Experimental studies of unbiased gluon jets from $e^{+}e^{-}$ annihilations using the jet boost algorithm

Abbiendi, G.; Arcelli, S.; Geich-Gimbel, C.; Rozen, Y.; Boutemeur, M.; Burckhart, H.J.; Axen, D.; Scott, W.G.; Mattig, Peter; Warsinsky, M.; Sachs, K.; Fleck, I.; Polok, J.; Giacomelli, G.; Mohr, W.; Meijers, F.; Leins, A.; Boeriu, O.; Patrick, G.N.; Mori, T.; Gunther, P.O.; Mihara, S.; Klier, A.; Akesson, P.F.; Cuffiani, M.; Duckeck, G.; Keeler, R.K.; McPherson, R.A.; Tasevsky, M.; Torrence, E.; Tsur, E.; Gruwe, M.; McMahon, T.J.; Kluth, S.; Batley, R.J.; Shears, T.G.; Tran, P.; Kupper, M.; Quadt, A.; Wermes, N.; Pater, J.R.; Zivkovic, Lidija; Yamashita, S.; Harin-Dirac, M.; Barlow, R.J.; Giunta, Marina; Giacomelli, P.; Duerdoth, I.P.; Grunhaus, J.; Heuer, R.D.; Karapetian, G.; Menges, W.; Alexander, G.; Seuster, R.; Soldner-Rembold, S.; Shen, B.C.; Hoffman, Kara Dion; Poli, B.; Azuelos, G.; Komamiya, S.; Waller, D.; Stephens, K.; Schroder, Matthias; Saeki, T.; Herten, G.; Kim, D.H.; Kawamoto, T.; Nanjo, H.; Bell, Kenneth Watson; Schwick, C.; Anderson, K.J.; Sobie, R.; Bethke, S.; Hanson, G.G.; Ueda, I.; Ujvari, B.; De Roeck, A.; Campana, S.; Mashimo, T.; Roney, J.M.; Dado, S.; Igo-Kemenes, P.; Hajdu, C.; Wilson, J.A.; Hamann, M.; Carnegie, R.K.; Wyatt, T.R.; Bock, P.; Wengler, T.; Nisius, R.; Dienes, B.; Lu, J.; Behnke, T.; Bella, G.; Brigliadori, L.; Scharff-Hansen, P.; Ferrari, P.; Mikenberg, G.; Neal, H.A.; Okpara, A.; Kobayashi, T.; Furtjes, A.; Ludwig, J.; Levinson, L.; Letts, J.; Marcellini, S.; O'Neale, S.W.; Biebel, O.; von Krogh, J.; Martin, A.J.; Kormos, Laura L.; Pooth, O.; Duchovni, E.; Bechtle, P.; Fabbri, F.; Krieger, P.; Kobel, M.; Hill, J.C.; Hauschild, M.; Turner-Watson, M.F.; Lillich, J.; Renkel, P.; Kanzaki, J.; Watson, A.T.; Macpherson, A.; McDonald, W.J.; Bell, P.J.; Lloyd, S.L.; Buesser, K.; Barberio, E.; Anagnostou, G.; Gary, John William; Kennedy, B.W.; Caron, B.; Wetterling, D.; Vannerem, P.; Siroli, G.; Watkins, P.M.; Brown, Robert M.; Fiedler, F.; Harder, K.; Bellerive, A.; Mader, W.; De Wolf, E.A.; Hawkes, C.M.; Harel, A.; Loebinger, F.K.; Strohmer, R.; Verzocchi, M.; Dubbert, J.; Pasztor, G.; Ishii, K.; Przybycien, M.; Rosati, S.; Vertesi, R.; Rembser, C.; Lellouch, D.; Masetti, G.; Stahl, A.; Spano, F.; Carter, J.R.; Moed, S.; Ford, M.; Horvath, D.; Schumacher, M.; Schaile, A.D.; Trigger, I.; Gagnon, P.; Plane, David