Spin-String Interaction in QCD Strings

Abstract

I consider the question of the interaction between a QCD string and the spin of a quark or an antiquark on whose worldline the string terminates. The problem is analysed from the point of view of a string representation for the expectation value of a Wilson loop for a spin-half particle. A string representation of the super Wilson loop is obtained starting from an effective string representation of a Wilson Loop. The action obtained in this manner is invariant under a worldline supersymmetry and has a boundary term which contains the spin-string interaction. For rectangular loops the spin-string interaction vanishes and there is no spin-spin term in the resulting heavy quark potential. On the other hand if an allowance is made for the finite intrinsic thickness of the flux-tube, by assuming that the spin-string interaction takes place not just at the boundary of the string world-sheet but extends to a distance of the order of the intrinsic thickness of the flux tube, then we do obtain a spin-spin interaction which falls as the fifth power of the distance. Such a term was previously suggested by Kogut and Parisi in the context of a flux-tube model of confinement.

19 pages, 1 figure; Published version with added discussion and references in section 5

References in corpus (14)

• Effective field theories for heavy quarkonium
• QCD forces and heavy quark bound states
• Quark confinement and the bosonic string
• Confining Strings
• The QCD potential at O(1/m^2): Complete spin-dependent and spin-independent result
• A consistent derivation of the quark--antiquark and three quark potentials in a Wilson loop context
• String Theory and the Size of Hadrons
• Heavy Quarkonia: Wilson Area Law, Stochastic Vacuum Model and Dual QCD
• Comparing the Nambu-Goto string with LGT results
• Confinement: Understanding the Relation Between the Wilson Loop and Dual Theories of Long Distance Yang Mills Theory
• String-like behaviour of 4d SU(3) Yang-Mills flux tubes
• Hidden Symmetries of Large N QCD
• Quark Spin and the Theta-Term for the QCD String
• QCD strings with spinning quarks

Cited by in corpus (4)

• Intrinsic Thickness of QCD Flux-Tubes
• Asymmetry in ${\Lambda }_b$ and ${\bar{\Lambda }}_b$ production
• Renormalized Kalb-Ramond model: duality and generalized potential
• Flux-tubes in confining gauge theories with gravitational dual