Diquarks: a QCD sum rule perspective

We propose a phenomenological QCD sum rule with an explicit diquark field to investigate the essential ingredients inside the hadrons. Introducing the mass (m_\phi) and the condensate (\phi^2) for the diquark field as parameters in the model, we find that the sum rule works well for Lambda, Lambda_c and Lambda_b. This implies that these Lambda baryons can be represented by a diquark and a quark configuration. We also find that there is a duality relation among the parameters (m_\phi, \phi^2), for which the sum rule is equally good. In the limit when \phi^2 =0 we find m_\phi=0.4 GeV, which can be thought as the constituent diquark mass.Comment: 4 pages, 4 figures, revised version published in Phys. Rev.

QCD studies using a cone based jet finding algorithm for e+ e- collisions at LEP

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