QCD coherence and correlations of particles with restricted momenta in hadronic Z decays

Abstract

QCD coherence effects are studied based on measurements of correlations of particles with either restricted transverse momenta, pT < p cut T , where pT is defined with respect to the thrust axis, or restricted absolute momenta, p ≡ |p| < p , using about four million hadronic Z decays recorded at LEP with the OPAL detector. The correlations are analyzed in terms of normalized factorial and cumulant moments. The analysis is inspired by analytical QCD calculations which, in conjunction with Local Parton-Hadron Duality (LPHD), predict that, due to colour coherence, the multiplicity distribution of particles with restricted transverse momenta should become Poissonian as p cut T decreases. The expected correlation pattern is indeed observed down to p cut T ≈ 1 GeV but not at lower transverse momenta. Furthermore, for p cut → 0 GeV a strong rise is observed in the data, in disagreement with theoretical expectation. The Monte Carlo models reproduce well the measurements at large p cut T and p cut but underestimate their magnitudes at the lowest momenta. The ee data are also compared to the measurements in deep-inelastic ep collisions. Our study indicates difficulties with the LPHD hypothesis when applied to many-particle inclusive observables of soft hadrons. Submitted to Physics Letters B The OPAL Collaboration G.Abbiendi, C.Ainsley, P.F. Åkesson , G.Alexander, G.Anagnostou, K.J.Anderson, S.Asai, D.Axen, I. Bailey, E. Barberio, T.Barillari, R.J. Barlow, R.J. Batley, P. Bechtle, T.Behnke, K.W.Bell, P.J. Bell, G.Bella, A.Bellerive, G.Benelli, S. Bethke, O.Biebel, O.Boeriu, P. Bock, M.Boutemeur, S. Braibant, R.M.Brown, H.J. Burckhart, S. Campana, P.Capiluppi, R.K.Carnegie, A.A.Carter, J.R.Carter, C.Y.Chang, D.G.Charlton, C.Ciocca, A.Csilling, M.Cuffiani, S.Dado, A.De Roeck, E.A.De Wolf, K.Desch, B.Dienes, J.Dubbert, E.Duchovni, G.Duckeck, I.P.Duerdoth, E. Etzion, F. Fabbri, P. Ferrari, F. Fiedler, I. Fleck, M.Ford, A. Frey, P.Gagnon, J.W.Gary, C.Geich-Gimbel, G.Giacomelli, P.Giacomelli, M.Giunta, J.Goldberg, E.Gross, J.Grunhaus, M.Gruwé, P.O.Günther, A.Gupta, C.Hajdu, M.Hamann, G.G.Hanson, A.Harel, M.Hauschild, C.M.Hawkes, R.Hawkings, G.Herten, R.D.Heuer, J.C.Hill, D.Horváth, P. Igo-Kemenes, K. Ishii, H. Jeremie, P. Jovanovic, T.R. Junk, J.Kanzaki, D.Karlen, K.Kawagoe, T.Kawamoto, R.K.Keeler, R.G.Kellogg, B.W.Kennedy, S.Kluth, T.Kobayashi, M.Kobel, S.Komamiya, T.Krämer, A.Krasznahorkay Jr., P.Krieger, J. von Krogh, T.Kuhl, M.Kupper, G.D. Lafferty, H. Landsman, D. Lanske, D. Lellouch, J. Letts, L. Levinson, J. Lillich, S.L. Lloyd, F.K. Loebinger, J. Lu, A. Ludwig, J. Ludwig, W.Mader, S.Marcellini, A.J.Martin, T.Mashimo, P.Mättig, J.McKenna, R.A.McPherson, F.Meijers, W.Menges, F.S.Merritt, H.Mes, N.Meyer, A.Michelini, S.Mihara, G.Mikenberg, D.J.Miller, W.Mohr, T.Mori, A.Mutter, K.Nagai, I. Nakamura, H.Nanjo, H.A.Neal, R.Nisius, S.W.O’Neale, A.Oh, M.J.Oreglia, S.Orito, C. Pahl, G. Pásztor, J.R.Pater, J.E. Pilcher, J. Pinfold, D.E.Plane, O. Pooth, M.Przybycień, A.Quadt, K.Rabbertz, C.Rembser, P.Renkel, J.M.Roney, A.M.Rossi, Y.Rozen, K.Runge, K. Sachs, T. Saeki, E.K.G. Sarkisyan , A.D. Schaile, O. Schaile, P. Scharff-Hansen, J. Schieck, T. Schörner-Sadenius , M. Schröder, M. Schumacher, R. Seuster , T.G. Shears, B.C. Shen, P. Sherwood, A. Skuja, A.M. Smith, R. Sobie, S. Söldner-Rembold, F. Spano, A. Stahl, D. Strom, R. Ströhmer, S. Tarem, M.Tasevsky, R.Teuscher, M.A.Thomson, E.Torrence, D.Toya, P.Tran, I. Trigger, Z. Trócsányi, E.Tsur, M.F.Turner-Watson, I. Ueda, B.Ujvári, C.F.Vollmer, P.Vannerem, R.Vértesi, M.Verzocchi, H.Voss, J. Vossebeld, C.P.Ward, D.R.Ward, P.M.Watkins, A.T.Watson, N.K.Watson, P.S.Wells, T.Wengler, N.Wermes, G.W.Wilson, J.A.Wilson, G.Wolf, T.R.Wyatt, S.Yamashita, D. Zer-Zion, L. Zivkovic School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK Dipartimento di Fisica dell’ Università di Bologna and INFN, I-40126 Bologna, Italy

