Plasma-Wakefield Accelerator Group: publications

Measurement of R and search for the top quark in e⁺e^- annihilation between 39.8 and 45.2 GeV

Physics Letters B 138:5-6 (1984) 441-448

Authors:

M Althoff, W Braunschweig, FJ Kirschfink, K Lübelsmeyer, HU Martyn, G Peise, J Rimkus, P Rosskamp, HG Sander, D Schmitz, H Siebke, W Wallraff, HM Fischer, H Hartmann, W Hillen, A Jocksch, G Knop, L Köpke, H Kolanoski, H Kück, V Mertens, R Wedemeyer, M Wollstadt, Y Eisenberg, K Gather, H Hultschig, P Joos, U Kötz, H Kowalski, A Ladage, B Löhr, D Lüke, P Mättig, D Notz, RJ Nowak, J Pyrlik, M Rushton, W Schütte, D Trines, G Wolf, C Xiao, R Fohrmann, E Hilger, T Kracht, HL Krasemann, P Leu, E Lohrmann, D Pandoulas, G Poelz, KU Pösnecker, BH Wiik, R Beuselinck, DM Binnie, AJ Campbell, PJ Dornan, B Foster, DA Garbutt, C Jenkins, TD Jones, WG Jones, J McCardle, JK Sedgbeer, J Thomas, WAT Wan Abdullah, KW Bell, MG Bowler, P Bull, RJ Cashmore, PEL Clarke, R Devenish, P Grossmann, CM Hawkes, SL Lloyd, GL Salmon, TR Wyatt, C Youngman, GE Forden, JC Hart, J Harvey, DK Hasell, J Proudfoot, DH Saxon, F Barreiro, M Dittmar, M Holder, G Kreutz, B Neumann, E Duchovni, U Karshon, G Mikenberg, R Mir, D Revel, E Ronat, A Shapira, G Yekutieli, G Baranko, T Barklow, A Caldwell, M Cherney, JM Izen

Abstract:

e+e- annihilation into hadrons was studied at CM energies between 39.8 and 45.2 GeV and a search was made for new heavy quarks. No evidence was found for the existence of a narrow state excluding the possible existence of the lowest vector toponium state in this mass range. A search for continuum production of heavy quarks led to lower mass limits for new quarks of 22.0 GeV (eQ = 2 3) and 21.0 GeV (eQ = 1 3). Quarks are found to be pointlike, the corresponding mass parameter being larger than 288 GeV. A fit of the QCD and the electroweak contributions to R=σtot/σμμ yielded sin2θW = 0.30-0.07+0.23. © 1984.

Experimental test of the flavor independence of the quark-gluon coupling constant

Physics Letters B 138:4 (1984) 317-324

Authors:

M Althoff, W Braunschweig, FJ Kirschfink, K Lübelsmeyer, HU Martyn, J Rimkus, P Rosskamp, HG Sander, D Schmitz, H Siebke, W Wallraff, HM Fischer, H Hartmann, A Jocksch, G Knop, L Köpke, H Kolanoski, H Kück, V Mertens, R Wedemeyer, M Wollstadt, Y Eisenberg, A Eskreys, K Gather, H Hultschig, P Joos, U Kötz, H Kowalski, A Ladage, B Löhr, D Lüke, P Mättig, D Notz, RJ Nowak, J Pyrlik, M Rushton, W Schütte, D Trines, G Wolf, C Xiao, R Fohrmann, E Hilger, T Kracht, HL Krasemann, P Leu, E Lohrmann, D Pandoulas, G Poelz, KU Pösnecker, BH Wiik, R Beuselinck, DM Binnie, AJ Campbell, P Dornan, B Foster, DA Garbutt, C Jenkins, TD Jones, WG Jones, J McCardle, JK Sedgbeer, J Thomas, WAT Wan Abdullah, KW Bell, MG Bowler, P Bull, RJ Cashmore, PEL Clarke, R Devenish, P Grossmann, CM Hawkes, SL Lloyd, GL Salmon, TR Wyatt, C Youngman, GE Forden, JC Hart, J Harvey, DK Hasell, J Proudfoot, DH Saxon, F Barreiro, M Dittmar, M Holder, G Kreutz, B Neumann, E Duchovni, U Karshon, G Mikenberg, R Mir, D Revel, E Ronat, A Shapira, G Yekutieli, G Baranko, T Barklow, A Caldwell, M Cherney, JM Izen, M Mermikides