E.; Toya, D.; Wilson, G.W.; Donkers, M.; Oh, A.; Hensel, C.; Miller, D.J.; Gross, E.; Thomson, M.A.; Watson, N.K.; Junk, T.R.; Taylor, R.J.; Kramer, T.; Sherwood, P.; Ward, C.P.; Klein, K.; Sarkisyan, E.K.G.; Mutter, A.; Feld, L.; Rabbertz, K.; Kellogg, R.G.; Layter, J.G.; Kuhl, T.; Carter, A.A.; Mes, H.; Teuscher, R.; Asai, S.; Nakamura, I.; Schoerner-Sadenius, Thomas; Chang, C.Y.; Tarem, S.; Jovanovic, P.; Etzion, E.; Pahl, C.; Hawkings, R.; Merritt, F.S.; Rick, H.; Strom, David M.; Orito, S.; Ainsley, C.; Runge, K.; Smith, A.M.; Csilling, A.; Pinfold, J.; Gaycken, G.; Goldberg, J.; Vossebeld, J.; Schieck, J.; Desch, K.; Vollmer, C.F.; Gupta, A.; Nagai, K.; Benelli, G.; Bailey, I.; Lanske, D.; Ward, D.R.; Skuja, A.; Karlen, D.; Amaral, P.; McKenna, J.; Oreglia, M.J.; Hemingway, R.J.; Jeremie, H.; Kruger, K.; Zer-Zion, D.; Voss, H.; Kawagoe, K.; Michelini, A.; Kanaya, N.; Landsman, H.; Schaile, O.; Braibant, S.; Allison, John; Wells, P.S.; Wolf, G.; Charlton, David G.; Lafferty, G.D.; Frey, A.; Trocsanyi, Z.; Pilcher, J.E.

doi:10.1103/PhysRevD.69.032002

Article
Report number	hep-ex/0310048 ; CERN-EP-2003-067 ; CERN-EP-2003-067
Title	Experimental studies of unbiased gluon jets from $e^{+}e^{-}$ annihilations using the jet boost algorithm
Author(s)	Abbiendi, G. ; Ainsley, C. ; Akesson, P.F. ; Alexander, G. ; Allison, John ; Amaral, P. ; Anagnostou, G. ; Anderson, K.J. ; Arcelli, S. ; Asai, S. ; Axen, D. ; Azuelos, G. ; Bailey, I. ; Barberio, E. ; Barlow, R.J. ; Batley, R.J. ; Bechtle, P. ; Behnke, T. ; Bell, Kenneth Watson ; Bell, P.J. ; Bella, G. ; Bellerive, A. ; Benelli, G. ; Bethke, S. ; Biebel, O. ; Boeriu, O. ; Bock, P. ; Boutemeur, M. ; Braibant, S. ; Brigliadori, L. ; Brown, Robert M. ; Buesser, K. ; Burckhart, H.J. ; Campana, S. ; Carnegie, R.K. ; Caron, B. ; Carter, A.A. ; Carter, J.R. ; Chang, C.Y. ; Charlton, David G. ; Csilling, A. ; Cuffiani, M. ; Dado, S. ; De Roeck, A. ; De Wolf, E.A. ; Desch, K. ; Dienes, B. ; Donkers, M. ; Dubbert, J. ; Duchovni, E. ; Duckeck, G. ; Duerdoth, I.P. ; Etzion, E. ; Fabbri, F. ; Feld, L. ; Ferrari, P. ; Fiedler, F. ; Fleck, I. ; Ford, M. ; Frey, A. ; Furtjes, A. ; Gagnon, P. ; Gary, John William ; Gaycken, G. ; Geich-Gimbel, C. ; Giacomelli, G. ; Giacomelli, P. ; Giunta, Marina ; Goldberg, J. ; Gross, E. ; Grunhaus, J. ; Gruwe, M. ; Gunther, P.O. ; Gupta, A. ; Hajdu, C. ; Hamann, M. ; Hanson, G.G. ; Harder, K. ; Harel, A. ; Harin-Dirac, M. ; Hauschild, M. ; Hawkes, C.M. ; Hawkings, R. ; Hemingway, R.J. ; Hensel, C. ; Herten, G. ; Heuer, R.D. ; Hill, J.C. ; Hoffman, Kara Dion ; Horvath, D. ; Igo-Kemenes, P. ; Ishii, K. ; Jeremie, H. ; Jovanovic, P. ; Junk, T.R. ; Kanaya, N. ; Kanzaki, J. ; Karapetian, G. ; Karlen, D. ; Kawagoe, K. ; Kawamoto, T. ; Keeler, R.K. ; Kellogg, R.G. ; Kennedy, B.W. ; Kim, D.H. ; Klein, K. ; Klier, A. ; Kluth, S. ; Kobayashi, T. ; Kobel, M. ; Komamiya, S. ; Kormos, Laura