler, PN Burrows, RJ Cashmore, GP Heath, P Ratoff, IM Silvester, I Tomalin, ME Veitch, JM Yelton, SL Lloyd, 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:

A b enrichment technique using the long B lifetime has been developed, by which ∼600 hadronic events with >65%b purity are obtained. The properties of the associated jets are studied, with comparisons made between them and those in hadronic data in which b quarks make up only 10% of the total, and jets in Monte Carlo events. The distributions in rapidity and multiplicity yield two new determinations of the fragmentation variable z for b hadrons and confirm that the b fragmentation function is hard. We also present the first measurement of the relative strength of the strong interaction coupling of the b quark compared with the average of all flavours. © 1989 Springer-Verlag.
More details from the publisher