Measurement of energy-energy correlations in e/sup +/e/sup -/. -->. hadrons at. sqrt. s = 29 GeV

Journal Article · Sat Jun 01 00:00:00 EDT 1985 · Phys. Rev. D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.31.2724· OSTI ID:5737448

Fernandez, E; Ford, W T; Qi, N; Read, Jr, A L; Smith, J G; Camporesi, T; De Sangro, R; Marini, A; Peruzzi, I; Piccolo, M; Ronga, F; Blume, H T; Hurst, R B; Sleeman, J C; Venuti, J P; Wald, H B; Weinstein, R; Band, H R; Gettner, M W; Goderre, G P ; Meyer, O A; Moromisato, J H; Shambroom, W D; von Goeler, E; Ash, W W; Chadwick, G B; Clearwater, S H; Coombes, R W; Kaye, H S; Lau, K H; Leedy, R E; Lynch, H L; Messner, R L; Moss, L J; Muller, F; Nelson, H N; Ritson, D M; Rosenberg, L J; Wiser, D E; Zdarko, R W; Groom, D E; Lee, H; Delfino, M C; Heltsley, B K; Johnson, J R; Lavine, T L; Maruyama, T; Prepost, R

The energy-energy correlation cross section for hadrons produced in electron-positron annihilation at a center-of-mass energy of 29 GeV has been measured with the MAC detector at SLAC. The result is corrected for the effects of detector resolution, acceptance, and initial-state radiation. The correlation is measured in two independent ways on the same data sample: the energy weights and angles are obtained either from the energy flow in the finely segmented total absorption calorimeters or from the momenta of charged tracks in the central drift chamber. This procedure helps reduce systematic errors by cross-checking the effects of the detector on the measurement, particularly important because the corrections depend on complex Monte Carlo simulations. The results are compared with the predictions of Monte Carlo models of complete second-order perturbative quantum chromodynamics and fragmentation, with the following conclusions: (1) fitting the asymmetry for large correlation angles gives values for ..cap alpha../sub S/ of 0.120 +- 0.006 in perturbation theory, 0.185 +- 0.013 in the Lund string model, and values which vary from 0.105 to 0.140 ( +- 0.01) in the incoherent jet models, depending on the gluon fragmentation scheme and the algorithm used for momentum conservation; and (2) the string fragmentation model provides a satisfactory description of the measured energy-energy correlation cross section, whereas incoherent jet formation does not.

• Research Organization: Department of Physics, University of Colorado, Boulder, Colorado 80309
• OSTI ID: 5737448
• Journal Information: Phys. Rev. D; (United States), Vol. 31:11
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ELECTRON-POSITRON INTERACTIONS
ANNIHILATION
HADRONS
PARTICLE PRODUCTION
CORRELATIONS
CROSS SECTIONS
FRAGMENTATION
GEV RANGE 10-100
GLUONS
MONTE CARLO METHOD
PEP STORAGE RINGS
PERTURBATION THEORY
QUANTUM CHROMODYNAMICS
STANFORD LINEAR ACCELERATOR CENTER
STRING MODELS
BASIC INTERACTIONS
COMPOSITE MODELS
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
ENERGY RANGE
EXTENDED PARTICLE MODEL
FIELD THEORIES
GEV RANGE
INTERACTIONS
LEPTON-LEPTON INTERACTIONS
MATHEMATICAL MODELS
NATIONAL ORGANIZATIONS
PARTICLE INTERACTIONS
PARTICLE MODELS
POSTULATED PARTICLES
QUANTUM FIELD THEORY
QUARK MODEL
STORAGE RINGS
US DOE
US ERDA
US ORGANIZATIONS
645102* - High Energy Physics- Particle Interactions & Properties-Experimental- Weak Interactions & Properties