L. ; Kramer, T. ; Krieger, P. ; von Krogh, J. ; Kruger, K. ; Kuhl, T. ; Kupper, M. ; Lafferty, G.D. ; Landsman, H. ; Lanske, D. ; Layter, J.G. ; Leins, A. ; Lellouch, D. ; Letts, J. ; Levinson, L. ; Lillich, J. ; Lloyd, S.L. ; Loebinger, F.K. ; Lu, J. ; Ludwig, J. ; Macpherson, A. ; Mader, W. ; Marcellini, S. ; Martin, A.J. ; Masetti, G. ; Mashimo, T. ; Mattig, Peter ; McDonald, W.J. ; McKenna, J. ; McMahon, T.J. ; McPherson, R.A. ; Meijers, F. ; Menges, W. ; Merritt, F.S. ; Mes, H. ; Michelini, A. ; Mihara, S. ; Mikenberg, G. ; Miller, D.J. ; Moed, S. ; Mohr, W. ; Mori, T. ; Mutter, A. ; Nagai, K. ; Nakamura, I. ; Nanjo, H. ; Neal, H.A. ; Nisius, R. ; O'Neale, S.W. ; Oh, A. ; Okpara, A. ; Oreglia, M.J. ; Orito, S. ; Pahl, C. ; Pasztor, G. ; Pater, J.R. ; Patrick, G.N. ; Pilcher, J.E. ; Pinfold, J. ; Plane, David E. ; Poli, B. ; Polok, J. ; Pooth, O. ; Przybycien, M. ; Quadt, A. ; Rabbertz, K. ; Rembser, C. ; Renkel, P. ; Rick, H. ; Roney, J.M. ; Rosati, S. ; Rozen, Y. ; Runge, K. ; Sachs, K. ; Saeki, T. ; Sarkisyan, E.K.G. ; Schaile, A.D. ; Schaile, O. ; Scharff-Hansen, P. ; Schieck, J. ; Schoerner-Sadenius, Thomas ; Schroder, Matthias ; Schumacher, M. ; Schwick, C. ; Scott, W.G. ; Seuster, R. ; Shears, T.G. ; Shen, B.C. ; Sherwood, P. ; Siroli, G. ; Skuja, A. ; Smith, A.M. ; Sobie, R. ; Soldner-Rembold, S. ; Spano, F. ; Stahl, A. ; Stephens, K. ; Strom, David M. ; Strohmer, R. ; Tarem, S. ; Tasevsky, M. ; Taylor, R.J. ; Teuscher, R. ; Thomson, M.A. ; Torrence, E. ; Toya, D. ; Tran, P. ; Trigger, I. ; Trocsanyi, Z. ; Tsur, E. ; Turner-Watson, M.F. ; Ueda, I. ; Ujvari, B. ; Vollmer, C.F. ; Vannerem, P. ; Vertesi, R. ; Verzocchi, M. ; Voss, H. ; Vossebeld, J. ; Waller, D. ; Ward, C.P. ; Ward, D.R. ; Warsinsky, M. ; Watkins, P.M. ; Watson, A.T. ; Watson, N.K. ; Wells, P.S. ; Wengler, T. ; Wermes, N. ; Wetterling, D. ; Wilson, G.W. ; Wilson, J.A. ; Wolf, G. ; Wyatt, T.R. ; Yamashita, S. ; Zer-Zion, D. ; Zivkovic, Lidija
Affiliation	(School of Phys. and Astronomy, Univ. Birmingham) ; (Dipartimento di Fis. dell Univ. Bologna and INFN) ; (Phys. Institut, Univ. Bonn) ; (Department of Phys., Univ. California) ; (Cavendish Laboratory, Cambridge) ; (Ottawa-Carleton Institute for Phys., Dept. of Phys., Carleton Univ.) ; (CERN) ; (Enrico Fermi Institute and Department of Phys., Univ. Chicago) ; (Fakultat fur Phys., Albert Ludwigs Univ., Freiburg) ; (Phys. Institut, Univ. Heidelberg) ; (Indiana Univ., Department of Phys.) ; (Queen Mary and Westfield College, Univ. London,) ; (Technische