4 Figures and Tables

Cite this paper

@inproceedings{Abbiendi2006QCDCA, title={QCD coherence and correlations of particles with restricted momenta in hadronic Z decays}, author={G . Abbiendi and Chris Ainsley and PHILIP {\AA}KESSON and Gavin Alexander and Georg Anagnostou and K . J . Anderson and Saori Asai and David Axen and IAN K . BAILEY and Elisabetta Barberio and T . Barillari and R. J. Barlow and Rachel Batley and P. Bechtle and Timo Behnke and Keaton Bell and P Joseph Bell and Gino Bella and Alain Bellerive and Giulia Benelli and Siegfried Bethke and Otmar Biebel and Oana Boeriu and Prezemek Bock and M . Boutemeur and Sylvie Braibant and Rafe M . Brown and H. J. Burckhart and Stefano Campana and P. Capiluppi and R . K . Carnegie and A . A . Carter and J. Ridge Carter and C-W Chang and D . G . Charlton and Caroline Ciocca and A. Csilling and M . Cuffiani and Stanislav Dado and A. De Roeck and Elke Wolf and Klaus Desch and B . Dienes and J . Dubbert and E . Duchovni and Guenter Duckeck and I . P . Duerdoth and Erez Etzion and Franco L. Fabbri and Pablo A. Ferrari and F. Fiedler and Ivor Fleck and MJ . Ford and Andrew Frey and Paula Gagnon and John Gary and Craig Gimbel and Giorgio Giacomelli and Piero Giacomelli and Marina Giunta and Jeff Goldberg and Eilam Gross and Jacob Grunhaus and Magali Gruwe and Philipp G{\"{u}nther and Arvind Gupta and Cs Hajdu and Marco Hamann and Gail G. Hanson and Arie Harel and Mathias Hauschild and C . M . Hawkes and Richard Hawkings and Gregor Herten and R . D . Heuer and Jenna C . Hill and Dezs{\"{o} Horv{\'a}th and P . Igo - Kemenes and Kazuei Ishii and H . Jeremie and Philipp Jovanovic and Tom Junk and J. Kanzaki and D . Karlen and K. Kawagoe and Tetsuaki Kawamoto and Rachael Keeler and Robert Givens Kellogg and Brandon Kennedy and Stefan Kluth and Takayoshi Kobayashi and Markus Kobel and Sachio Komamiya and Thomas Kr{\"a}mer and A . Krasznahorkay and PHILIP KRIEGER and Jacquelyn Krogh and Thorsten Kuhl and Michael Kupper and GEORGE D. LAFFERTY and Hagar Landsman and D . Lanske and D . Lellouch and James Letts and Lisa Levinson and J . Lillich and Sally L. Lloyd and F . K . Loebinger and Jianfang Lu and Arfst Ludwig and Jean Ludwig and Wolfgang Mader and S . Marcellini and Albert Martin and Tetsuro Mashimo and P. M{\"a}ttig and J A Mckenna and Ross A. McPherson and Frans Meijers and Wolfgang Menges and Frank S. Merritt and H . Mes and Nils Meyer and Alberto Michelini and Shozo Mihara and Giora Mikenberg and David J. Miller and W. Mohr and Takakazu Mori and ANDREAS MUTTER and Kei-ichi Nagai and IKU NAKAMURA and Hiroshi Nanjo and Homer A. Neal and Richard Nisius and Stephen Neale and Alexander Oh and Mark J Oreglia and Shintaro Orito and Christina Pahl and Gabriella P{\'a}sztor and Jessica Pater and J . E . Pilcher and Jessica Pinfold and David Plane and Oliver Pooth and M . Przybycień and Andr{\'e} Quadt and K. Rabbertz and C . Rembser and Peter Renkel and J . M . Roney and Ann Marie Rossi and Yaron Rozen and Karl Runge and KIRSTEN SACHS and Takaaki Saeki and E . K . G . Sarkisyan and A . D . Schaile and Otto Schaile and P. Hansen and Jim Schieck and T . Sch{\"{o}rner - Sadenius and Matthias Schr{\"{o}der and MarionB . Ansorge - Schumacher and Rolf Seuster and Tara Shears and Bing Shen and P. Greg Sherwood and Agnija Skuja and Arfon M. Smith and R . Sobie and S . S{\"{o}ldner - Rembold and F. Spano and Allan Stahl and Dolores Strom and Raimund Str{\"{o}hmer and Shlomit Tarem and Marek Ta{\vs}evsk{\'y} and Richard Teuscher and Mary Thomson and Eric Torrence and Daisuke Toya and Patrice Tran and ISABEL TRIGGER and Zolt{\'a}n Tr{\'o}cs{\'a}nyi and Elad Tsur and Mandy Watson and Isao Ueda and B . Ujv{\'a}ri and Carol Vollmer and P . Vannerem and R . V{\'e}rtesi and M . Verzocchi and Helga Voss and Joost Vossebeld and Chloe WARD and DE . Ward and Penelope Watkins and Agnes T Watson and Nigel Keith Watson and Philip Stephen Wells and Thorsten . Wengler and Norbert Wermes and George W. Wilson and Jeffrey A . Wilson and G . Wolf and Theresa R Wyatt and Shinji Yamashita and Danielle Zion and Lazar Zivkovic}, year={2006} }