Hadron production and QCD coherence at LEP Marco Cuffiani University of Bologna and INFN (Italy) on behalf of the OPAL Collaboration QCD coherence and.

Slides:

Advertisements

Similar presentations

1 ON THE HIGH ORDER MULTIPLICITY MOMENTS K. Fiałkowski, R. Wit Jagellonian University.

Advertisements

Anomalous Pion Production in High Energy Particle Collisions Alexander Bylinkin, Andrey Rostovtsev XV Moscow School of Physics XXXX ITEP Winter School.

Bose-Einstein and Fermi-Dirac Correlations at LEP and HERA Ignacio Aracena University of Bern Outline Introduction Bose-Einstein and Fermi-Dirac Correlations.

Jet and Jet Shapes in CMS

ISDM 2005, Kromeriz Kamil Sedlak, Jets in photoproduction at HERA 1 Jets in Photoproduction & at low Q 2 at HERA On behalf of the H1 and ZEUS Collaborations.

Julia Velkovska Selected CMS Results from pp collisions 27th Winter Workshop on Nuclear Dynamics Winter Park, Colorado Feb 6-13, 2011.

Thomas D. Gutierrez UC Davis 1 Saturday October 12, 2002 APS DNP Meeting, Lansing, MI Pion HBT from pp Collisions at STAR Thomas D. Gutierrez For the STAR.

University of Gaziantep Department of Engineering Physics August 2006 Page 1/18 A.Beddall, A.Beddall and A. Bingül Department of Engineering Physics University.

Leszek Zawiejski XXXIII ISMD, September Bose – Einstein Correlations in DIS at HERA XXXIII International Symposium on Multiparticle Dynamics, Cracow,

STAR Collaboration Meeting, UCD group meeting, February Ultra Peripheral Collisions What is a UPC? Photonuclear interaction Two nuclei “miss” each.

A Comparison of Three-jet Events in p Collisions to Predictions from a NLO QCD Calculation Sally Seidel QCD’04 July 2004.

Ursula Bassler, LPNHE-Paris, RUN II MC workshop 1 Monte Carlo Tuning: The HERA Experience Monte Carlo Models for DIS events Description of inclusive hadronic.

Fragmentation in e + -e  Collisions Dave Kettler Correlations and Fluctuations Firenze July 7-9, 2006 p hadron ee e+e+ , Z 0 LEP PETRA color dipole.

 s determination at LEP Thorsten Wengler University of Manchester DIS’06, Tsukuba, Japan.

Nov 2001 Craig Ogilvie 1 Angular Correlations at High pt: Craig Ogilvie for the Phenix Collaboration Energy-loss: increased medium-induced gluon-radiation.

CDF Joint Physics Group June 27, 2003 Rick FieldPage 1 PYTHIA Tune A versus Run 2 Data  Compare PYTHIA Tune A with Run 2 data on the “underlying event”.

Inclusive Jets in ep Interactions at HERA, Mónica V á zquez Acosta (UAM) HEP 2003 Europhysics Conference in Aachen, July 19, Mónica Luisa Vázquez.

As one evolves the gluon density, the density of gluons becomes large: Gluons are described by a stochastic ensemble of classical fields, and JKMMW argue.

Working Group C: Hadronic Final States David Milstead The University of Liverpool Review of Experiments 27 experiment and 11 theory contributions.

1 Inclusive Photoproduction of ρº, K*º and φ Mesons at HERA Andrei Rostovtsev (ITEP) ‏ on behalf of H1 Collaboration Published in H1 Collab., Phys. Lett.

Mean Charged Multiplicity in DIS, Michele Rosin U. WisconsinZEUS Monday Meeting, Apr. 18th Preliminary Request: Mean Charged Multiplicity in DIS.

Particle Physics Chris Parkes Experimental QCD Kinematics Deep Inelastic Scattering Structure Functions Observation of Partons Scaling Violations Jets.

Optimization of parameters for jet finding algorithm for p+p collisions at E cm =200 GeV T. G. Dedovich & M.V. Tokarev JINR, Dubna  Motivations.

Fermilab MC Workshop April 30, 2003 Rick Field - Florida/CDFPage 1 The “Underlying Event” in Run 2 at CDF  Study the “underlying event” as defined by.

The centrality dependence of high p T π 0 production in d-Au collisions Abstract Michael Kordell II, Abhijit Majumder Wayne State University, Detroit,

Francesco Noferini Bologna University Erice, Italy 31 st August 2006 Two-particle correlations: from RHIC to LHC.