Hochschule Aachen, III Phys. Institut, Aachen) ; (Univ. College London) ; (Department of Phys., Schuster Laboratory, Manchester) ; (Department of Phys., Univ. Maryland) ; (Laboratoire de Phys. Nucl., Univ. Montreal) ; (Univ. Oregon, Department of Phys.) ; (CLRC Rutherford Appleton Laboratory) ; (Department of Phys., Technion-Israel Institute of Technology) ; (Department of Phys. and Astronomy, Tel Aviv Univ.) ; (International Centre for Elementary Particle Phys. and Department of Phys., Univ. Tokyo) ; (Kobe Univ.) ; (Particle Phys. Department, Weizmann Institute of Science) ; (Univ. Hamburg/DESY) ; (Univ. Victoria, Department of Phys.) ; (Univ. British Columbia, Department of Phys.) ; (Univ. Alberta, Department of Phys.) ; (Research Institute for Part. and Nucl. Phys., Budapest) ; (Institute of Nucl. Research, Hungary) ; (Ludwigs-Maximilians-Univ. Munchen) ; (Max-Planck-Institut fur Physik, Munich) ; (Yale Univ., Department of Phys.) ; (TRIUMF)
Publication	2004
Imprint	9 Oct 2003
Number of pages	41
In:	Phys. Rev. D 69 (2004) 032002
DOI	10.1103/PhysRevD.69.032002
Subject category	Particle Physics - Experiment
Accelerator/Facility, Experiment	CERN LEP ; OPAL
Abstract	We present the first experimental results based on the jet boost algorithm, a technique to select unbiased samples of gluon jets in e+e- annihilations, i.e. gluon jets free of biases introduced by event selection or jet finding criteria. Our results are derived from hadronic Z0 decays observed with the OPAL detector at the LEP e+e- collider at CERN. First, we test the boost algorithm through studies with Herwig Monte Carlo events and find that it provides accurate measurements of the charged particle multiplicity distributions of unbiased gluon jets for jet energies larger than about 5 GeV, and of the jet particle energy spectra (fragmentation functions) for jet energies larger than about 14 GeV. Second, we apply the boost algorithm to our data to derive unbiased measurements of the gluon jet multiplicity distribution for energies between about 5 and 18 GeV, and of the gluon jet fragmentation function at 14 and 18 GeV. In conjunction with our earlier results at 40 GeV, we then test QCD calculations for the energy evolution of the distributions, specifically the mean and first two non-trivial normalized factorial moments of the multiplicity distribution, and the fragmentation function. The theoretical results are found to be in global agreement with the data, although the factorial moments are not well described for jet energies below about 14 GeV.
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