Abstract:

Reconstruction of charged D^*'s produced inclusively in e⁺e-. annihilation at CM energies near 34.4 GeV is accomplished in the decay modes D*⁺→D⁰π⁺→K^-gp⁺π⁰π⁺ and D*⁺→D⁰π⁺→ K^-gp⁺π^-π⁺π⁺ and their charge conjugates. Using these and previously reported D*⁺→D⁰π⁺→K^-gp⁺π⁺ and D*⁺→D⁰π⁺→ K^-gp⁺π⁺ + missing π⁰ channels we present evidence for hard gluon bremsstrahlung from charm quarks and show that the ratio of the quark-gluon coupling constant of charm quarks to the coupling constant obtained in the average hadronic event, αs^c αrms = 100 ± 0.20 ± 1.20. Our result provides evidence that the quark-gluon coupling constant is independent of flavor. © 1984.

Observation of hard processes in collisions of two quasi-real photons

Physics Letters B 138:1-3 (1984) 219-224

Authors:

M Althoff, W Braunschweig, FJ Kirschfink, K Lübelsmeyer, HU Martyn, G Peise, J Rimkus, P Rosskamp, HG Sander, D Schmitz, H Siebke, W Wallraff, HM Fischer, H Hartmann, W Hillen, A Jocksch, G Knop, L Köpke, H Kolanoski, H Kück, V Mertens, R Wedemeyer, N Wermes, M Wollstadt, Y Eisenberg, K Gather, H Hultschig, P Joos, W Koch, U Kötz, H Kowalsi, A Ladage, B Löhr, D Lüke, P Mättig, D Notz, RJ Nowak, J Pyrlik, DR Quarrie, M Rushton, W Schütte, D Trines, G Wolf, C Xiao, R Fohrmann, E Hilger, T Kracht, HL Krasemann, P Leu, E Lohrmann, D Pandoulas, G Poelz, BH Wiik, R Beuselinck, DM Binnie, AL Campbell, PJ Dornan, B Foster, DA Garbutt, C Jenkins, TD Jones, WG Jones, J McCardle, JK Sedgbeer, J Thomas, WAT Wan Abdullah, KW Bell, MG Bowler, P Bull, RJ Cashmore, PEL Clarke, R Devenish, P Grossmann, CM Hawkes, SL Lloyd, GL Salmon, TR Wyatt, C Youngman, GE Forden, JC Hart, J Harvey, DK Hasell, J Proudfoot, DH Saxon, PL Woodworth, F Barreiro, M Dittmar, M Holder, B Neumann, E Duchovni, U Karshon, G Mikenberg, R Mir, D Revel, E Ronat, A Shapira, G Yekutieli, T Barklow, A Caldwell, M Cherney

Abstract:

Hard processes in photon-photon collisions are studied using high statistics data without requiring an electron tag. A high yield of hadrons with pt in the range 1.5-3.0 GeV/c is observed. This yield exceeds the expectation of the Born term by a factor of four. © 1984.

