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Recherche transversale
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2008-06-26 - Article/Dans un journal avec peer-review - Anglais - 11 page(s)

Mathieu Vincent , Buisseret Fabien , Semay Claude , "Gluons in glueballs: spin or helicity?" in Physical Review. D : Particles and Fields, 77, Issue 11, 114022 (11 p.)

  • Edition : American Physical Society, College Park (MD)
  • Codes CREF : Physique des particules élémentaires (DI1221), Physique théorique et mathématique (DI1210)
  • Unités de recherche UMONS : Physique nucléaire et subnucléaire (S824)
  • Instituts UMONS : Institut de Recherche sur les Systèmes Complexes (Complexys)
  • Centres UMONS : Algèbre, Géométrie et Interactions fondamentales (AGIF)
Texte intégral :

Abstract(s) :

(Anglais) In the past decade, lattice QCD has been able to compute the low-lying glueball spectrum with accuracy. Like other effective approaches of QCD, potential models still have difficulties to cope with gluonic hadrons. Assuming that glueballs are bound states of valence gluons with zero current mass, it is readily understood that the use of a potential model, intrinsically noncovariant, could be problematic in this case. The main challenge for this kind of model is actually to find a way to introduce properly the more relevant degree of freedom of the gluon: spin or helicity. In this work, we use the so-called helicity formalism of Jacob and Wick to describe two-gluon glueballs. We show, in particular, that this helicity formalism exactly reproduces the JPC numbers which are observed in lattice QCD when the constituent gluons have a helicity-1, without introducing extra states as is the case in most of the potential models. These extra states appear when gluons are seen as spin-1 particles. Using a simple spinless Salpeter model with Cornell potential within the helicity formalism, we obtain a glueball mass spectrum which is in good agreement with lattice QCD predictions for helicity-1 gluons provided instanton-induced interactions are taken into account.

Identifiants :
  • DOI : 10.1103/PhysRevD.77.114022
  • arXiv : 0802.0088