Transverse and longitudinal Bose Einstein correlations in hadronic Z0 decays
Jan, 200019 pages
Published in:
- Eur.Phys.J.C 16 (2000) 423-433
e-Print:
- hep-ex/0002062 [hep-ex]
Report number:
- CERN-EP-2000-004
Experiments:
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Abstract: (arXiv)
Bose-Einstein correlations in pairs of identical charged pions produced in a sample of 4.3 million Z0 hadronic decays are studied as a function of the three components of the momentum difference, transverse ("out" and "side") and longitudinal with respect to the thrust direction of the event. A significant difference between the transverse, r_t_side, and longitudinal, r_l, dimensions is observed, indicating that the emitting source of identical pions, as observed in the Longitudinally CoMoving System, has an elongated shape. This is observed with a variety of selection techniques. Specifically, the values of the parameters obtained by fitting the extended Goldhaber parametrisation to the correlation function C'= C^{DATA}}/C^{MC} for two-jet events, selected with the Durham algorithm and resolution parameter ycut=0.04, are r_t_out=(0.647+-0.011(stat})+0.022-0.124(syst)) fm, r_t_side=(0.809+-0.009(stat)+0.019-0.032}(syst)) fm, r_l=(0.989+-0.011(stat)+0.030-0.015(syst})) fm and r_l/r_t_side=1.222+-0.027(stat})+0.075-0.012(syst). The results are discussed in the context of a recent model of Bose-Einstein correlations based on string fragmentation.- electron positron: colliding beams
- electron positron: annihilation
- Z0: electroproduction
- Z0: hadronic decay
- correlation: two-pion
- boson: statistics
- momentum: difference
- transverse momentum
- longitudinal momentum
- correlation function: parametrization
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