Observation of F meson production in high energy e⁺e^- annihilation

Physics Letters B 136:1-2 (1984) 130-134

Authors:

M Althoff, W Braunschweig, FJ Kirschfink, K Lübelsmeyer, HU Martyn, G Peise, J Rimkus, P Rosskamp, HG Sander, D Schmitz, H Siebke, W Wallraff, HM Fischer, H Hartmann, W Hillen, A Jocksch, G Knop, L Köpke, H Kolanoski, H Kück, V Mertens, R Wedemeyer, N Wermes, M Wollstadt, Y Eisenberg, K Gather, H Hultschig, P Joos, W Koch, U Kötz, H Kowalski, A Ladage, B Löhr, D Lüke, P Mättig, D Notz, RJ Nowak, J Pyrlik, DR Quarrie, M Rushton, W Schütte, D Trines, G Wolf, C Xiao, R Fohrmann, E Hilger, T Kracht, HL Krasemann, P Leu, E Lohrmann, D Pandoulas, G Poelz, BH Wiik, R Beuselinck, DM Binnie, AJ Campbell, PJ Dornan, B Foster, DA Garbutt, C Jenkins, TD Jones, WG Jones, J McCardle, JK Sedgbeer, J Thomas, WAT Wan Abdullah, KW Bell, MG Bowler, P Bull, RJ Cashmore, PEL Clarke, R Devenish, P Grossmann, CM Hawkes, SL Lloyd, GL Salmon, TR Wyatt, C Youngman, GE Forden, JC Hart, J Harvey, DK Hasell, J Proudfoot, DH Saxon, PL Woodworth, F Barreiro, M Dittmar, M Holder, B Neumann, E Duchovni, U Karshon, G Mikenberg, R Mir, D Revel, E Ronat, A Shapira, G Yekutieli, G Baranko, T Barklow, A Caldwell

Abstract:

Production of the F meson by e+e- annihilation at high energies has been obsrved in the φ{symbol}π final state with a mass of 1.975 ± 0.009 ± 0.010 GeV and a width consistent with the mass resolution. The yield of F production times branching ratio relative to μ pair production is RF(x ≥ 0.3) B (F± → φ{symbol}π±) = 0.061 ± 0.012 ± 0.018. © 1984.

Properties of charm jets produced in e+e- annihilation near 34 GeV

Physics Letters B 135:1-3 (1984) 243-249

Authors:

M Althoff, W Braunschweig, FJ Kirschfink, K Lübelsmeyer, HU Martyn, G Peise, J Rimkus, P Rosskamp, HG Sander, D Schmitz, H Siebke, W Wallraff, HM Fischer, H Hartmann, W Hillen, A Jocksch, G Knop, L Köpke, H Kolanoski, H Kück, R Wedemeyer, N Wermes, M Wollstadt, Y Eisenberg, K Gather, H Hultschig, P Joos, W Koch, U Kötz, H Kowalski, A Ladage, B Löhr, D Lüke, P Mättig, D Notz, RJ Nowak, J Pyrlik, DR Quarrie, M Rushton, W Schütte, D Trines, G Wolf, C Xiao, R Fohrmann, E Hilger, T Kracht, HL Krasemann, P Leu, E Lohrmann, D Pandoulas, G Poelz, BH Wiik, R Beuselinck, DM Binnie, AL Campbell, PJ Dornan, B Foster, DA Garbutt, C Jenkins, TD Jones, WG Jones, J McCardle, JK Sedgbeer, J Thomas, WAT Wan Abdullah, KW Bell, MG Bowler, P Bull, RJ Cashmore, PEL Clarke, R Devenish, P Grossmann, CM Hawkes, SL Lloyd, GL Salmon, TR Wyatt, C Youngman, GE Forden, JC Hart, J Harvey, DK Hasell, J Proudfoot, DH Saxon, PL Woodworth, F Barreiro, M Dittmar, M Holder, B Neumann, E Duchovni, U Karshon, G Mikenberg, R Mir, D Revel, E Ronat, A Shapira, G Yekutieli, T Barklow, A Caldwell, M Cherney, JM Izen

Abstract:

D^*± production via e⁺e^- → D^*±X was studied at CM energies near 34 GeV. The charged particles produced in the hemisphere opposite to that of the D^* were used to investigate the fragmentation of charm jets. All spectra studied show a close similarity between the charm jet and the average jet obtained by summing over all quark flavours. The spectra of particles produced in the D^* hemisphere were used to study separately first rank and higher rank fragmentation. © 1984.

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