Andrei Rostovtsev Moscow, ITEP Low-x, June 2013 (Eilat) On behalf of H1 Collaboration.

Event Shapes, Alexander Savin University of WisconsinDIS 2006, April 21, Event Shapes in NC DIS at ZEUS Alexander A. Savin University of Wisconsin.

Jets and α S in DIS Maxime GOUZEVITCH Laboratoire Leprince-Ringuet Ecole Polytechnique – CNRS/IN2P3, France On behalf of the collaboration On behalf of.

ISMD 2004, Sonoma State University R. Muresan NBI BEC studies 1 Raluca Muresan NBI Copenhagen Bose-Einstein Correlation Studies at HERA-B.

Andrey Korytov, University of Florida ISMD 2003 September 5-11, 2003, Kraków Soft QCD Phenomena in High-E T Jet Events at Tevatron Andrey Korytov for CDF.

Inha Nuclear Physics Group Quantum Opacity and Refractivity in HBT Puzzle Jin-Hee Yoon Dept. of Physics, Inha University, Korea John G. Cramer,

Recent multiplicity studies at ZEUS, Michele Rosin U. WisconsinHadron Structure 2004, Sept. 1st University of Wisconsin, Madison on behalf of the.

24/08/2009 LOMONOSOV09, MSU, Moscow 1 Study of jet transverse structure with CMS experiment at 10 TeV Natalia Ilina (ITEP, Moscow) for the CMS collaboration.

Implications for LHC pA Run from RHIC Results CGC Glasma Initial Singularity Thermalized sQGP Hadron Gas sQGP Asymptotic.

Charged Particle Multiplicity, Michele Rosin U. WisconsinQCD Meeting May 13, M. Rosin, D. Kçira, and A. Savin University of Wisconsin L. Shcheglova.

Mean Charged Multiplicity in DIS, Michele Rosin U. WisconsinZEUS Collaboration Meeting, Oct. 21st Analysis Update: Mean Charged Multiplicity in.

Color Reconnection in W Pair Events Guillaume Leibenguth Université Catholique de Louvain Belgium DIS 2003, St. Petersburg On behalf of the LEP collaborations.

Jorgen D’Hondt University of Brussels - DELPHI Collaboration l WW  qqQQ events collected at LEP2 l Colour Reconnection effect at LEP2 l Model dependent.

Two particle correlations: from RHIC to LHC Francesco Noferini Bologna University INFN – sez. Bologna ALICE-TOF Tuesday, May 16th Villasimius (Italy) HOT.

1 Proton Structure Functions and HERA QCD Fit HERA+Experiments F 2 Charged Current+xF 3 HERA QCD Fit for the H1 and ZEUS Collaborations Andrew Mehta (Liverpool.

Joshua Moss (Ohio State University) on behalf of the ATLAS Collaboration ICHEP 2012, Melbourne 6 July 2012 ATLAS Electroweak measurements of W and Z properties.

University of Antwerpen, Belgium On behalf of the LEP experiments

Review of ALICE Experiments

EHS/NA22 Collaboration Na Li Institute of Particle Physics

Offline meeting Azimuthally sensitive Hanbury-Brown-Twiss (HBT) Interferometry Lukasz Graczykowski Warsaw University of Technology Johanna.

(representing DELPHI coll.)

Event Shapes in NC DIS at ZEUS

Implications of First LHC Data: Underlying Event Measurements

Analysis Update: Mean Charged Multiplicity in DIS

N. ILINA, V. GAVRILOV (ITEP, Moscow)

Example analysis of toy model

Tatia Engelmore, Columbia University

Charged Particle Multiplicity in DIS

Open Heavy Flavour Production at HERA

Edgar Dominguez Rosas Instituto de Ciencias Nucleares

Analysis Update: Mean Charged Multiplicity in DIS

Study of Multiplicity and Event Shapes using ZEUS detector at HERA

Study of Multiplicity and Event Shapes using ZEUS detector at HERA

Event Shape Analysis in minimum bias pp collisions in ALICE.

