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The sigma term and the quark number operator in QCD

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Zeitschrift für Physik C Particles and Fields

Abstract

We discuss the relationship of the forward matrix element of the operator\(\bar \psi \psi \), related to the so-called sigma term, to the quark number. We show that in the naive quark model in the canonical formalism these quantities coincide in the limit of small average quarkmomenta. In the QCD parton model defined through light-front quantization this result is preserved at leading perturbative order but it receives radiative corrections. We analyze the theoretical and phenomenological consequences of this result, which provides a bridge between a current algebra quantity, the sigma term, and a deepinelastic quantity, the parton number.

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Authors and Affiliations

  1. Dipartimento di Fisica Teorica, Università di Torino, Via P. Giuria 1, I-10125, Torino, Italy

    Mauro Anselmino

  2. Sezione di Torino, I.N.F.N., Via P. Giuria 1, I-10125, Torino, Italy

    Mauro Anselmino & Stefano Forte

Authors
  1. Mauro Anselmino
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  2. Stefano Forte
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Anselmino, M., Forte, S. The sigma term and the quark number operator in QCD. Z. Phys. C - Particles and Fields 61, 453–463 (1994). https://doi.org/10.1007/BF01413185

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  • DOI: https://doi.org/10.1007/BF01413185

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