K0S and L production at ZEUS

Event Shape Variables in DIS Update

Analysis Update: Mean Charged Multiplicity in DIS

Charged Particle Multiplicity in DIS

kT Asymmetry in Longitudinally Polarized ｐｐ Collisions

Preliminary Request: Mean Charged Multiplicity in DIS

Jet fragmentation results at CDF

Outline of the talk: ● Introduction ● QCD models

Dalian University of Technology, Dalian, China

Hadron Formation in Nuclei in Deep-inelastic Scattering

Presentation transcript:

Hadron production and QCD coherence at LEP Marco Cuffiani University of Bologna and INFN (Italy) on behalf of the OPAL Collaboration QCD coherence and correlations of particles with restricted momenta in hadronic Z decays (abstract 601) Bose-Einstein study of position-momentum correlations of charged pions in hadronic Z decays (abstract 708)

In a QCD cascade the presence of one gluon enhances the probability for further gluon emissions, causing positive correlations: the multiplicity distribution of partons in a jet is broader than a Poisson distribution. Due to the angular ordering induced by colour coherence, gluons produced with bounded transverse momenta p T < p T cut become, for small p T cut, independently emitted from the primary parton: the multiplicity distribution of partons becomes Poissonian. Correlations among particles may be measured in terms of the (normalized) factorial moments F q and cumulants K q of order q = 2, 3, 4...., in a region  of phase space QCD coherence and correlations of particles with restricted momenta in hadronic Z decays

Marco Cuffiani, EPS HEP Expectations from QCD DLLA calculations (S.Lupia, W.Ochs, J.Wosiek, Nucl.Phys. B 540 (1999) 405.) cylindrically-cut phase space (p T < p T cut ) spherically-cut phase space (p < p cut ) compare QCD predictions with data, under the hypothesis of LPHD

4 Poisson limit masked by hadronization effects as p T cut Q 0 The factorial moments PYTHIA + BE 32 good agreement with data multiplicity of charged particles in a single event hemisphere

Marco Cuffiani, EPS HEP K 2 = F 2 – 1 (not shown) measure the genuine correlations among hadrons the strong rise of the factorial moments as p T cut 0 GeV is predominantly due to genuine correlations among particles The cumulants

Marco Cuffiani, EPS HEP Compare with e + p: ZEUS DIS events in the current region of the Breit frame (Phys.Lett.B 510 (2001) 36) mimic ZEUS experimental conditions exclude part of the central rapidity region select two jet events by requiring thrust > 0.96 the minimum around p T cut = 1 GeV disappears.

Marco Cuffiani, EPS HEP In the case of a dynamic source of pions, the expansion leads to correlations between the space-time emission points and the particle 4-momenta (position-momentum correlations). The dimensions of the regions of homogeneity for Bose-Einstein correlations depend on the momentum of the emitted particles. Study three-dimensional BE correlation functions in bins of the pair average transverse momentum k t and of the pair rapidity | Y |. Bose-Einstein study of position-momentum correlations of charged pions in hadronic Z 0 decays Two different sets of variables, components of the pair 4-momentum difference : (Q l,Q t_side,Q t_out ) and (q t,q l,q 0 )

8 (Q l,Q t_side,Q t_out ) in the LCMS (the same analysis, not differential in |Y| and k t, was presented in Eur. Phys. J. C 16 (2000) 423)

9 (q t,q l,q 0 ) in the CMS qlql qtqt 1 2 q 0 = E 1 – E 2 thrust axis

Marco Cuffiani, EPS HEP the Bertsch-Pratt with parameters: N,, R 2 long, R 2 t_side, R 2 t_out, R 2 long,t_out and the Yano-Koonin with parameters: N,, R 2 t, R 2 l, R 2 0, v  2 = 1/(1-v 2 )  Two parameterizations have been fit to the experimental correlation functions

Marco Cuffiani, EPS HEP Bertsch-Pratt fits

Marco Cuffiani, EPS HEP Yano-Koonin fits

Marco Cuffiani, EPS HEP The Yano-Koonin rapidity plotted as a function of the pair rapidity | Y | Y YK ≈ 0 for all | Y | in the case of a static source Y YK = | Y | for a source which expands boost- invariantly. Y YK vs |Y|

Marco Cuffiani, EPS HEP BP parameters may be compared with YK parameters: for a boost-invariant source,  LCMS = 0, so that:

Marco Cuffiani, EPS HEP longitudinal radii transverse radii “time parameters”

Marco Cuffiani, EPS HEP summary Large influence of the hadronization stage on the multiplicity distributions in restricted phase-space regions, inconsistent with the expectations of the LPHD hypothesis. MC models including hadronization reproduce the data qualitatively. BEC, as implemented in PYTHIA, improve significantly the agreement. BEC correlation lengths depend on k t. Y YK scales approximately with |Y|, in agreement with a nearly boost- invariant expansion of the source of pions. Similar results have been observed in pion sources created in more complex systems (pp and collisions between heavy nuclei)